Synthesis, Crystal Structures, Thermal Analysis and Magnetic Property of Mono‐ and Bi‐nuclear 1,1‐Cyclobutanedicarboxy‐ late Copper Complexes

Two new copper complexes, [Cu(cbdc)(phen)(H 2 O)]·2H 2 O ( 1 ) and [Cu 2 (cbdc)(phen) 2 (H 2 O) 2 ](ClO 4 ) 2 ·H 2 O ( 2 ) (cbdc=1,1‐cyclobutanedicarboxylate and phen=1,10‐phenanthroline), were synthesized by reaction of cbdc with Cu(ClO 4 ) 2 and phen in ethanol aqueous solution. Complex 1 crystallizes in monoclinic system with space group P 2(1) /c and a =0.9428(4) nm, b =1.2183(5) nm, c =1.6265(7) nm, β =102.418(5)°, V =1.8246(13) nm 3 , Z =4, R =0.0445, wR 2 =0.0947. The structure of 1 is discretely mononuclear, which is packed by π···π interaction forming a 3D supramolecular structure where Cu(II) 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 P 2(1) /c and a =0.8897(3) nm, b =1.9130(8) nm, c =1.9936(8) nm, β =99.04(2)°, 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 H 2 O, which can be best described as distorted trigonal‐bipyramidal geometry. Cu(1) and Cu(2) are linked by carboxylic 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.