Syntheses, crystal structures, and magnetic properties of four novel Cu(I/II) complexes

Four coordination compounds (CuCuI)-Cu-II(O2N-ipO)(4,4'-bpy) (1), [Cu-6(II)(O2N-ipO)(4)btp(H2O)(8)]center dot 6H(2)O (2), [Cu-12(II)(O2N-ipO)(8)(bth)(4)(H2O)(10)]center dot 2H(2)O (3), and [Cu-18(II)(O2N-ipO)(12)(btp)(3)(H2O)(18)(EtOH)(6)]center dot 13H(2)O (4) (4,4'-bpy = 4,4'-dipyridyl, btp = 1,3-bis(1,2,4-triazol-1-yl)propane, bth = 1,6-bis(1,2,4-triazol-1-yl)hexane and O2N-ipO = deprotonated 5-NO2-2-hydroxyisophthalic acid, Chart 1) were synthesized and crystallographically characterized. The common building unit [Cu-2(O2N-ipO)(2)] (O2N-ipO = deprotonated 5-NO2-2-hydroxyisophthalate, in-situ formed in the reaction of 5-NO2-1,2,3-benzenetricarboxylic acid (O2N-btcH(3)) with CuCl2 center dot 2H(2)O under hydrothermal conditions) features a diamond-shaped dinuclear motif, in which two Cu atoms are bridged by the deprotonated 2-hydroxo groups from different O2N-ipO ligands. Compound 1 exhibits a three-dimensional (3D) wave-like structure composed of [Cu-2(II)(O2N-ipO)(2)](2) and [Cu-2(I)(4,4'-bpy)(2)](2+) subunits, while 2 displaying a 1D alternate double-chain structure based on units of [Cu-2(II)(O2N-ipO)(2)] and [(CuNO4)-N-II]. Compounds 3 and 4 are discrete polynuclear species featuring a dodeca- and a octadeca-nuclear core based on units of [Cu-2(II)(O2N-ipO)(2)] and [(CuNOn)-N-II], respectively. These compounds were further characterized by elemental analyses, FTIR, PXRD and thermogravimetric analyses. In addition, we studied their magnetic properties via direct current magnetic susceptibility measurements. (C) 2011 Elsevier B. V. All rights reserved.