Cyanometallate incorporated supramolecular networks based on a nitroalkyl-substituted CuIIN4 precursor: Synthesis, crystal structure, thermal and electrochemical studies
                                
                                    
                                        作者:Ambarish Ray、Parikshit Chandra Mandal、Atish Dipankar Jana、William S. Sheldrick、Swastik Mondal、Monika Mukherjee、Mahammad Ali                                    
                                    
                                        DOI:10.1016/j.poly.2008.06.035
                                    
                                    
                                        日期:2008.9
                                    
                                    Two new copper(II) complexes, viz. [Cu(nelin)(H2O)(2)](2)[Fe(CN)(6)] center dot 6H(2)O (2) and [Cu(nelin)}(2)Ni(CN)(4)]-(ClO4)(2) center dot 2H(2)O (3), have been synthesized using [Cu(nelin)](ClO4)(2) (1) (nelin = 1,9-diamino-5-methyl-5-nitro-3,7-diazanonane) as a nitroalkyl-substituted (CuN4)-N-II precursor, and their structures and supramolecular networks have been fully explored using the single crystal X-ray diffraction technique. The H-bonded 1 D chains of 2 run along the a-axis, being generated from supramolecular synthons using cations and anions, and are further propagated into a 3D array to form irregular honeycomb-like channels which are divided into two halves, with each half accomodating a helical water chain running in opposite directions to each other. In complex 3, the trinuclear units are arranged in successive rows in a herring-bone fashion and bifurcated hydrogen bonding through the uncoordinated terminals of the [Ni(CN)(4)](2-) units give rise to a supramolecular (4,4) network. A comparison of the PXRD pattern of complex 2 and its dehydrated form indicate marked changes in the diffraction pattern with the development of a quasi glassy nature in the dehydrated form. The electrochemical properties of 1, 2 and 3 have been investigated in comparative ways using the cyclic voltammetric technique in aqueous and MeCN solutions with Ag/ AgCl as a reference electrode. Electrochemical reduction generates the one-electron reduced nitro-radical anion. In water-alcohol glass at 77 K complex 2 exhibits a typical four-line hyperfine EPR spectra with g(parallel to) = 2.11, g(perpendicular to) = 2.02, A(parallel to) = 150 Oe and A(perpendicular to) = 5 Oe at nu = 9.45 MHz. (C) 2008 Elsevier Ltd. All rights reserved.