Synthesis, Crystal Structure and DFT Study of a Dinuclear Cu <sup>1</sup> Complex With (E)-2-Benzylidene-N-Methylhydrazinecarbothioamide: Role of Halogen-Hydrogen Bonds in Copper-Copper Bridge Bonding

Abstract

An equimolar reaction of copper(I) chloride with the (E)-2-benzylidene-N-methylhydrazine -carbothioamide (btscH-N 1 HMe) thio-ligand in acetonitrile followed by the addition of one mole of triphenyl phosphine(Ph 3 P) gave crystals of empirical composition, {CuCl(Ph 3 P)(btscH-N 1 HMe)}. The infrared spectroscopy, 1 H-NMR spectroscopy and single crystal x-ray crystallography revealed the formation of the di-nuclear compound, [Cu 2 (m-Cl) 2 (Ph 3 P) 2 (k 1 S-btscH-N 1 HMe) 2 ] 1 . Crystal Data : M, C 54 H 52 Cl 2 Cu 2 N 6 P 2 S 2 ; crystal system, triclinic; space group, Pī; a, 10.98950(10); b, 11.03070(10); c, 12.0049(2) A; a,104.4680(10); b, 92.4550(10); g, 113.6630(10).° Intermolecular H-bonding between dimeric units led to the formation of a H-bonded polymer. DFT calculations on complexes of copper(I) halides with model thiosemicarbazone {H 2 C 2 =N 3 -N(H)-C(=S)-N 1 HMe} and PH 3 as a co-ligand revealed the formation of halogen-bridged or sulfur-bridged dinuclear complexes without or with halogen - solvent / water hydrogen bonding. Some interesting conclusions are inferred based on experimental-theoretical correlations.