Mono, di and trinuclear photo-luminescent cadmium(II) complexes with N2O and N2O2 donor salicylidimine Schiff bases: Synthesis, structure and self assembly

Four new octahedral cadmium(II) complexes, [(Cd)(L-1)(HL1)](ClO4) (1), [Cd-2(L-2)(2)(SCN)(2)(CH3OH)(2)] (2), [(CdL3)(3)(mu-1,1,1-OH)](ClO4)(2) (3) and [Cd-2(L-4)(2)(SCN)(NO3)] (4) have been synthesized using four Schiff bases, HL1, HL2, HL3 and HL4, (where HL1 = 2-(2-(ethylamino)ethyliminomethyl)phenol, HL2 = 2-(2(dimethylamino)ethyliminomethyl)-4-bromophenol, HL3 = 2-(2-(diethylamino) ethyliminomethyl)-6-methoxyphenol and HL4 = 2-(2-(ethylamino) ethyliminomethyl)-6-methoxyphenol). All four complexes have been characterized by elemental and spectral analysis and structures have been confirmed by single crystal X-ray diffraction studies. Complex 1 is a mononuclear cationic bis-ligand complex. Complex 2 features a double end-to-end thiocyanate bridged dinuclear cadmium(II) complex. Complex 3 has a partial cubane [Cd3O4] core in which three [CdL3] subunits are interconnected through two types of oxygen bridges afforded by phenoxo oxygen atoms of ligands and a central hydroxo group. Complex 4 has a double phenoxo bridged dinuclear structure. Supramolecular interactions in all four complexes were also explored. All four complexes show fluorescence. (C) 2015 Elsevier B.V. All rights reserved.