SYNTHESIS, CRYSTAL STRUCTURE AND PROPERTIES OF A 4,4'-BIPYRIDINE BRIDGED TRIGONAL-BIPYRAMIDAL COPPER HOMOBINUCLEAR COMPLEX WITH TRIS(2-AMINOETHYL)AMINE

摘要

The synthesis of the binuclear complex [(tren)Cu(4,4'-bipy)Cu(tren)] (ClO_4)_4 where trend = tris(2-aminoethyl) amine and 4,4'-bipy = 4,4'-bipyridine, is described. Single-crystal X-ray diffraction study of the homobinuclear complex shows that two copper(II) ions are bridged by 4,4'-bipyridine and each copper(II) ion is trigonal-bipyramidally coordinated, with trend occupying four sites [Cu-N = 2.030(2), 2.047(2), 2.078(2), and 2.199(2) A respectively] and a bridging 4,4'-bipyridine in the apical position. The Cu-Cu distance is 11.11 A. In variable-temperature ESR spectra, the presence of hyperfine structure suggest that some interaction exists between the two copper(II) ions. Temperature-dependent susceptibility studies indicate that it is a weak ferromagnetic interaction with 2J = 1.23 cm~(-1).