Chelate ring stacking interactions in the supramolecular assemblies of Zn(ii)and Cd(ii) coordination compounds: a combined experimental and theoretical study. Issue 10 (16th February 2017) - Afkhami, Farhad Akbari
Abstract : We report seven Zn(ii )/Cd(ii ) complexes with picolinoyl/isonicotinoyl hydrazone based ligands exhibiting relevant chelate–π interactions. Abstract : The self-assembly of Zn(ii ) and Cd(ii ) ions with two isomeric tetradentate ligands, 2-pyridyl-isonicotinoylhydrazone (HL 1 ) and 2-benzoylpyridyl-picolinoylhydrazone (HL 2 ), was studied by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction. The reaction of zinc(ii ) and cadmium(ii ) salts with HL 1 and HL 2 in methanol under solvothermal conditions produced six monomer and one tetranuclear zinc(ii ) complexes, namely, Zn(HL 1 )Br2 (1 ), Zn(HL 1 )Cl2 (2 ), [Cd(HL 1 )2 ](NO3 )2 ·H2 O (3 ), Cd(HL 2 )Br2 (4 ), Zn(HL 2 )Cl2 (5 ), Zn(HL 2 )Br2 (6 ) and [Zn4 (L 2 )4 I2 ][ZnI4 ]·2H2 O (7 ). The structure of7 includes a cationic tetranuclear cluster of four zinc ions, four ligands, and two anions, counterbalanced by ZnI4 2− ions. However, the reaction of zinc(ii ) and cadmium(ii ) salts with HL 1 under the same conditions produced monomer compounds. Herein, the ligand effects on the complex structures were studied. Hirshfeld surface analysis and fingerprint plots facilitate the comparison of intermolecular interactions in compounds1–7, which are crucial in building supramolecular architectures.