Alteration of Molecular Conformations, Coordination Modes, and Architectures for a Novel 3,8-Diimidazol-1,10-phenanthroline Compound in the Construction of Cadmium(II) and Zinc(II) Homochiral Coordination Polymers Involving an Auxiliary Chiral Camphorate Ligand

Abstract

A novel 3,8-diimidazol-1,10-phen (phen = phenanthroline) compound has been prepared from the carbon-nitrogen bond cross-coupling reaction. X-ray structural studies for this compound and its dihydrate reveal they have different molecular conformations (L(b) in 1 and L(c).2H(2)O in 2). Two cadmium(II) and one zinc(II) complexes of 3,8-diimidazol-1,10-phen, formulated as [Cd(2)(d-cam)(2)(L(a))(2)].(H(2)O)(6) (3), [Cd(2)(d-cam)(2)(L(a))(H(2)O)] (4), and [Zn(2)(d-cam)(2)(L(b))(2)].(H(2)O)(5) (5), have been obtained involving an auxiliary chiral ligand d-cam (a dianion of d-camphoric acid) where the 3,8-diimidazol-1,10-phen ligand shows different molecular conformations, coordination modes, and architectures. Furthermore, d-cam and 3,8-diimidazol-1,10-phen ligands exhibit different bridging fashions to construct a homochiral 2D coordination polymer 3 and two homochiral 3D coordination polymers 4 and 5. Density function theory computational studies on comparing the different molecular conformations of the 3,8-diimidazol-1,10-phen ligand as well as spectral, nonlinear optical, and thermal properties for related compounds before and after the metal-ion complexation have also been carried out.