U.V., E.P.R. & X.R.D. Spectral Analysis of Bromo Mn(II) tetra seleniazide complex

INTRODUCTION

The complexes of halogenated derivative of Se₄N₄ have been reported ^1,2 .  The adducts of Se₄N₃Cl with urea, thiourea, hydrazine and phenyl hydrazine have also been synthesized and reported ^3,4. The Mass  and I.R. spectral studies Mn (II), Fe(III), Co (II) complex with Se₄N₃Br have been reported by us ^5-7. The present investigations are in continuation of previous work.

EXPERIMENTAL

To synthesis the complex, first of all Se₄N₃Br was prepared by the reaction of dry HBr on Se₄N₄^8,9 which was prepared by the ammoniation of SeBr₄ in benzene. Equimoler ratio of MnCl₂ and Se₄N₃Br (1:1) was mixed and refluxed for 6 hrs. in DMF. The grayish product formed, was separated, washed with D.M.F. and alcohol, dried and stored in vacuum desiccators over fused CaCl₂.

U.V.,E.P.R, and X.R.D. spectra of complex, were recorded subsequently on Perkin-Elmer-Lambda-15 spectrophotometer (200-800nm) Varian’s X-E-4 band spectrometer at room temperature and PW-1710 X-ray power diffractometer usingλ =1.5418 ,  as source of radiation in the 2Θ range 0^o-80 .

RESULTS AND DISCUSSION

On the basis of the quantitative ,Mass & I.R. spectral analysis the complex bromo Mn(II) tetra seleniazide has been assigned as (Se₄N₃Br)₂MnCl₂ 4H₂O (loc. site). The U.V. spectrum (fig-1) consist three prominent peaks at 200. 222.5, 282.5 nm. Former two bands 200, 222.5, corresponding 6.2, and 5.57ev energy, showing the ionic environment are due to the charge transfer transition in the complex. The last band, 282.5nm is on account of P∏ -d∏ transition for Se₄N₃ ring present in the complex. This is also confirmed from the frequencies ratios v_1/ v₂  =1.27 less than 2. The oscillator strength ‘f’ of the order 10^-5(Table-1, Column-3) suggest the low spin Laporte forbidden transition in the complexes which is due to the sharing of electrons in Se₄N₃ ring. The low value of band gape energy,Δ Eg (Table-1,Column-4) and high value of number of conducting electrons, N_c of the order of 10⁵ expounds the good conductive nature of complex.

Fig1: U.V. spectrum of the Complex Click here to View Figure

 

Table1: U.V. and E.P.R. Spectral Data of the Complex Click here to View table

 

A single broad peak of high intensity has occurred in E.P.R. spectrum (fig-2) suggesting the paramagnetic character of complexes which is supported by the low value of magnetic susceptibility, =1.2352 10^-3 e.s.u. (Table-1, Column-10). The value of g_x = g_y = 1.9407 (Table-1,Column-7) less than two explore the presence of vacant 3d energy shells in Mn atom to accept the electron pairs form N atom of Se₄N₃ ring, forming coordinate bond. The value of g_z =2.0790 (Table-1,Column-8) greater than two indicate the sharing of electrons i.e. covalent bonding in Se₄N₃ ring of the complex.

Fig2: E.P.R. spectrum of the Complex   Click here to View Figure

 

Thus bromo Mn(II) tetra seleniazide, (Se₄N₃Br)₂MnCl₂ 4H₂O possess ionic bond due to Mn²⁺ and 2Cl^–,coordinate bond, Se N Mn and Se N, Se Br covalent linkage with the 3d⁵ configuration of Mn²⁺ because the value of  μ_eff=1.7215 is according to the presence of one unpaired electron. Thus the complex formed having quadridentated, coordinated linkage with square planar structure as reported (loc. site).

 

Fig3: X.R.D. Pattern of the Complex Click here to View Figure

 

The X.R.D. pattern of complex recorded in 2θ  range 0^o-80  (fig-3) possesses a strong and intense peak at 29.21  for the Se₄N₃ ring. From the X-ray pattern the values of sin^2 θ , miller indices, hkl, and inter planar distances ‘d’, calculated, resembles to the theoretical values (Table-2). From these X.R.D. data, the values of axial ratio and axial angles (Table-2) calculated are corresponding a₀≠ b₀≠ c₀≠ and a = β = _Y = 90⁰  for the orthorhombohedral geometrical packing of the molecule in the complex.

Table2: X-ray Diffraction pattern of complex Click here to View table

 

Fig4: Proposed Geometrical Structure of Complex, (Se4N3Br)2MnCl2.4H2O Click here to View Figure

 

ACKNOWLEDGMENT

Authors wish to express to thank to the Director SAIF, Punjab University Chandigarh, Director SAIF, IIT Bombay, Director ACMS IIT Kanpur  to provide instrumental facilities.

REFERENCES

1. Thewalt, U.; Holl, K.  Z. Naturforsch, 1984,Sec. B, 39, 145.
2. Chivers, T. The Chemistry of Inorganic Ring Systems; Steudel,R. (Ed.), Elsevier Science Publishers, Amstardam, 1992, p. 409 .
3. Dixit ,H.; Jadon, S.P.S. Int. J. Chem. Sci.,2005, 3(4), 709-714 .
4. Dixit,H.; Jadon, S.P.S. Asian J. Chem.,2006, 18(1), 295 .
5. Gupta, G.K.; Jadon, S.P.S. Int.J.Chem.Sci. 2009, 7(4), 2861-2866.
6. Gupta, G.K.; Jadon, S.P.S. Int.J.Chem.Sci. 2012,10(2), 1091-1095.
7. Gupta, G.K.; Jadon, S.P.S. Int.J.Chem.Sci. 2013,11(1), 306-312.
8. Gowik,P. ; Klopotke, T. Spectrochim Acta A. 1990,46, 1371.
9. Siivari, J.; Chivers,T.; Laitinen, R.S. Inorg. Chem.1993, 32, 1519.

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