A combined experimental and computational study of supramolecular assemblies in two photoluminescent cadmium(II) complexes with halosalicylaldimine Schiff bases.

Two new cadmium(II) complexes, [Cd(L 1 )(OOCCH 3 )(OH 2 )] ( 1 ), [Cd 2 (L 2 ) 2 (μ-1,3-SCN) 2 (CH 3 OH) 2 ] ( 2 ), have been synthesized using two halosalicylaldimine Schiff bases, HL 1 and HL 2 {where HL 1 = 2-(2-(ethylamino)ethyliminomethyl)-4-bromophenol, and HL 2 = 2-(2-(dimethylamino)ethyliminomethyl)-4-chlorophenol}, respectively. Both complexes have been characterized by elemental and spectral analysis and their structures have been confirmed by single crystal X-ray diffraction studies. Complex 1 is mononuclear and the cadmium(II) centre is apparently coordinated by a tridentate Schiff base, a water molecule and a bidentate chelating acetate. The acetate group could also be thought of as a single entity occupying just one stereochemical site as evident from the small value of chelate bite angle. Complex 2 is dinuclear and contain octahedral cadmium(II) bridged by double end-to-end thiocyanates. Supramolecular interactions in both complexes were also explored. The theoretical study, carried out using density functional theory (DFT) calculations, is devoted to the analysis of the interesting supramolecular assemblies in the solid state of the structures, paying special attention to hydrogen bonding interactions involving the coordinated solvent molecules. [ABSTRACT FROM AUTHOR]