Synthesis, crystal structures, thermal analysis and magnetic property of mono- and bi-nuclear 1,1-cyclobutanedicarboxylate copper complexes

Two new copper complexes, [Cu(cbdc)(phen)(H2O)]center dot 2H(2)O (1)and[CU2(cbdc)(phen)(2)(H2O)(2)](CIo(4))(2)-H2O (2) (cbdc=1,1-cyclobutanedicarboxylate and phen=1,10-phenanthroline), were synthesized by reaction of cbdc with CU(CI04)2 and phen in ethanol aqueous solution. Complex 1 crystallizes in monoclinic system with space group 3 P2(1)/c and a=0.9428(4) mn, b=1.2183(5) nm, c=1.6265(7) nm, ss=102.418(5)degrees, V=1.8246(13) nm, Z=4, R=0.0445, wR(2)=0.0947. The structure of 1 is discretely mononuclear, which is packed by pi(...)pi interaction forming a 3D supramolecular structure where Cu(H) ion is five-coordinated and has square-pyramidal coordination geometry. Its thermal decomposition procedure detail was studied by thermal analysis TG-DSC. Complex 2 belongs to monoclinic system with space group P2(1)/c and a=0.8897(3) nm, b=1.9130(8) nm, c=1.9936(8) nm, P=99.04(2)degrees ,V=3.351(2) nm(3), Z=4, R=0.0540, wR(2)=0.1102. The structure of 2 is a discrete binucleus, where Cu(1) is four-coordinated by phen and cbdc in a square-planar geometry while Cu(2) is five-coordinated by phen, one O of cbdc and two H2O, which can be best described as distorted trigonal-bipyramidal geometry. Cu(1) and Cu(2) are linked by carboxytic group of cbdc in a bidentate bridging fashion. Variable-temperature magnetic susceptibilities of 2 in 2--300 K showed that its magnetic behavior obeyed Curie law.