ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Self-assembly hydrogen-bonded supramolecular arrays from copper(II) halogenobenzoates with nicotinamide: Structure and EPR spectra
Jozef Halaška, Danica Čechová, Michael K. Lawson, Zdeňka Růžičková, Vladimír Jorík, Marian Koman, Marian Valko, Bojan Kozlevčar, and Ján Moncol
Faculty of Chemical and Food Technology, Slovak University of Technology, SK-81237 Bratislava, Slovakia
Abstract: Nicotinamide was employed as a supramolecular reagent in the synthesis of six new copper(II) bromo-, iodo-, fluoro- and dibromobenzoate complexes. Structures of [Cu(2-Brbz)2(nia)2(H2O)2] (I ), [Cu(2-Ibz)2(nia)2(H2O)2] (II ), [Cu(2-Fbz)2(nia)2(H2O)2] (III ), [Cu(4-Brbz)2(nia)2(H2O)2] (IV ), [Cu(3,5-Br2bz)2(nia)2(H2O)2] (V), [Cu(F-Fbz)2(nia)2(H2O)] · H2O (VI ) (nia = nicotinamide, 2-Brbz = 2-bromobenzoate, 4-Brbz = 4-bromobenzoate, 3,5-Br2bz = 3,5-dibromobenzoate, 2-Ibz = 2-iodobenzoate, 2-Fbz = 2-fluorobenzoate, 4-Fbz = 4-fluorobenzoate) were determined using X-ray analysis. Compound [Cu(2-Brbz)2(nia)2] · 2H2O (VII ) was prepared by a new method and also characterized by X-ray powder diffraction and EPR spectroscopy. Compounds I-V are monomeric complexes with a square-bipyramidal coordination sphere around the Cu2+ ion. Complex VI is monomeric with coordination environment around the Cu2+ ion of a tetragonal-pyramid. Complexes I and VII present examples of coordination isomerism. Molecules of all compounds are connected by N-H···O and O-H···O hydrogen bonds from the NH2 groups of nicotinamide and water molecules which create supramolecular hydrogen-bonding-coordination chains and networks.
Keywords: copper(II) complexes – nicotinamide – crystal structure – EPR – supramolecular network
Full paper is available at www.springerlink.com.
Chemical Papers 70 (1) 101–113 (2016)