Synthesis, Magnetic and Spectroscopic Characterization of Copper(II) Toluate Complexes with Substituted Piperazines

Abstract

New copper(II) toluate complexes with the saturated heterocyclic bases [(L-L) having the tendency to coordinate through both 1 and 4 nitrogen atoms] 1-methylpiperazine, 1,4-dimethylpiperazine, 2,6-dimethylpiperazine and 1-phenylpiperazine have been prepared and characterized by physico-chemical and spectroscopic methods. All of the complexes were found to be antiferromagnetic with stoichiometries of the type Cu(OOCR) 2 (L-L) n (n 5 1 or 0.5, R 5 2-, 3-or 4-CH 3 C 6 H 4 ) except Cu(OOCC 6 H 4 CH 3 -4) 2 (L-L) (where L-L 5 2,6-dimethylpiperazine), which is magnetically dilute. The spin exchange parameter, 22J, for two of the antiferromagnetic complexes has been evaluated from magnetic susceptibility measurements at different temperatures. Binuclear copper(II) acetate monohydrate-like structure for the antiferromagnetic complexes of 1:1 stoichiometry and polymeric structure of the type Cu(OOCH) 2 (dioxan) 0.5 for the complexes of 1:0.5 stoichiometry have been proposed. The magnetically dilute complex has been assigned a polynuclear trans-pseudo-octahedral or polymeric square pyramidal structure.

COBALT(II), Ni(II), Cu(II), Zn(II), CD(II), Hg(II), U0(2)(VI) AND th(IV) COMPLEXES FROM ONNN SCHIFF BASE LIGAND

“…This shift indicates that the nitrogen atom of the N-CH 2 group no longer has a lone pair of electrons and it acquired a partial positive charge due to its coordination with the metal ion. Similar observations were made by earlier authors 10,26 . A broad band around the 3450-3340 cm -1 is observed in the infrared spectra of the complexes of Cu(II), Zn(II), Cd(II), Hg(II) and Th(IV).…”

“…The presence of lipophilic and polar substituents is expected to enhance antibacterial activity. Heterocyclic ligands with multifunctionality have a greater chance of interaction either with nucleoside bases (even after complexation with metal ion) or with biologically essential metal ions present in the biosystem can be promising candidates as bactericides since they always tend to interact especially with some enzymatic functional groups, in order to achieve higher coordination numbers 25,26 . Thus the antibacterial activity of metal complexes cannot be ascribed to chelation alone, but it is an intricate blend of all the above contributions.…”

Ternary complexes of copper(II) and cobalt(II) carboxylate with pyrazole based ligand: Syntheses, characterization, structures and bioactivities

“…Nitrogen containing heterocyclic compounds such as imidazole/ pyrazole plays important role in many bioactive compounds [19]. There are many reports on copper(II) and cobalt(II) alkyl/arylcarboxylate with nitrogen donor heterocycle ligands [20][21][22][23][24][25]. Since synthesis and structures of carboxylate containing ternary copper (II) and cobalt(II) complexes in presence of tetradentate N 4 -coordinating ligands are scare in the literature, we were interested to see the coordination behavior of carboxylate group in copper(II) and cobalt(II) complexes in presence of tetradentate ligand dbdmp.…”

catena-Poly[[(N,N-dimethylethane-1,2-diamine)copper(II)]-di-μ1,1-azido-[(N,N-dimethylethane-1,2-diamine)copper(II)]-di-μ1,3-azido]

“…Polynuclear complexes have played an important role in the development of coordination chemistry related to magnetism and molecular architectures (Eshel et al, 2000;Jiang et al, 2005;Escuer et al, 2000;El-Behairy et al, 1997;Manhas et al, 2005). The prime strategy for designing these molecular materials is to use suitable bridging ligands that determine the nature of the magnetic interactions (Salem, 2005;Dohlakiya & Patel, 2005).…”