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A Study of Fe3O4@ Si18O27 Catalyst Through Statistical-Nucleus Independent Chemical Shifts(S-NICS) Method

Neda Samiei Soofi and Majid Monajjemi

Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran.

Corresponding Author E-mail: m_monajjemi@srbiau.ac.ir

DOI : http://dx.doi.org/10.13005/ojc/320504

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ABSTRACT:

There are no theoretical or mathematical reports of a statistical approach in NMR shielding and nucleus independent chemical shifts, while the asymmetry (η) and skew (κ) parameters are fluctuated in short distances and are alternative in long distances. In the case of axially symmetric tensor, σ22 equals either σ11 or σ33, skew is κ= ±1 and by changing asymmetry between 0 ≤ η ≤ +1 skew will be changed between -1 ≤ κ ≤ +1 , meanwhile the parameter “κ” is zero when σ22 = σiso. In this work, we have investigated a statistical method by computing of Nucleus-Independent Chemical Shifts (S-NICS) in point of probes motions in a sphere of shielding and deshielding spaces of SiO2 rings. Monajjemi in the previous work [24], has  investigated a new method as the name “ S-NICS” which this method is  suitable for calculation the aromaticity in the non-benzene rings such as SiO2 rings which is a famous catalyst for organic chemical synthesize and reaction. Although S-NICS values for some molecules such as benzene, borazine and naphthalene can be indicated as the aromaticity criterion, for other cases such as BnNnHx and their hydrogenated derivatives, these values indicate electromagnetic index. Finally, we have introduced a schematic diagram of statistical-nucleus independent chemical shifts for ab-initio calculations in Gaussian program, Games or other software.

KEYWORDS:

naphthalene; electromagnetic index; NMR shielding

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Soofi N. S, Monajjemi M. A Study of Fe3O4@ Si18O27 Catalyst Through Statistical-Nucleus Independent Chemical Shifts(S-NICS) Method. Orient J Chem 2016;32(5). Available from: http://www.orientjchem.org/?p=22352


Introduction

Electronic towards the structural aspects have proved to be an important key in physical organic chemistry in the explanation of structures, reactivity and stabilities of various organic compounds and natural product molecules1 .

The chemical shift of a nucleus in molecular rings occurs from the nuclear shielding effect of an applied magnetic field. The magnitude of such an induced magnetic field is commensurate with the stability of the applied external magnetic field (B0).  Thus the effective field (Beff) at the nucleus is given by Beff B0 (1− σi), where “1” is the unit matrix and σi is the second-rank nuclear shielding matrix. In ordinary NMR experiments B0 is a uniform field along the z-axis and the resonance NMR frequency, νi, of a given nucleus in a molecule is therefore dependent to its gyromagnetic ratio, γi, as specified by νi = (γi/2π)B0(1 − σi)2.

The nucleus-independent chemical shift (NICS) is a computational method that calculates the absolute magnetic shielding at the center of the ring taken with reversed sign. Negative NICS values indicate aromaticity and positive values antiaromaticity3-5 .

For further investigation of aromaticity, another method called the harmonic oscillator model of aromaticity (HOMA)6 has been applied, and is distinguished as a normalized sum of the squared deviations of bond length from the normal value7.An aromatic compound has a HOMA value of one whereas a non-aromatic compound has the value 0.

Several criteria for explanation of aromaticity can be considered and may divided into five categories, which are: (1) the energetic approach to aromaticity (2) geometrical considerations (3) reactivity of aromatic compounds (4) magnetic parameters of aromaticity8-10, and the (5) Statistical-Nucleus-Independent Chemical Shifts approach (S-NICS) which is the subject of this work.

In using the energetic criterion for establishing the aromaticity of a compound, it is evident that the excess of stability of the structure is due to cyclic electron delocalization relative to suitable references systems11-12 . Moreover, Cooper, Gerratt, and Raimondi13 have developed some appropriate reference systems for calculation of the resonance energy. In using structural considerations, the geometry should show a decrease in aromaticity of bond alternation which have been reported by Julg and Kruszewski in several quantitative measurements14 . Monajjemi and Boggs have shown the low aromaticity of borazine in the rings of B18N18 and B15N15 by the non-bonded interaction method15-18 .

Regarding NMR chemical shifts and diamagnetic susceptibilities, protons attached to aromatic rings typically undergo a downfield shift from the olefin region; therefore, an up-field shift appears in the proton NMR spectrum19 . So aromaticity can be defined as the ability of a compound to sustain an induced ring current, these compounds are then called dia-tropic and antiaromatic compounds are called Para-tropic. NMR chemical shifts and diamagnetic susceptibilities , anisotropy is important when measuring a compound’s aromaticity 20.

Recently aromaticity in terms of nucleus-independent chemical shifts in long distances of NICS (1, 2.5, 3, and 3.5) Å, around the ring center, NICS (0), at the center of ring plane and aromatic ring current shielding (ARCS) were compared in several studies. In short range of distances (r<0.3) there are no theoretical or mathematical reports of statistical approach in nucleus independent chemical shift calculations, while the asymmetry (η) and skew (κ) parameters fluctuate in behavior around the center of rings.

For further discussion of statistical approach in nucleus independent chemical shift calculations, especially in short range of distances, we have focused in relaxations of CAS, dipole-dipole and contribution 21. We have shown that the asymmetry (η) and skew (κ) parameters fluctuate in behavior around the center of rings due to minimum isotropy in the center. The most fluctuations are appearing around the minimum or maximum functions mathematically.

Nuclear spin relaxation studies in the gas phase had started in 1987 22. Spin-relaxation data in the gas phase provide a stringent test of the anisotropy of an existing intermolecular potential. In some cases, spin-relaxation data is a powerful test of the anisotropic part of the intermolecular interaction. There are other observables such as the Beenakker effects, depolarized Rayleigh scattering, sound absorption, and pressure broadening of rotational lines in the IR, which are also sensitive to the anisotropy of the potential 23.

The basis of this work is on random motions of probes in the shielding and deshielding spaces of aromatic and antiaromatic molecules to consider maximum abundant of points in due to dipole–dipole, CSA and contribution relaxations. The main purpose of random displacement of various probes inside of shielding and deshielding spaces are for understanding of mechanism and consequences of anisotropic spin–spin interactions in short ranges, Although the relaxation of proton and hydrogen probes are much less, than the large ion probes such as Li+.

In CSA, relaxation Chemical shift anisotropy (CSA) originates from the orientation dependence of the chemical shift, and hence changes under rotation of the molecule and induces minor variations in the magnetic field at the site of the nucleus.

The time dependence of anisotropic interactions does however contribute to relaxation but the average amount can be time independent.

In this study, the major components of Haeberlen parameters, and chemical shift anisotropy (CSA) tensors have been calculated for borazine, benzene, naphthalene, BnNnHx rings (n=12, 15, 18) and B3N3Hn (n = 0, 2, 4, 6, 8,). The numerous random points around the center of those molecules have been produced by generation of pseudo-random numbers, which are distributed in a Gaussian function in the interval [0, 1).

The hydrogenated and dehydrogenated structures of borazine and BnNn rings have been investigated to understand more about the unknown parameters of those rings in point of electromagnetic, aromaticity, delocalization mechanism, conjugated system and hyperactive conjugation in BN alternate systems. Therefore, the hydrogenation and dehydrogenation of borazine has moved gradually in two directions toward cyclotriborazane (B3N3H12) and B3N3 respectively .

Our result has been compared by the energy decomposition analysis (EDA) method . The total  bonding energy and the  conjugation between three B-N  bonds in borazine is significantly smaller than that for benzene and magnetically properties shows a singular behavior in borazine and B3N3Hx rings .

Fowler and Steiner computed the total current density induced by a magnetic field perpendicular to the molecular plane of borazine. They found that the  currents are localized in three islands of circulation on the nitrogen atoms and concluded that borazine is moderately aromatic . Nucleus-independent chemical shift values (NICS) show a little and no evidence of ring currents, indicating with no aromaticity for borazine due to the polar B–N bond .In contrast, the S-NICS data shows a weak but stable aromaticity for borazine according to the 1999 definition provided by IUPAC definition of aromaticity.

We have optimized various isomers of B3N3 and B4N4 to understand which members of each group are more stable.  Scheme 1 shows that in both groups the planar ring isomer of B3N3 and B4N4 with B and N alternate are more stable than the others.

We have discussed the electronic properties in their structures to find the reason for relative stability in these rings in point of isotropy and anisotropy. Finally the electronic structures of BnNn rings of (B3N3) N for (N= 4, 5, 6) of B12N12, B15N15 and B18N18 has been studied by S-NICS method 24.

Magnetite (Fe3O4) is the earliest discovered magnet which crystallizes in the inverse cubic spinel structure. Each cubic spinel cell contains eight interpenetrating oxygen and the tetrahedral sites, occupied by one-third of the iron atoms, form a diamond structure. The remaining Fe atoms are located at the octahedral sites with the nearest-neighbor atoms lined up as strings along six different [110] directions. In other words Fe3O4 consists of a cubic close packed array of oxide ions where all of the Fe2+ ions occupy half of the octahedral sites and the Fe3+ are split evenly across the remaining octahedral sites and the tetrahedral sites .

Both FeO and γ-Fe2O3 have a similar cubic close packed array of oxide ions and this accounts for the ready interchangeability between the three compounds on oxidation and reduction as these reactions entail a relatively small change to the overall structure therefore, Fe3O4 samples can be non-stoichiometric25 .

Fe3O4 is ferromagnetic with a curie temperature of 858 K and The ferromagnetism of Fe3O4 arises because the electron spins of the FeII and FeIII ions in the octahedral sites are coupled and the spins of the FeIII ions in the tetrahedral sites are coupled but anti-parallel to the former. Fe3O4 is used as a catalyst in the Haber process and in the water gas shift reaction .

The latter uses an HTS (high temperature shift catalyst) of iron oxide stabilized by chromium oxide . This iron-chrome catalyst is reduced at reactor start up to generate Fe3O4 from α-Fe2O3 and Cr2O3 to CrO3 . Fe3O4 is an electrical conductor with conductivity significantly higher than Fe2O3, and this is ascribed to electron exchange between the FeII and FeIII centers 25

Magnetite particles are of interests in bioscience applications such as in magnetic resonance imaging (MRI) since iron oxide magnetite nanoparticles represent a non-toxic alternative to currently employed gadolinium-based contrast agents. However, due to lack of control over the specific transformations involved in the formation of the particles, truly super paramagnetic particles have not yet been prepared from magnetite, i.e. magnetite nanoparticles that completely lose their permanent magnetic characteristic in the absence of an external magnetic field .
As a half-metallic material, Fe3O4 shows normal metallic behavior in the minority spin, while
at the same time there is a gap of~0.5 eV in the majority spin at the Fermi level. From an itinerant point of view, the high conductivity (~250 -1 cm-1) of the high-temperature phase is a natural consequence of the partially filled 3 d band of the octahedral -site Fe atoms .

Production of nano-particles can be performed chemically by taking for example mixtures of FeII and FeIII salts and mixing them with alkali to precipitate colloidal Fe3O4. The reaction conditions are critical to the process and determine the particle size .Nano particles of Fe3O4 are used as contrast agents in MRI scanning.Magnetic nanoparticles have attracted much interest not only in the field of magnetic recording but also in the areas of medical field of magnetic sensing. Especially, nanoparticles of iron oxide are reported to be applicable as a material for use in drug delivery systems, cancer therapy and MRI .

On the other hand, most of the applications require magnetic particles to disperse in a non-magnetic matrix. The matrixes play an important role in determining physical properties of the composite nanoparticle in addition to providing a means of particle dispersion.

Another important characteristic of the matrix is to act as the protection of magnetic nanoparticles against corrosion or oxidation especially in the case of metallic nanoparticles . Among carbon-based or oxide matrixes such as silica, alumina, titanic oxide or zeolite, silica can be a most suitable material for the matrix because of its non-toxicity, inertness to magnetic field and easiness to form cross-lined network structure .

Silica surfaces are chemically stable, biocompatible and can be easily functionalized for bio conjugation purpose. Hence silica-coated magnetite composite nanoparticles (Fe3O4@SiO2) have been synthesized by many groups . Recently, silica coated magnetite functionalized with γ-mercapto-propyl-trimethoxy-silane have been successfully applied to extract Cd2+, Cu2+, Hg2+, and Pb2+ from water in a wide pH range .

Catalysts play a very important role in modern science and technology as they improve reaction yields; reduce temperatures of chemical processes in synthesis.There are two main types of catalysis, heterogeneous, where the catalyst is in the solid phase with the reaction occurring on the surface and homogeneous, where the catalyst is in the same phase as the reactants .

The heterogeneous catalysts can be readily separated from the reaction mixture but the reaction rate is restricted due to their limited surface area . Meanwhile homogeneous catalysts can react very fast and provide a good conversion rate per molecule of the catalyst, but since they are miscible in the reaction medium, it can be a painstaking process to remove them from the reaction medium . The difficulty in removing homogenous catalysts from the reaction medium leads to problems in retaining the catalyst for reuse . The bridge between heterogeneous and homogeneous catalysts can be achieved through the use of Fe3O4 nanoparticles . Fe3O4 particularly is useful and important group of nanoparticles in the magnetic nanoparticles (MNPs) groups which show strong magnetic moments that are rarely retained outside of the presence of an external magnetic field. These nanoparticles may be composed of a series of materials such as metals like cobalt and nickel, alloys like iron/platinum and metal oxides like iron oxides26 .and ferrites27.Fe3O4 Nanoparticles of silica catalytic material provide the benefit of increased surface area which allows for an increased reaction rate28. Moreover, nanoparticles can permit additional catalytic functionalities due to their unique properties29.As instance, the MNPs being used to extract selected cells from biological samples and cultures30.

A few catalysis of magnetic nanostructures have been developed up to now, including the preparation of nanocomposite materials consisting of magnetic core nanoparticles which have been coated by the shell of other catalytically active nanomaterials. Another type of catalyst which is of interest for organic synthesis involves the use of organic molecules. These molecules show a large degree of specificity for their reactions and may allow a more successful reaction than conventional chemistry. Overall, the binding of catalysts to magnetic nanoparticles allows the retention of these materials after the end of the reaction for reuse.

Theoretical Background

NMR Shielding

The reduced anisotropy

Vol32No5_stud_Shif_for1

and anisotropy (Δσ) with relation of

Vol32No5_stud_Shif_f1

including shielding asymmetry (η) can be defined as:

Vol32No5_stud_Shif_for2.3

In some cases of an axially symmetric tensor,

Vol32No5_stud_Shif_f2

will be zero and hence η = 0. However, the asymmetry (η) parameter indicates that how much the line figure deviates from an axially symmetric tensor, therefore, (0 ≤ η ≤ +1).

The shielding tensor can be expressed as the sum of a symmetric, an anti-symmetric, and a scalar terms, which are rank 2, rank 1 and rank zero tensors respectively as:

Vol32No5_stud_Shif_f3

The total chemical shielding tensor “r” is a non-symmetric tensor that can be decomposed into three independent tensors as: (1), an isotropic component, (2) a traceless symmetric component, and (3) a traceless anti-symmetric component . In spherical tensor representation, as Haeberlen  have pointed out, at a fundamental level tensors are better represented in spherical fashion, such that a general second-order property “σ” may be written as

Vol32No5_stud_Shif_for4

where the number in brackets refers to tensor rank. Spherical tensors are intrinsically involved in considering  the effects of  tensor quantities on density matrix  evolution  , so  the use of  this representation  is  inevitable  for such  work. It is worth noting that:

Vol32No5_stud_Shif_f4

and

Vol32No5_stud_Shif_for5

The proportionalities  in  these equations  indicate that  shielding  anisotropy  and  asymmetry  can readily  be  related  to  spherical  tensor  components,  thus  facilitating  theoretical interpretation,  whereas  the  relation  between  spherical  tensor  components  and  span/skew  is more  obscure.  The isotropic tensor can be represented by a scalar average as :

Vol32No5_stud_Shif_for6

The symmetric component of the shielding tensor has tensor elements with rij = rji. This tensor is responsible for the CSA relaxation most often described in the literature and can be  diagonalized by rotation into the shielding tensor principal coordinate system.The anti-symmetric tensor also induces CSA relaxation but this is almost impossible to measure because the induced effects are close to parallel to the external magnetic field which cannot be diagonalized.

By this work, in a statistical calculation we have shown that a time independent average of (Ω*) can be replaced of all above sum of asymmetric, an anti-symmetric, and a scalar terms, which are rank 2, rank 1 and rank zero tensors respectively. This method is based on random motions of probes in the shielding and deshielding spaces of aromatic and antiaromatic molecules to consider maximum abundant of relaxations points in due to dipole–dipole and spin –dipole interactions.

The magnetic environment of a spin is seldom isotropic. Therefore, is represented by a tensor of Span.

Vol32No5_stud_Shif_for7.8

In the Herzfeld-Berger notation , tensors have explained by three parameters, which they are combination of the major components in the standard notation. Those are including, the span (Ω), which describes the maximum width of the model, (Ω ≥ 0), and the skew (κ) of the tensor which is a magnitude of the values.

The accurate formulation of the span (Ω), including the factor of (1-σref) has been described by Ω = (σ33– σ11) (1-σref) (9). In the Haeberlen-Mehring-Spiess notation, different combinations of the major components are used to explain the line figure, and is needed the major components become orderly according to their segregation from the isotropic value in this convention

The CSA relaxation rates depend on the anisotropy parameter in the standard parameters, of the shielding tensor, (σ11, σ22, σ33), are labeled according to the IUPAC rules, and they formalized and adopt the high frequency-positive order. Therefore, σ33 corresponds to the direction of minimum shielding, with the highest frequency, whenever σ11 corresponds to the direction of maximum shielding, with the lowest frequency .

Moreover the orientation of asymmetry tensoris given by

Vol32No5_stud_Shif_f5

; (-1 ≤ κ ≤ +1), and related on the position of σ22 with consideration of σiso, the sign of κ is either positive or negative.

Based onour calculations especially various BnNn Rings, Benzene and naphthalene, (κ) is mostly positive31-40, and the negative values are belong to some critical or boundary points. In the case of an axially symmetric tensor, σ22 equals either σ11 or σ33 and κ= ±1 thereforea = Ω/3, and the parameter a” and “κ” are zero when σ22 = σisoand the parameter “μ” used with the Herzfeld-Berger is related to the span of a tensor. Meanwhile, the spinning rate is given by μ = Ω*νref,

For a non-zero anti-symmetric tensor [44] give the relaxation rates

Vol32No5_stud_Shif_for10

and ρ2  is defined by:

Vol32No5_stud_Shif_for11

Vol32No5_stud_Shif_for12

Where and   correspond to the correlation times for isotropic tumbling and small-step molecular rotation, respectively and in the case of axial symmetry (η=0) or for isotropic tumbling .

Based on recent works41-66, in this study, we consider a model of SiO2 rings as a molecule for Fe3O4@SIO2 catalyst using ab initio calculations within the density functional theory (DFT) for calculating the aromaticity of rings for organic calculations.

Results and Discussion

Total shielding constants, orientations of the principal axes such as standard components,Haeberlen-Mehring, and Herzfeld-Berger parameters for Fe3O4@Si18O27 in various statistical situations have been calculated by DFT methods and the data are listed in tables1-5.

In short distances of region around the molecular centers, the asymmetric parameter (η),and the skew (κ), exhibited Gaussian distribution based on their fluctuation behavior, which is dependent on their distances from the center of the molecular rings.In contrast, of those parameters, the isotropy does not have a fluctuating behavior and it increased by increasing its distance from the center of the rings with a linear relationship. The slopes of these lines are changed, and among the levels of various distances for isolated Si18O27 and Fe3O4@Si18O27(less than 0.2 Å and more than 0.2 Å for SiO2 ring, less than 0.25 Å and more than 0.25 Å for Fe3O4@Si18O27)(Fig.1).

The isotropy during the replacing of Fe3O4@sio2 are positive which indicates negative values for aromaticity,but the slopes are decreased from the replacing from 0.1 to center (Fig.1).

As we have shown in Fig.1-7, the slopes of aromaticity curves versus distances to the center of the Fe3O4@SiO2 ring are decreased by decreasing the distances gradually which indicates distortion of aromatic electronic structures, and on the other hand these slopes are increased by increasing the distance,emphasizing a special electronic structure in Fe3O4@SiO2. Therefore, S-NICS has an increased ability to identify exact points in the area of shielding space byaromaticity criterion in such compounds via Monte Carlo stochastic calculation.

In all previous works [3,10], different basis sets yielded isotropies of various magnitude, and the criterion ofaromaticity cannot be certain by using different methods, because in multiple calculations the numerous basis sets can evaluate different isotropies for two situations of one aromatic molecule.

It is acceptable that the difference between isotropies in NICS values can express the quality of the distinct aromaticity for a few molecules, but these differences between isotropies are not able to express the mechanism of aromaticity as well as S-NICS.

In theS-NICS method via the statistical calculations, the best point of the shielding space around the center of symmetric or non-symmetric aromatic molecules can evaluated as an aromaticity criterion. and in this method the expectation of the (η*) and (κ*)have been calculated as the Gaussian curve functions versus one , two  or three dimensional distances around the center of the SiO2 (Tables 1-4and Fig.1-7).

The isotropy (σiso*) which is related to all of (η*) and (κ *)and (Ω*) and ( *) is the best criterion for various aromatic molecules by the S-NICS method, which can express both qualitative and quantitative magnitudes for symmetric or non-symmetric aromatic molecules (table 3).

So “κ” can be calculated in two ways, the first one by the expectation value of the Gaussian curve (κ*) and the second one with the eqs. (27,28). Such as stochastic rules in the Monte Carlo calculation for π = 3.14 in a circle,it is evident, that the value of the Monte Carlo calculation will be more accurate by increasing the random numbers of the stochastic test, and it is significant that |κ*- κ |→0.0 by addition of random numbers in the S-NICS method.

Similar to the NICS method, in S-NICS, negative nucleus-independent chemical shifts denote aromaticity and positive values denote antiaromaticity.In S-NICS methods, the shielding and deshielding spaces are significant to discuss the mechanism of the aromatic molecules in point of ring currents, which are the circulating π electrons in an aromatic molecule produce opposite to the applied magnetics field.

The stability of the isotropy criterion is highly affectedon the best places in the shielding area spaces and it is dependent on the structures of the aromatic rings. Soby using this method, a suitable and stable magnitude of isotropy can calculated as an aromaticity criterion. It is obvious that structural factors cause changes in the magnetic field experienced by the nuclei and change the resonant frequency.Therefore the chemical shielding and many other factors such as electronegativity,hydrogen bonding, and magnetic anisotropy of π-systems will be changed because of the electrons around the proton which produce a magnetic field, countering the applied field. This reduces the field experienced at the nucleus.The electrons are said to shield the proton, an effect that is exactly dependent on the distance of the center. In addition, S-NICS can find the most accurate places for effective points for calculation of isotropy as an aromaticity criterion. The chemical shielding is a vector orientation function for all of the shielding parameters that can change in various places inside the shielding area of the rings for aromatic compounds.

The asymmetric (η),skew(k)parameters have frequent changing or fluctuatingvalues which have been modeled by a Gaussian distribution. And the shielding space around the center of benzene, naphthalene and borazine are canonical , where the (+) denotes the shielding and (–) indicates deshielding areas, and anisotropy as an orientation function has a fluctuating behavior and their values have been changed statistically in a Gaussian distribution.

On the other hand, the nearby protons will experience three fields:  the applied field, the shielding field of the valence electrons and the field due to the π systems. So field lines opposed to the applied field cause a reduced field in this area equivalent to shielding, anisotropic induced magnetic field lines due to the induced circulation of the π electron in the ring area of benzene, naphthalene and borazine.S-NICS hasbeen investigated by the Monte Carlo model by computation of nucleus-independent chemical shifts in many points of shielding areas around the rings of borazine, benzene and naphthalene, by choosing specified and suitable distances (Scheme 3).The statistical simulation by the Monte Carlo method is the generation of pseudo-random numbers that are distributed in a Gaussian distribution, and the algorithm is based on a pseudorandom number generator that produces numbers x that are uniformly distributed in the interval [0, 1).

These random varietiesx are then transformed via some algorithm to create a new random variate having the required probability distribution, (Tables 1, 2). The asymmetry (η), and skew (κ) parameters fluctuate by the changing of tensors, while in the case of an axially symmetric tensor, σ22 equals either σ11 or σ33 and a = Ω/3, the span is κ= ±1 by changing asymmetry between 0 ≤ η ≤ +1.

 Scheme1: (a) Some optimized isomers of B3N3, and their point groups, (aˊ ) some optimized isomers of B4N4, and their point groups, in both of them, the rings with alternation of B and N are more stable and the arrangements of stability are shown. (b) The sphere region of S-NICS in optimized structures of B12N12, B15N15 and B18N18 Rings .all molecules are optimized with B3LYP/EPR-II level.(C)The sphere region of S-NICS in optimized structures ofSi18O27

Scheme1: (a) Some optimized isomers of B3N3, and their point groups, (aˊ ) some optimized isomers of B4N4, and their point groups, in both of them, the rings with alternation of B and N are more stable and the arrangements of stability are shown. (b) The sphere region of S-NICS in optimized structures of B12N12, B15N15 and B18N18 Rings .all molecules are optimized with B3LYP/EPR-II level.(C)The sphere region of S-NICS in optimized structures ofSi18O27


Click here to View Scheme

 

 

Table 1: The NMR Parameters for BQ=0/09(3)

B3LYP/6-31G    NMR=GIAO       0/09(3)

atom

σ11

σ22

σ33

∆σ

ƞ

σ0iso(2)

σ±2sym(2)

Span(Ω)

ƙ

σiso

ζzz

1

-956.9445

1083.4728

7532.725

7469.4609

0.4097519

6098.5658

2489.8203

8489.6695

0.5193176

2553.0844

4979.6406

2

-3374.1985

848.4266

5337.8656

6600.7516

0.9595783

5389.2937

2200.2506

8712.0641

0.0306258

937.36457

4400.5011

3

178.9333

744.1915

3142.4491

2680.8867

0.3162712

2188.8546

893.6289

2963.5158

0.6185219

1355.1913

1787.2578

4

-1183.6157

-469.2794

6653.7304

7480.178

0.1432459

6107.316

2493.3927

7837.3461

0.8177096

1666.9451

4986.7853

5

110.992

975.0664

12561.8095

12018.78

0.1078405

9812.9335

4006.2601

12450.818

0.861202

4549.2893

8012.5202

6

-367.8772

16.3726

2243.4669

2419.2192

0.2382482

1975.2118

806.4064

2611.3441

0.7057073

630.6541

1612.8128

7

-2763.2793

159.7606

5052.1679

6353.9273

0.6900551

5187.7698

2117.9758

7815.4472

0.251984

816.2164

4235.9515

8

-6289.8512

187.4013

2580.0565

5631.2815

1.7253406

4597.7536

1877.0938

8869.9077

-0.460501

-1174.131

3754.1876

9

-2148.2802

477.4417

2876.8497

3712.269

1.0609638

3030.9439

1237.423

5025.1299

-0.045036

402.00373

2474.846

10

-6512.5485

7.9388

2252.0367

5504.3416

1.7769121

4494.1115

1834.7806

8764.5852

-0.487917

-1417.524

3669.5611

11

-42.9918

220.3325

4828.4089

4739.7386

0.0833351

3869.8385

1579.9129

4871.4007

0.8918897

1668.5832

3159.8257

12

-4147.0372

-106.0939

4209.0304

6335.596

0.9567237

5172.8029

2111.8653

8356.0676

0.0328122

-14.70023

4223.7306

13

117.3647

419.4482

8906.534

8638.1276

0.0524564

7052.7432

2879.3759

8789.1693

0.9312601

3147.7823

5758.7517

14

-794.9836

459.2989

1653.8328

1821.6752

1.0327987

1487.337

607.22505

2448.8164

-0.024399

439.3827

1214.4501

15

-1318.8868

852.2523

8128.2713

8361.5886

0.3894844

6826.9584

2787.1962

9447.1581

0.5403614

2553.8789

5574.3924

16

-4035.1798

216.586

3860.1255

5769.4224

1.1054224

4710.5411

1923.1408

7895.3053

-0.077036

13.8439

3846.2816

17

-3007.5149

557.9322

1705.0616

2929.853

1.8254058

2392.1273

976.61765

4712.5765

-0.513163

-248.1737

1953.2353

18

-2652.2661

200.5141

3365.2841

4591.1601

0.9320455

3748.5292

1530.3867

6017.5502

0.0518466

304.5107

3060.7734

19

-1172.0822

1262.6031

7679.6091

7634.3487

0.478368

6233.1912

2544.7829

8851.6913

0.4498938

2590.0433

5089.5658

20

-844.0735

1466.732

7313.6022

7002.273

0.4950119

5717.1225

2334.091

8157.6757

0.4334647

2645.4202

4668.182

21

-132.9882

742.4337

2027.6005

1722.8778

0.7621741

1406.6723

574.2926

2160.5887

0.189645

879.01533

1148.5852

22

134.332

752.8564

2813.5901

2369.9959

0.3914718

1935.0227

789.99865

2679.2581

0.5382868

1233.5928

1579.9973

23

-1619.9856

1199.4706

5526.3823

5736.6398

0.7372233

4683.7751

1912.2133

7146.3679

0.2109401

1701.9558

3824.4265

24

-347.6019

1091.5889

10841.9332

10469.94

0.206189

8548.3568

3489.9799

11189.535

0.7427613

3861.9734

6979.9598

25

66.743

1106.2361

10142.7306

9556.2411

0.1631645

7802.3523

3185.4137

10075.988

0.7936692

3771.9032

6370.8274

26

-1552.0935

1098.0741

6058.0436

6285.0533

0.6324929

5131.5365

2095.0178

7610.1371

0.3035165

1868.0081

4190.0355

27

-4379.5365

5.4372

3699.8494

5886.8991

1.1173048

4806.4569

1962.2997

8079.3859

-0.085472

-224.75

3924.5994

28

-4706.3136

297.386

6313.2225

8517.6863

0.8811723

6954.4069

2839.2288

11019.536

0.0918493

634.76497

5678.4575

29

-5750.8297

150.5728

5251.3484

8051.4769

1.0994385

6573.7624

2683.8256

11002.178

-0.07277

-116.3028

5367.6512

30

-3377.6973

68.9263

1923.1441

3577.5296

1.4451132

2920.9336

1192.5099

5300.8414

-0.300406

-461.8756

2385.0197

31

-2529.0503

415.9993

2861.8965

3918.422

1.1273861

3199.2609

1306.1407

5390.9468

-0.092591

249.61517

2612.2813

32

-13313.7769

236.7772

6478.223

13016.723

1.5615168

10627.72

4338.9076

19792

-0.369296

-2199.592

8677.8152

33

-342.1912

-59.7532

3910.972

4111.9442

0.1030308

3357.2653

1370.6481

4253.1632

0.8671869

1169.6759

2741.2961

34

105.1833

260.4736

4135.8266

3952.9982

0.0589263

3227.4912

1317.6661

4030.6433

0.9229452

1500.4945

2635.3321

35

-8181.1451

-77.0719

2897.3435

7026.452

1.7300495

5736.8638

2342.1507

11078.489

-0.463029

-1786.958

4684.3013

36

-122.1222

-6.8953

7541.5657

7606.0745

0.022724

6210.1063

2535.3582

7663.6879

0.9699291

2470.8494

5070.7163

37

73.7637

445.2708

8317.0012

8057.484

0.0691606

6578.6671

2685.828

8243.2375

0.9098638

2945.3452

5371.656

38

-2371.0975

638.6244

6844.6029

7710.8395

0.5854853

6295.6433

2570.2798

9215.7004

0.3468273

1704.0433

5140.5596

39

-1705.6132

815.6228

7552.004

7996.9992

0.4729091

6529.2833

2665.6664

9257.6172

0.4553164

2220.6712

5331.3328

40

-3476.9414

273.655

867.2673

2468.9105

2.2786952

2015.7831

822.97015

4344.2087

-0.726711

-778.673

1645.9403

41

-3289.9488

414.833

1998.3208

3435.8787

1.6173949

2805.2804

1145.2929

5288.2696

-0.401132

-292.265

2290.5858

42

-1793.8273

-205.034

2362.3919

3361.8226

0.7088982

2744.816

1120.6075

4156.2192

0.2354622

121.17687

2241.215

43

-4159.9595

141.0963

6540.979

8550.4106

0.754535

6981.1253

2850.1369

10700.939

0.1961348

840.70527

5700.2738

44

-5750.4931

236.0481

5858.1423

8615.3648

1.042302

7034.1581

2871.7883

11608.635

-0.031394

114.56577

5743.5765

45

-11729.9838

133.1489

9979.1707

15777.588

1.1278466

12881.875

5259.1961

21709.155

-0.092915

-539.2214

10518.392

46

-1.2686

0.3899

60.9549

61.39425

0.0405209

50.126359

20.46475

62.2235

0.9466922

20.0254

40.9295

 

Table 2: The NMR Parameters for BQ=0.1(1)

B3LYP/6-31G    NMR=GIAO       0/1(1)

 atom

σ11

σ22

σ33

∆σ

ƞ

σ0iso(2)

σ±2sym(2)

Span(Ω)

ƙ

σiso

ζzz

1

-956.9445

1083.4728

7532.725

7469.4609

0.4097519

6098.5658

2489.8203

8489.6695

0.5193176

2553.0844

4979.6406

2

-3374.1985

848.4266

5337.8656

6600.7516

0.9595783

5389.2937

2200.2506

8712.0641

0.0306258

937.36457

4400.5011

3

178.9333

744.1915

3142.4491

2680.8867

0.3162712

2188.8546

893.6289

2963.5158

0.6185219

1355.1913

1787.2578

4

-1183.6157

-469.2794

6653.7304

7480.178

0.1432459

6107.316

2493.3927

7837.3461

0.8177096

1666.9451

4986.7853

5

110.992

975.0664

12561.8095

12018.78

0.1078405

9812.9335

4006.2601

12450.818

0.861202

4549.2893

8012.5202

6

-367.8772

16.3726

2243.4669

2419.2192

0.2382482

1975.2118

806.4064

2611.3441

0.7057073

630.6541

1612.8128

7

-2763.2793

159.7606

5052.1679

6353.9273

0.6900551

5187.7698

2117.9758

7815.4472

0.251984

816.2164

4235.9515

8

-6289.8512

187.4013

2580.0565

5631.2815

1.7253406

4597.7536

1877.0938

8869.9077

-0.460501

-1174.131

3754.1876

9

-2148.2802

477.4417

2876.8497

3712.269

1.0609638

3030.9439

1237.423

5025.1299

-0.045036

402.00373

2474.846

10

-6512.5485

7.9388

2252.0367

5504.3416

1.7769121

4494.1115

1834.7806

8764.5852

-0.487917

-1417.524

3669.5611

11

-42.9918

220.3325

4828.4089

4739.7386

0.0833351

3869.8385

1579.9129

4871.4007

0.8918897

1668.5832

3159.8257

12

-4147.0372

-106.0939

4209.0304

6335.596

0.9567237

5172.8029

2111.8653

8356.0676

0.0328122

-14.70023

4223.7306

13

117.3647

419.4482

8906.534

8638.1276

0.0524564

7052.7432

2879.3759

8789.1693

0.9312601

3147.7823

5758.7517

14

-794.9836

459.2989

1653.8328

1821.6752

1.0327987

1487.337

607.22505

2448.8164

-0.024399

439.3827

1214.4501

15

-1318.8868

852.2523

8128.2713

8361.5886

0.3894844

6826.9584

2787.1962

9447.1581

0.5403614

2553.8789

5574.3924

16

-4035.1798

216.586

3860.1255

5769.4224

1.1054224

4710.5411

1923.1408

7895.3053

-0.077036

13.8439

3846.2816

17

-3007.5149

557.9322

1705.0616

2929.853

1.8254058

2392.1273

976.61765

4712.5765

-0.513163

-248.1737

1953.2353

18

-2652.2661

200.5141

3365.2841

4591.1601

0.9320455

3748.5292

1530.3867

6017.5502

0.0518466

304.5107

3060.7734

19

-1172.0822

1262.6031

7679.6091

7634.3487

0.478368

6233.1912

2544.7829

8851.6913

0.4498938

2590.0433

5089.5658

20

-844.0735

1466.732

7313.6022

7002.273

0.4950119

5717.1225

2334.091

8157.6757

0.4334647

2645.4202

4668.182

21

-132.9882

742.4337

2027.6005

1722.8778

0.7621741

1406.6723

574.2926

2160.5887

0.189645

879.01533

1148.5852

22

134.332

752.8564

2813.5901

2369.9959

0.3914718

1935.0227

789.99865

2679.2581

0.5382868

1233.5928

1579.9973

23

-1619.9856

1199.4706

5526.3823

5736.6398

0.7372233

4683.7751

1912.2133

7146.3679

0.2109401

1701.9558

3824.4265

24

-347.6019

1091.5889

10841.9332

10469.94

0.206189

8548.3568

3489.9799

11189.535

0.7427613

3861.9734

6979.9598

25

66.743

1106.2361

10142.7306

9556.2411

0.1631645

7802.3523

3185.4137

10075.988

0.7936692

3771.9032

6370.8274

26

-1552.0935

1098.0741

6058.0436

6285.0533

0.6324929

5131.5365

2095.0178

7610.1371

0.3035165

1868.0081

4190.0355

27

-4379.5365

5.4372

3699.8494

5886.8991

1.1173048

4806.4569

1962.2997

8079.3859

-0.085472

-224.75

3924.5994

28

-4706.3136

297.386

6313.2225

8517.6863

0.8811723

6954.4069

2839.2288

11019.536

0.0918493

634.76497

5678.4575

29

-5750.8297

150.5728

5251.3484

8051.4769

1.0994385

6573.7624

2683.8256

11002.178

-0.07277

-116.3028

5367.6512

30

-3377.6973

68.9263

1923.1441

3577.5296

1.4451132

2920.9336

1192.5099

5300.8414

-0.300406

-461.8756

2385.0197

31

-2529.0503

415.9993

2861.8965

3918.422

1.1273861

3199.2609

1306.1407

5390.9468

-0.092591

249.61517

2612.2813

32

-13313.7769

236.7772

6478.223

13016.723

1.5615168

10627.72

4338.9076

19792

-0.369296

-2199.592

8677.8152

33

-342.1912

-59.7532

3910.972

4111.9442

0.1030308

3357.2653

1370.6481

4253.1632

0.8671869

1169.6759

2741.2961

34

105.1833

260.4736

4135.8266

3952.9982

0.0589263

3227.4912

1317.6661

4030.6433

0.9229452

1500.4945

2635.3321

35

-8181.1451

-77.0719

2897.3435

7026.452

1.7300495

5736.8638

2342.1507

11078.489

-0.463029

-1786.958

4684.3013

36

-122.1222

-6.8953

7541.5657

7606.0745

0.022724

6210.1063

2535.3582

7663.6879

0.9699291

2470.8494

5070.7163

37

73.7637

445.2708

8317.0012

8057.484

0.0691606

6578.6671

2685.828

8243.2375

0.9098638

2945.3452

5371.656

38

-2371.0975

638.6244

6844.6029

7710.8395

0.5854853

6295.6433

2570.2798

9215.7004

0.3468273

1704.0433

5140.5596

39

-1705.6132

815.6228

7552.004

7996.9992

0.4729091

6529.2833

2665.6664

9257.6172

0.4553164

2220.6712

5331.3328

40

-3476.9414

273.655

867.2673

2468.9105

2.2786952

2015.7831

822.97015

4344.2087

-0.726711

-778.673

1645.9403

41

-3289.9488

414.833

1998.3208

3435.8787

1.6173949

2805.2804

1145.2929

5288.2696

-0.401132

-292.265

2290.5858

42

-1793.8273

-205.034

2362.3919

3361.8226

0.7088982

2744.816

1120.6075

4156.2192

0.2354622

121.17687

2241.215

43

-4159.9595

141.0963

6540.979

8550.4106

0.754535

6981.1253

2850.1369

10700.939

0.1961348

840.70527

5700.2738

44

-5750.4931

236.0481

5858.1423

8615.3648

1.042302

7034.1581

2871.7883

11608.635

-0.031394

114.56577

5743.5765

45

-11729.9838

133.1489

9979.1707

15777.588

1.1278466

12881.875

5259.1961

21709.155

-0.092915

-539.2214

10518.392

 

Table 3: The NMR Parameter for BQ=0/1(2)

B3LYP/6-31G    NMR=GIAO       0/1(2)

 atom

σ11

σ22

σ33

∆σ

ƞ

σ0iso(2)

σ±sym(2)

Span(Ω)

ƙ

σiso

ζzz

1

-956.9445

1083.4728

7532.725

7469.4609

0.4097519

6098.5658

2489.8203

8489.6695

0.5193176

2553.0844

4979.6406

2

-3374.1985

848.4266

5337.8656

6600.7516

0.9595783

5389.2937

2200.2506

8712.0641

0.0306258

937.36457

4400.5011

3

178.9333

744.1915

3142.4491

2680.8867

0.3162712

2188.8546

893.6289

2963.5158

0.6185219

1355.1913

1787.2578

4

-1183.6157

-469.2794

6653.7304

7480.178

0.1432459

6107.316

2493.3927

7837.3461

0.8177096

1666.9451

4986.7853

5

110.992

975.0664

12561.8095

12018.78

0.1078405

9812.9335

4006.2601

12450.818

0.861202

4549.2893

8012.5202

6

-367.8772

16.3726

2243.4669

2419.2192

0.2382482

1975.2118

806.4064

2611.3441

0.7057073

630.6541

1612.8128

7

-2763.2793

159.7606

5052.1679

6353.9273

0.6900551

5187.7698

2117.9758

7815.4472

0.251984

816.2164

4235.9515

8

-6289.8512

187.4013

2580.0565

5631.2815

1.7253406

4597.7536

1877.0938

8869.9077

-0.460501

-1174.131

3754.1876

9

-2148.2802

477.4417

2876.8497

3712.269

1.0609638

3030.9439

1237.423

5025.1299

-0.045036

402.00373

2474.846

10

-6512.5485

7.9388

2252.0367

5504.3416

1.7769121

4494.1115

1834.7806

8764.5852

-0.487917

-1417.524

3669.5611

11

-42.9918

220.3325

4828.4089

4739.7386

0.0833351

3869.8385

1579.9129

4871.4007

0.8918897

1668.5832

3159.8257

12

-4147.0372

-106.0939

4209.0304

6335.596

0.9567237

5172.8029

2111.8653

8356.0676

0.0328122

-14.70023

4223.7306

13

117.3647

419.4482

8906.534

8638.1276

0.0524564

7052.7432

2879.3759

8789.1693

0.9312601

3147.7823

5758.7517

14

-794.9836

459.2989

1653.8328

1821.6752

1.0327987

1487.337

607.22505

2448.8164

-0.024399

439.3827

1214.4501

15

-1318.8868

852.2523

8128.2713

8361.5886

0.3894844

6826.9584

2787.1962

9447.1581

0.5403614

2553.8789

5574.3924

16

-4035.1798

216.586

3860.1255

5769.4224

1.1054224

4710.5411

1923.1408

7895.3053

-0.077036

13.8439

3846.2816

17

-3007.5149

557.9322

1705.0616

2929.853

1.8254058

2392.1273

976.61765

4712.5765

-0.513163

-248.1737

1953.2353

18

-2652.2661

200.5141

3365.2841

4591.1601

0.9320455

3748.5292

1530.3867

6017.5502

0.0518466

304.5107

3060.7734

19

-1172.0822

1262.6031

7679.6091

7634.3487

0.478368

6233.1912

2544.7829

8851.6913

0.4498938

2590.0433

5089.5658

20

-844.0735

1466.732

7313.6022

7002.273

0.4950119

5717.1225

2334.091

8157.6757

0.4334647

2645.4202

4668.182

21

-132.9882

742.4337

2027.6005

1722.8778

0.7621741

1406.6723

574.2926

2160.5887

0.189645

879.01533

1148.5852

22

134.332

752.8564

2813.5901

2369.9959

0.3914718

1935.0227

789.99865

2679.2581

0.5382868

1233.5928

1579.9973

23

-1619.9856

1199.4706

5526.3823

5736.6398

0.7372233

4683.7751

1912.2133

7146.3679

0.2109401

1701.9558

3824.4265

24

-347.6019

1091.5889

10841.9332

10469.94

0.206189

8548.3568

3489.9799

11189.535

0.7427613

3861.9734

6979.9598

25

66.743

1106.2361

10142.7306

9556.2411

0.1631645

7802.3523

3185.4137

10075.988

0.7936692

3771.9032

6370.8274

26

-1552.0935

1098.0741

6058.0436

6285.0533

0.6324929

5131.5365

2095.0178

7610.1371

0.3035165

1868.0081

4190.0355

27

-4379.5365

5.4372

3699.8494

5886.8991

1.1173048

4806.4569

1962.2997

8079.3859

-0.085472

-224.75

3924.5994

28

-4706.3136

297.386

6313.2225

8517.6863

0.8811723

6954.4069

2839.2288

11019.536

0.0918493

634.76497

5678.4575

29

-5750.8297

150.5728

5251.3484

8051.4769

1.0994385

6573.7624

2683.8256

11002.178

-0.07277

-116.3028

5367.6512

30

-3377.6973

68.9263

1923.1441

3577.5296

1.4451132

2920.9336

1192.5099

5300.8414

-0.300406

-461.8756

2385.0197

31

-2529.0503

415.9993

2861.8965

3918.422

1.1273861

3199.2609

1306.1407

5390.9468

-0.092591

249.61517

2612.2813

32

-13313.7769

236.7772

6478.223

13016.723

1.5615168

10627.72

4338.9076

19792

-0.369296

-2199.592

8677.8152

33

-342.1912

-59.7532

3910.972

4111.9442

0.1030308

3357.2653

1370.6481

4253.1632

0.8671869

1169.6759

2741.2961

34

105.1833

260.4736

4135.8266

3952.9982

0.0589263

3227.4912

1317.6661

4030.6433

0.9229452

1500.4945

2635.3321

35

-8181.1451

-77.0719

2897.3435

7026.452

1.7300495

5736.8638

2342.1507

11078.489

-0.463029

-1786.958

4684.3013

36

-122.1222

-6.8953

7541.5657

7606.0745

0.022724

6210.1063

2535.3582

7663.6879

0.9699291

2470.8494

5070.7163

37

73.7637

445.2708

8317.0012

8057.484

0.0691606

6578.6671

2685.828

8243.2375

0.9098638

2945.3452

5371.656

38

-2371.0975

638.6244

6844.6029

7710.8395

0.5854853

6295.6433

2570.2798

9215.7004

0.3468273

1704.0433

5140.5596

39

-1705.6132

815.6228

7552.004

7996.9992

0.4729091

6529.2833

2665.6664

9257.6172

0.4553164

2220.6712

5331.3328

40

-3476.9414

273.655

867.2673

2468.9105

2.2786952

2015.7831

822.97015

4344.2087

-0.726711

-778.673

1645.9403

41

-3289.9488

414.833

1998.3208

3435.8787

1.6173949

2805.2804

1145.2929

5288.2696

-0.401132

-292.265

2290.5858

42

-1793.8273

-205.034

2362.3919

3361.8226

0.7088982

2744.816

1120.6075

4156.2192

0.2354622

121.17687

2241.215

43

-4159.9595

141.0963

6540.979

8550.4106

0.754535

6981.1253

2850.1369

10700.939

0.1961348

840.70527

5700.2738

44

-5750.4931

236.0481

5858.1423

8615.3648

1.042302

7034.1581

2871.7883

11608.635

-0.031394

114.56577

5743.5765

45

-11729.9838

133.1489

9979.1707

15777.588

1.1278466

12881.875

5259.1961

21709.155

-0.092915

-539.2214

10518.392

46

-1.4025

0.303

60.591

61.14075

0.041842

49.919384

20.38025

61.9935

0.9449781

19.8305

40.7605

 

Table 4: The NMR Parameter for BQ=0/1(3)

B3LYP/6-31G    NMR=GIAO       0/1(3)

 

σ11

σ22

σ33

∆σ

ƞ

σ0iso(2)

σ±sym(2)

Span(Ω)

ƙ

σiso

ζzz

1

-956.9445

1083.4728

7532.725

7469.4609

0.4097519

6098.5658

2489.8203

8489.6695

0.5193176

2553.0844

4979.6406

2

-3374.1985

848.4266

5337.8656

6600.7516

0.9595783

5389.2937

2200.2506

8712.0641

0.0306258

937.36457

4400.5011

3

178.9333

744.1915

3142.4491

2680.8867

0.3162712

2188.8546

893.6289

2963.5158

0.6185219

1355.1913

1787.2578

4

-1183.6157

-469.2794

6653.7304

7480.178

0.1432459

6107.316

2493.3927

7837.3461

0.8177096

1666.9451

4986.7853

5

110.992

975.0664

12561.8095

12018.78

0.1078405

9812.9335

4006.2601

12450.818

0.861202

4549.2893

8012.5202

6

-367.8772

16.3726

2243.4669

2419.2192

0.2382482

1975.2118

806.4064

2611.3441

0.7057073

630.6541

1612.8128

7

-2763.2793

159.7606

5052.1679

6353.9273

0.6900551

5187.7698

2117.9758

7815.4472

0.251984

816.2164

4235.9515

8

-6289.8512

187.4013

2580.0565

5631.2815

1.7253406

4597.7536

1877.0938

8869.9077

-0.460501

-1174.131

3754.1876

9

-2148.2802

477.4417

2876.8497

3712.269

1.0609638

3030.9439

1237.423

5025.1299

-0.045036

402.00373

2474.846

10

-6512.5485

7.9388

2252.0367

5504.3416

1.7769121

4494.1115

1834.7806

8764.5852

-0.487917

-1417.524

3669.5611

11

-42.9918

220.3325

4828.4089

4739.7386

0.0833351

3869.8385

1579.9129

4871.4007

0.8918897

1668.5832

3159.8257

12

-4147.0372

-106.0939

4209.0304

6335.596

0.9567237

5172.8029

2111.8653

8356.0676

0.0328122

-14.70023

4223.7306

13

117.3647

419.4482

8906.534

8638.1276

0.0524564

7052.7432

2879.3759

8789.1693

0.9312601

3147.7823

5758.7517

14

-794.9836

459.2989

1653.8328

1821.6752

1.0327987

1487.337

607.22505

2448.8164

-0.024399

439.3827

1214.4501

15

-1318.8868

852.2523

8128.2713

8361.5886

0.3894844

6826.9584

2787.1962

9447.1581

0.5403614

2553.8789

5574.3924

16

-4035.1798

216.586

3860.1255

5769.4224

1.1054224

4710.5411

1923.1408

7895.3053

-0.077036

13.8439

3846.2816

17

-3007.5149

557.9322

1705.0616

2929.853

1.8254058

2392.1273

976.61765

4712.5765

-0.513163

-248.1737

1953.2353

18

-2652.2661

200.5141

3365.2841

4591.1601

0.9320455

3748.5292

1530.3867

6017.5502

0.0518466

304.5107

3060.7734

19

-1172.0822

1262.6031

7679.6091

7634.3487

0.478368

6233.1912

2544.7829

8851.6913

0.4498938

2590.0433

5089.5658

20

-844.0735

1466.732

7313.6022

7002.273

0.4950119

5717.1225

2334.091

8157.6757

0.4334647

2645.4202

4668.182

21

-132.9882

742.4337

2027.6005

1722.8778

0.7621741

1406.6723

574.2926

2160.5887

0.189645

879.01533

1148.5852

22

134.332

752.8564

2813.5901

2369.9959

0.3914718

1935.0227

789.99865

2679.2581

0.5382868

1233.5928

1579.9973

23

-1619.9856

1199.4706

5526.3823

5736.6398

0.7372233

4683.7751

1912.2133

7146.3679

0.2109401

1701.9558

3824.4265

24

-347.6019

1091.5889

10841.9332

10469.94

0.206189

8548.3568

3489.9799

11189.535

0.7427613

3861.9734

6979.9598

25

66.743

1106.2361

10142.7306

9556.2411

0.1631645

7802.3523

3185.4137

10075.988

0.7936692

3771.9032

6370.8274

26

-1552.0935

1098.0741

6058.0436

6285.0533

0.6324929

5131.5365

2095.0178

7610.1371

0.3035165

1868.0081

4190.0355

27

-4379.5365

5.4372

3699.8494

5886.8991

1.1173048

4806.4569

1962.2997

8079.3859

-0.085472

-224.75

3924.5994

28

-4706.3136

297.386

6313.2225

8517.6863

0.8811723

6954.4069

2839.2288

11019.536

0.0918493

634.76497

5678.4575

29

-5750.8297

150.5728

5251.3484

8051.4769

1.0994385

6573.7624

2683.8256

11002.178

-0.07277

-116.3028

5367.6512

30

-3377.6973

68.9263

1923.1441

3577.5296

1.4451132

2920.9336

1192.5099

5300.8414

-0.300406

-461.8756

2385.0197

31

-2529.0503

415.9993

2861.8965

3918.422

1.1273861

3199.2609

1306.1407

5390.9468

-0.092591

249.61517

2612.2813

32

-13313.7769

236.7772

6478.223

13016.723

1.5615168

10627.72

4338.9076

19792

-0.369296

-2199.592

8677.8152

33

-342.1912

-59.7532

3910.972

4111.9442

0.1030308

3357.2653

1370.6481

4253.1632

0.8671869

1169.6759

2741.2961

34

105.1833

260.4736

4135.8266

3952.9982

0.0589263

3227.4912

1317.6661

4030.6433

0.9229452

1500.4945

2635.3321

35

-8181.1451

-77.0719

2897.3435

7026.452

1.7300495

5736.8638

2342.1507

11078.489

-0.463029

-1786.958

4684.3013

36

-122.1222

-6.8953

7541.5657

7606.0745

0.022724

6210.1063

2535.3582

7663.6879

0.9699291

2470.8494

5070.7163

37

73.7637

445.2708

8317.0012

8057.484

0.0691606

6578.6671

2685.828

8243.2375

0.9098638

2945.3452

5371.656

38

-2371.0975

638.6244

6844.6029

7710.8395

0.5854853

6295.6433

2570.2798

9215.7004

0.3468273

1704.0433

5140.5596

39

-1705.6132

815.6228

7552.004

7996.9992

0.4729091

6529.2833

2665.6664

9257.6172

0.4553164

2220.6712

5331.3328

40

-3476.9414

273.655

867.2673

2468.9105

2.2786952

2015.7831

822.97015

4344.2087

-0.726711

-778.673

1645.9403

41

-3289.9488

414.833

1998.3208

3435.8787

1.6173949

2805.2804

1145.2929

5288.2696

-0.401132

-292.265

2290.5858

42

-1793.8273

-205.034

2362.3919

3361.8226

0.7088982

2744.816

1120.6075

4156.2192

0.2354622

121.17687

2241.215

43

-4159.9595

141.0963

6540.979

8550.4106

0.754535

6981.1253

2850.1369

10700.939

0.1961348

840.70527

5700.2738

44

-5750.4931

236.0481

5858.1423

8615.3648

1.042302

7034.1581

2871.7883

11608.635

-0.031394

114.56577

5743.5765

45

-11729.9838

133.1489

9979.1707

15777.588

1.1278466

12881.875

5259.1961

21709.155

-0.092915

-539.2214

10518.392

46

-1.2697

0.3822

60.9302

61.37395

0.040373

50.109825

20.458

62.1999

0.9468826

20.014233

40.916

 

Figure 1: NMR Parameter (ppm) of span, Iso and Aniso versus atomic number

Figure 1: NMR Parameter (ppm) of span, Iso and Aniso versus atomic number


Click here to View Figure

Figure 2: NMR Parameter versus atomic number for Giao and BQ=0.03

Figure 2: NMR Parameter versus atomic number for Giao and BQ=0.03


Click here to View Figure

Figure 3: NMR Parameter verses atomic number for BQ=0.1

Figure 3: NMR Parameter verses atomic number for BQ=0.1


Click here to View Figure

Figure 4: NMR Versus atomic number for iso and ZZ in GIAO methods and BQ=0.1

Figure 4: NMR Versus atomic number for iso and ZZ in GIAO methods and BQ=0.1


Click here to View Figure

Figure 5: NMR Parameter versus atomic number  for Span

Figure 5: NMR Parameter versus atomic number  for Span


Click here to View Figure

Figure 6: For BQ=).1(2)

Figure 6: For BQ=).1(2)


Click here to View Figure

Figure 7: ppm of NMR data versus atomic number

Figure 7: ppm of NMR data versus atomic number


Click here to View Figure

Figure 8: ZigmaIso for the Giao=0.1(3) Figure 8: ZigmaIso for the Giao=0.1(3) 

Click here to View Figure

 

References

  1. Minkin, V. J. ;Glukhovtsev, M. N. ;Simkin, B.Y. ;Electronic and Structural Aspects, Wiley, New York, 1984.
  2. Mason, J. ;Solid State Nucl.Magn.Reson.1993,2, 285.
  3. Schleyer, P. v. R. ; Jiao, H. ; van EikemaHommes, N. J. R. ;Malkin, V. G. ;Malkina, O. L. ; J. Am. Chem. Soc. 1997, 119, 12669.
  4. Schleyer, P. v. R. ;Maerker, C. ;Dransfeld, A. ; Jiao, H. ; van EikemaHommes, N. J. R.  J. Am. Chem.Soc.1996,118, 6317.
  5. Schleyer, P. v. R. ; Jiao, H. ;Pure. Appl. Chem.1996, 68, 209.
  6. Kruszewski, J .; Krygowski, T. M. ;Tetrahedron Letters,1972,36, 3839.
  7. Stepien, B.T. ;Krygowski, T.M. ;Cyranski, M.K. ;Mlochowski, J.;Orioli, P. ;Abbate, F.  ARKIVOC,2004, 3,185.
  8. Katritzky, A. R. ; Barczynski, P.;Musumarra, G. ; Pisano, D. ;Szafran, M.  J. Am. Chem.Soc.1989, 111, 7.
  9. Feixas, F. ;Matito, E. ;Poater, J. ;Solà, M.  Journal of Computational Chemistry.2008, 29, 543.
  10. Katritzky, A. R.;Karelson,  M.;Sild, S.;Krygowski, T. M.;  Jug. K.  J. Org. Chem.1998,63, 5228.
  11. Fias, S.; Van Damme, S.; Bultinck,P.; Journal of Computational Chemistry. 2008,29, 358.
  12. Hehre, W. J.  R.;Ditchfield, Radom, L.;Pople, J. A.  J. Am. Chem. Soc.1970, 92, 4796.
  13. Cooper, D. L.;Gerratt, J.;  Raimondi, M.  Nature,1986,323, 699.
  14. Julg, A. Francois, Ph.;Theor. Chim.Acta.1967,7, 249.
  15. Monajjemi, M.;Struct. Chem.2012,23, 551.
  16. Monajjemi, M.; Lee, V. S.;Khaleghian, M.;Honarparvar, B.;Mollaamin. F.;J. Phys. Chem. C.2010114, 15315.
  17. Monajjemi, M.;Khaleghian, M.;J. Cluster Sci.2011, 22, 673.
  18. Monajjemi, M.; Boggs, J.E, J. Phys. Chem. A,20133.
  19. Frueh, D.;Nucl.P.;Reson.M,Spectrosc.2002,41, 305.
  20. Jiao, H.;  .Schleyer, P. v. R,J. Am. Chem. Soc. 1995,117, 11529.
  21. Martin, N. H.; Nance, K.H.;Journal of Molecular Graphics and Modelling.2002,21, 51.
  22. Luginbhl, P.;Wuthrich , K.;Progress in Nuclear Magnetic Resonance Spectroscopy.2002, 40, 199.
  23. Magn. R. L.;Reson. Rev.1987,12, 91.
  24. Monajjemi,M.; Mohammadian,T.N.; J. Comput. Theor.Nanosci.2015, 12, 4895-4914.
  25. Greenwood, Norman N.; Earnshaw, Alan Chemistry of the Elements (2nd ed.). Butterworth-Heinemann.(1997). ISBN 0080379419.
  26. Laurent, S.; Forge, D.; Port, M.; Roch, A.; Robic, C.; Vander Elst, L.; Muller, R.N. Chem. Rev. 2008, 108, 2064–2110.
  27. Kodama, R.H. Magnetic nanoparticles. J. Magn. Magn.Mater.1999, 200, 359–372.
  28. Chang, L.L.; Erathodiyil, N.; Ying, J.Y. Acc. Chem. Res. 2012, 46, 1825–1837.
  29. Fujishima, A.; Zhang, X.; Tryk, D.A. Surf. Sci. Rep. 2008, 63, 515–582.
  30. Wang, X.; Starz-Gaiano, M.; Bridges, T.; Montell, D. Protoc, Exch,2008, 28.
  31. Mahdavian, L.; Monajjemi, M. Microelectronics Journal. 2010,41(2-3), 142-149
  32. Ali R. Ilkhani .; MajidMonajjemi, Computational and Theoretical Chemistry.2015, 1074 19–25
  33. Monajjemi,M *.; Bagheri,S.; Moosavi,M.S..; Moradiyeh,N.; Zakeri,M.; Attarikhasraghi,N.; Saghayimarouf,N.; Niyatzadeh,G.; Shekarkhand,M.; Mohammad S. Khalilimofrad, Ahmadin,H.; Ahadi,M.; Molecules 2015, 20, 21636–21657;
  34. Monajjemi, M., Chahkandi, B. Journal of Molecular Structure: THEOCHEM, 2005, 714 (1), 28, 43-60.
  35. Monajjemi, M.; Rajaeian, E.; Mollaamin, F.; Naderi, F.; Saki, S. Physics and Chemistry of Liquids. 2008, 46 (3), 299-306
  36. Monajjemi, M.;  Razavian, M.H.;  Mollaamin,F.;  Naderi,F.;  Honarparvar,B.; Russian Journal of Physical Chemistry A , 2008 , 82 (13),  2277-2285
  37. Monajjemi, M. Chemical Physics. 2013, 425, 29-45
  38. Monajjemi, M.; Ketabi, S.; Amiri, A. Russian Journal of Physical Chemistry, 2006, 80 (1), S55-S62
  39. Monajjemi, M.; Wayne Jr, Robert. Boggs, J.E. Chemical Physics.2014, 433, 1-11
  40. Monajjemi, M.; Honarparvar, B.; Nasseri, S. M. .; Khaleghian M. Journal of Structural Chemistry. 2009, 50, 1, 67-77
  41. Ardalan, T.; Ardalan, P.; Monajjemi, M. Fullerenes, Nanotubes, and Carbon Nanostructures, 2014, 22: 687–708
  42. Monajjemi, M.;  Karachi, N.; Mollaamin, F. Fullerenes, Nanotubes, and Carbon Nanostructures, 2014, 22: 643–662
  43. Yahyaei, H.; Monajjemi, M. Fullerenes, Nanotubes, and Carbon Nanostructures.2014, 22(4), 346–361
  44. Monajjemi, M. Falahati, M.; Mollaamin, F.; Ionics, 2013, 19, 155–164
  45. Monajjemi, M.; Mollaamin, F. Journal of Cluster Science, 2012, 23(2), 259-272
  46. Tahan, A.; Monajjemi, M. Acta Biotheor,2011, 59, 291–312
  47. Lee, V.S.; Nimmanpipug, P.; Mollaamin, F.; Kungwan, N.; Thanasanvorakun, S..; Monajjemi, M.  Russian Journal of Physical Chemistry A, 2009,83, 13, 2288–2296
  48. Monajjemi, M.; Heshmat, M.; Haeri, HH, Biochemistry (Moscow), 2006, 71 (1), S113-S122
  49. Monajjemi, M.; JafariAzan, M.; Mollaamin, F. Fullerenes, Nanotubes, and Carbon Nanostructures.2013, 21(6), 503–515
  50. Mollaamin, F.; Monajjemi, M.Physics and Chemistry of Liquids .2012, 50,  5,  2012, 596–604
  51. Monajjemi, M.; Khosravi, M.; Honarparvar, B.; Mollaamin, F.; International Journal of Quantum Chemistry, 2011, 111, 2771–2777
  52. Monajjemi, M.; Baheri, H.; Mollaamin, F.  Journal of Structural Chemistry.201152(1), 54-59
  53. Mahdavian, L.; Monajjemi, M.; Mangkorntong, N. Fullerenes, Nanotubes and Carbon Nanostructures, 2009, 17 (5), 484-495
  54. Monajjemi, M.; Farahani, N.; Mollaamin, F. Physics and Chemistry of Liquids, 2012, 50(2) 161–172
  55. Monajjemi, M.  TheorChemAcc, 2015, 134:77 DOI 10.1007/s00214-015-1668-9
  56. Monajjemi, MJournal of Molecular Modeling, 2014, 20, 2507
  57. Monajjemi , M.; Honarparvar, B.; Monajemi, H.;.Journal of the Mexican Chemical Society, 2006, 50 (4), 143-148
  58. Monajjemi, M.; Khaleghian, M.; Mollaamin, F.  Molecular Simulation. 2010, 36, 11,  865–
  59. Monajjemi, M.  Biophysical Chemistry.2015207,114 –127
  60. Sarasia, E.M.; Afsharnezhad, S.; Honarparvar, B.; Mollaamin, F.; Monajjemi, M. Physics and Chemistry of Liquids.2011, 49 (5), 561-571
  61. Amiri, A.; Babaeie, F.; Monajjemi, M.Physics and Chemistry of Liquids. 2008, 46, 4, 379-389
  62. Jalilian,H.; Monajjemi, M. Japanese Journal of Applied Physics. 2015,54, 8, 08510
  63. Naghsh,F, orient.jchem,2015, 31(1) 465-478
  64. Chitsazan, A, orient.jchem,2015, 31(1) 393- 408
  65. Barmaki, Z, orient.jchem, 2015, 31(3) 1723-1733
  66. Bonsakhteh, B.; Rustaiyan, A.H, orient.jchem, 2014, 30(4) 1703-1718


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