Abstract
The 20-, 34- and 36-membered macrocyclic of bis (dithiodimine) Schiff base ligands, Bis-N,N'(dithiocarbonyl) terephthliden (L1), Bis-N,N'[1,3(o-aminophenylthio)-propane] terephthylidene (L2) and Bis-N,N-[1,4(o-amino phenylthio)-butane] terephthylidene (L3), have been prepared by a (2+2) condensation of terephthaldehyde with dithiooxamide or 1,3-bis-(o-aminophnylthio) propane, or 1,4-bis-(o-aminophenylethio)-butane. Air stable dinuclear complexes of Co2+, Ni2+ and Cu2+ were obtained from reaction of metal salts with L1, L2 and L3 in tetrahydrofuran. Ligands consist of two S2N2 donor sites coordinated with the metal ions. Also, adducts of the cobalt complex with 1,4-phenelyene diamine was also presented. CHN elemental analysis, metal content, molar conductivity, magnetic measurements, proton nuclear magnetic resonance, UV-visible and infrared spectral studies have characterized the complexes and adducts. In addition to this, the DFT i.e. Density Functional Theoretical calculations has been used for supporting experimental data. This process used B3LYP functional method. It is the method which has been introduced due to Yang, Parr and Lee. This method is comprised of 3-parameter functional because of the presence of Axel Becke. It further incorporates the basis set of Los Alamos National Laboratory 2 double-zeta (LANL2DZ). Furthermore, the calculation associated with the molecule's vibrational frequencies was calculated with the help of optimized geometry. Tetrahedral and square planar geometry around Co2+, Ni2+ and Cu2+ have been deduced on the basis of magnetic and spectra studies..