Polymer complexes: XLXII-interplay of coordination π-π stacking and hydrogen bonding in supramolecular assembly of [sulpha drug derivatives-N,S:N,O] complexes

A novel series of nickel(II) polymer complexes of 5-sulphadiazineazo-3-phenylamino-2-thio-4-thiazolidinone (HL1), 5-sulphamethazine-3-phenylamino-2-thioxo-4-thiazolidinone (HL2), 5-sulphamethoxazole-3-phenylamino-2-thioxo-4-thiazolidinone (HL3), 5-sulphacetamide-3-phenyl-2-thioxo-4-thiazolidinone (HL4) and 5-sulphaguanidine-3-phenylamino-2-thioxo-4-thiazolidinone (HL5) were prepared and characterized. IR spectra show that HLn (n = 1-5) is coordinated to the metal ion in a neutral tetradentate manner with NSNO donor sites of NH (hydrazone's), NH (3-phenylamine), carbonyl group and Ph-NH. The title [Ni-3(HLn)(2)(mu-OAc)(2)(OAc)(4)](n) consists of three Ni(II) atoms linked by interchain pi-pi interaction are observed between aromatic rings of two ligands (HLn) which are further doubly bridged two adjacent nickel atoms by acetate group. The geometrical structures of these complexes are found to be octahedral. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, thermal, infrared, H-1 NMR, electronic spectra, magnetic susceptibility and conductivity measurements. The richness of electronic spectral in these complexes is also supporting evidence for the trinuclearity of the Ni(II) polymer complexes. (C) 2010 Elsevier B.V. All rights reserved.