名称:
Synthesis, X-ray crystal structures, spectroscopic properties and magnetism of copper(II) compounds of formula trans-Cu(LL)2(anion)2, with N-(pyridin-2-yl)acetamide and N-(pyrimidin-2-yl)acetamide as ligands: Unexpected absence of hydrogen bonding to the non-coordinating nitrogen atom of the ligand
摘要:
A coordination chemistry and lattice engineering study of 10 new Cu(II) compounds with the ligands N-(pyridin-2-yl)acetamide (Haap) and N-(pyrimidin-2-yl)acetamide (Haapm) with the general formula Cu(LL)(2)(anion)(2) is described. The bidentate ligands bind in a N,O-chelating mode and the used anions are ClO4-, CF3SO3-, BF4-, NO3-, Cl-. For five of the compounds a 3D crystal and molecular structure analysis has been performed. All Cu(II) ions have a tetragonal-based geometry; the basal plane of each copper consists of a N and an O atom of two different bischelating N,O-donor ligands; Cu-N distances vary from 2.00 to 2.04 angstrom and Cu-O distances are between 1.93 and 1.96 angstrom, whereas the apical sites are occupied by an atom of the anions, thereby providing an elongated octahedral geometry (Cu-anion contacts are between 2.41 and 2.81 angstrom).The intermolecular interactions are all involving multiple H-bond systems, providing a 2D polymeric array for most of the compounds. The chloride compound forms a zigzag polymeric array of hydrogen bonds. Most surprisingly, the lion-coordinating pyrimidine nitrogen atom, does not take part in any lattice hydrogen bonding. (c) 2007 Elsevier Ltd. All rights reserved.