Coordination assembly of p-substituted aryl azo imidazole complexes: Influences of electron donating substitution and counter ions
摘要:
The formation of a series of Cu(II), Zn(II) and Cd(II) complexes using the p-substituted aryl azo system has been reported. Presence of electron donating -Me, -OMe groups impart some unusual coordination behaviors in Cu(II) complexes. Varying coordination mode and electron density in the ligand results in the formation of an unusual Cu-S bond in complex 1 and an unusual equatorial coordination of H2O in Cu(II) complex 2 with a square-pyramidal geometry.The hydrogen bonding site along with the metal coordination site in the ligand results in the formation of higher dimensional self-assembled supramolecular architectures. Compatibility of the hard-soft nature of the metal ion and symbiosis effect of the ligand with metal is responsible for the formation of long range higher dimensional networks in the solid-state, which were confirmed by single crystal X-ray structure analysis. Furthermore, various physicochemical studies, viz, thermal behaviors, absorption spectra, electrochemistry and EPR studies, have been conducted to rationalize the structures in the solution phase. (c) 2010 Elsevier Ltd. All rights reserved.