Synthesis and spectral studies of some new dimeric [(μ-Cl)₂M₂(L)₂ · xTHF] [M = Zn(II) and Hg(II)] complexes containing Schiff-base ligands

Abstract

A series of binuclear Schiff-base complexes of zinc(II) and mercury(II) containing bidentate ligands (HL) [HL = salicylidene-2-methyl-1-aminobenzene (HL¹), salicylidene-2-aminopyridine (HL²), and salicylidene-3-nitro-1-aminobenzene (HL³)] with “N” and “O” donors have been synthesized by simple metathetic reactions of anhydrous metal chlorides with sodium salts of Schiff bases (in tetrahydrofuran (THF)/MeOH) in equimolar ratio to produce [(µ-Cl)₂M₂(L)₂ · xTHF] [where M = Zn(II) and Hg(II); L = HL¹, HL², and HL³; x = 0 for (1), (4), (6) and x = 2 for (2), (3), (5)]. The main emphasis on the complexes [(µ-Cl)₂M₂(L)₂ · 2THF] (2), (3), and (5) is given due to their five-coordinate environment around metal ions. The complexes have been characterized by elemental analyses (M, Cl, C, H, N), melting point, and spectral (FT-IR, ¹H-NMR, and ¹³C-NMR) studies. The structural composition of the complexes has been determined by FAB-MS spectral studies. FAB-MS showed the isotopic molecular ion peak [M⁺] and fragments supporting the formulation. Powder X-ray diffraction study of 6 is also reported showing the crystallite size (404.5 Å) of the complex.

Keywords:

• Synthesis, Schiff bases
• Metal complexes
• IR
• NMR
• FAB-MS
• PXRD

Acknowledgments

The authors are grateful to the Director, C.D.R.I., Lucknow for providing spectral and analytical data. Nanophosphor Application Center, University of Allahabad, is also acknowledged for helping with PXRD studies of one of the compounds. One of the authors (P.B.) thanks UGC for providing financial support.