A new binuclear copper(II) complex, [Cu~2LBr~2]Br.3H~2O, where L is a new binucleating macrocyclic ligand 2, 6-bis(1, 5, 9- triazacyclododecan-9-ylmethyl) benzoate, has been prepared and characterized by X-ray crystallography. Crystal data: monoclinic, space group P2~1/c, a=1.1666(2), b=1.3541(3), c=2.2750(5)nm, β=99.38 (3)ⅲ, Z=4. The binuclear copper(II) center ions are bridged by a μ - carboxyl group of L and separated by 0.5884nm. Both of the copper(II) ion centers are coordinated by three amine nitrogens of [12] aneN~3 subunit and one oxygen of the carboxyl group, as well as one bromide ion. The copper(II) ion is in the trigonal bipyramid environment. Variable temperature magnetic susceptibility studies indicate that three exists intramolecular antiferro-magnetic coupling (J=-22.49cm^- ^1) between the two copper(II) centers.

Key words: COPPER COMPLEX, DINUCLEAR COMPLEX, CRYSTAL STRUCTURE, ANTIFERROMAGNETISM, NITROGEN HETEROCYCLICS, BENZENECARBOXYLIC ACID P