Self-organized three dimensional architectures based on non-covalent interactions in square planar Cu(II) thiosemicarbazone: Solvent mediated crystallization and EPR based correlation study

摘要

A series of copper complexes of 2-acetylpyridine-N-4-methylthiosemicarbazone (HL4M) were synthesized and characterized by elemental analyses, UV-Vis, FT-IR, conductivity and EPR studies. The molecular structures of [Cu(L4M)Cl] (1), [Cu(L4M)I] (2), [Cu(L4M)OAc].H2O (3) and [Cu(mu-S-L4M)(NCS)](2).DMSO (4) were confirmed by single crystal X-ray crystallography. Complexes 1, 2 and 3 have square planar geometry constituted by NNS donor sites from deprotonated thiosemicarbazone ligand and the fourth site is occupied by anionic group/atom. Complex 4 is a centrosymmetric dimer. The XRD results revealed that the solvents play a decisive role in the crystallization of products. These four complexes exhibit strong hydrogen bonding interactions in the solid state and are self-assembled into infinite 3D supramolecular structure via pi center dot center dot center dot pi stacking interactions. The g vertical bar vertical bar and A vertical bar vertical bar of complexes were analyzed by Peisach-Blumberg plot which proves an inverse correlation among NNS and ONS thiosemicarbazone complexes. (C) 2018 Elsevier B.V. All rights reserved.