Abstract

Deepika Jaiswal and Sudha Yadava

DOI : http://dx.doi.org/10.13005/ojc/340625

Some novel mixed ligand complexes of Mn(III) with glycine ligand namely [Mn(gly)₂ Cl(en)],  [Mn(gly)₂ Br(en)], [Mn(gly)₂ N₃ (en)] and [Mn(gly)₂ NCS(en)] have been synthesized starting from Mn(gly)₂ Cl, Mn(gly)₂ Br, Mn(gly)₂N₃ and Mn(gly)₂ NCS respectively. These newly synthesized complexes have been characterized by UV/Vis, FT-IR and Mass spectrometry. The spectroscopic data suggest distorted octahedral geometry for all these mixed ligand complexes. The λmax values of these complexes for ⁵T₂g → ⁵Eg transitions are 482 nm for [Mn(gly)₂N₃(en)], 488 for [Mn(gly)₂NCS(en)], 486 for [Mn(gly)₂ Br(en)] and 484 for [Mn(gly)₂Cl(en)], all these transitions are red shifted in comparison to their parent complexes. The ligand field parameters such as 10 Dq, B and β have also been calculated and suggest covalent metal ligand bonding. One peculiar finding is that the FT-IR spectra shows frequencies for both free and coordinated NH₂ group in all complexes indicating that the ethylenediamine ligand present here is non bridging in nature. The mass spectrometry results show molecular ion peaks at m/z  300, 345, 307 and 323 for [Mn(gly)₂Cl(en)],  [Mn(gly)₂Br(en)], [Mn(gly)₂N₃(en)] and [Mn(gly)₂NCS(en)] respectively. The coordination of ethylenediamine to Mn(III) enhances its efficiency towards decolourization methyl red dye.

Dye Decolourization; Ethylenediamine; Glycine; Mn(III) Mixed Ligand Complexes

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