Synthesis, structure and properties of hexacoordinated compounds of cadmium(II) halides/pseudohalides containing a pentadentate N-donor Schiff base

Five hexacoordinated compounds of type [Cd(L)(X)]Y·nMeCN (1–5) [L = N,N′-(bis(pyridin-2-yl)benzylidene)diethylenetriamine; Y=PF6-, n = 1; X = Cl− (1), Br− (2), I− (3) and Y=PF6-, n = 0, X=N3-, (4); Y=ClO4-, n = 0, X = NCO−, (5)] are synthesized and characterized. Structures of all the compounds are solved by X-ray diffraction measurements. Structural analyses reveal that each cadmium(II) center adopts a distorted octahedral geometry bound by five N atoms of L along with terminal halide in 1–3 and N atom of terminal pseudohalide in 4 and 5. Intermolecular NH⋯O, CH⋯O, NH⋯F and CH⋯F hydrogen bondings and CH⋯π interactions as is the case lead to different crystalline aggregates in 1–5. The complexes display intraligand 1(ππ*) fluorescence in DMF solutions at room temperature.

► Five mononuclear cadmium(II) halides/pseudohalides are synthesized.
► X-ray structural analysis define their molecular and crystalline architectures.
► The Schiff base compounds are examples of luminous materials.