The influence of substituents at C2/N1 atoms of pyridine-2-formaldeyhde-/benzaldehyde-N1-substituted thiosemicarbazones on the type of copper(I) complexes

Abstract Equimolar reaction of copper(I) iodide with PPh 3 in acetonitrile formed compound of empirical composition, {CuI(Ph 3 P)} and its further reaction in chloroform with pyridine-2-carbaldehyde-N-methyl thiosemicarbazone {(C 5 H 4 N)HC 2 N 3 -N 2 -(H)-C 1 ( S)N 1 HR; R = Me; HL 1 -Me} formed crystals of complex, [CuICl(Ph 3 P)(κS 1 -H 2 L 1 -Me] 1a , tetramer [Cu 4 I 4 (Ph 3 P) 4 ] 1b and free HL 1 -Me 1c , separated from the same reaction vessel. The formation of product 1a involved abstraction of chlorine from chloroform and has pyridine-N-protonated thio-ligand. Copper(I) bromide/chloride with Ph 3 P and HL 1 -Me or HL 1 -Et also formed pyridyl protonated, [CuBr 2 (Ph 3 P)(κS 1 -H 2 L 1 -Me)] 2 , [CuCl 2 (Ph 3 P)(κS 1 -H 2 L 1 -Me)] 3 , [CuBr 2 (Ph 3 P)(κS 1 -H 2 L 1 -Et)] 4 and [CuCl 2 (Ph 3 P)(κS 1 -H 2 L 1 -Et)] 5 . The products similar to 1b and 1c were also identified in these reactions. In these four coordinated complexes the pyridine protonated thio-ligands are coordinating through sulfur only. Copper(I) halides with benzaldehyde-N 1 -substituted thiosemicarbazones {(C 6 H 5 )HC 2 N 3 -N 2 (H)-C 1 ( S)-N 1 HR ; R = Me, Et; HL 2 -Me; HL 2 -Et} and Ph 3 P have yielded halogen bridged dinuclear complexes, [Cu 2 (μ-X) 2 (κS 1 -HL 2 -R) 2 (Ph 3 P) 2 ] (X, R: I, Me, 6 ; Br, Me, 7 ; I, Et, 8 ; Br, Et, 9 ; Cl, Et, 10 ). For R = phenyl at N 1 atom, copper(I) halides with two m moles of HL 2 -Ph have formed sulfur–bridged dinucelar complexes, namely, [Cu 2 (μ-S-HL 2 -Ph) 2 (κS 1 -HL 2 -Ph) 2 X 2 ] (X = I, 11 , Br, 12 , Cl, 13 ). Complexes have been characterized using analytical data, IR, proton NMR and single crystal X-ray crystallography ( 1–5, 7, 9, 11 and 12 ). The coordination environment of the Cu in complex 1a contains both Cl and I, but both sites are disordered.