Synthesis, crystal structure and DFT calculations of copper(I) complex of 2-nitrobenzaldehyde-N1-methyl-thiosemicarbazone

Abstract

Copper(I) halides (I, Br, Cl) reacted with 2-nitrobenzaldehyde-N¹-methylthiosemicarbazone (L = 2-NO₂-Hbtsc-N¹-Me) and triphenylphosphine in 1:1:2 (M:L:Ph₃P) molar ratio to form stoichiometric complexes, [CuX(h¹-S-2-NO₂-Hbtsc-N¹-Me)(Ph₃P)₂] (X  = I (1), Br (2), Cl (3)). Formation of these complexes has been confirmed by elemental analysis, IR and ¹H NMR. The X-ray structure of complex 1, showed the presence of two molecules with slightly different bond parameters. Geometry around copper(I) center is distorted tetrahedral. Two molecules are interconnected by H-bonding between imino nitrogen N(14) of one molecule and phenyl hydrogen of one of the triphenylphospine molecules of the second molecule, {H(14)N×××HC, 2.701 Å, N×××H-C, 156.85°) forming a H-bonded dimer. The geometry of the thione ligated copper(I) complex was optimized in gas phase by employing B3LYP/6-31G(d, p) method using Gaussian 09 software package. The optimized geometry of the copper(I) complex displays similar structure as that of the crystal structure of complex 1.