Synthesis, molecular structure, DNA binding and cleavage properties of a novel ternary Cu(II) complex containing dipyrido[3,2-a:2'3'-c]phenazine and L-tryptophanate

A ternary Cu(II) complex with dipyrido[3,2-a :2'3'-c]phenazine(dppz) and L-tryptophanate (L-trp) has been synthesized and investigated by elemental analysis, molar conductivity, IR and X-ray diffraction. The complex crystallizes in the monoclimic space group P2(1) with two molecules in a unit cell of dimensions, a 7.949(2) angstrom, b 10.724(3) angstrom, c 18.580(5) angstrom, beta = 93.697(5)degrees, V = 1580.7(8) angstrom(3), R-1 = 0.0310, and wR(2) = 0.0382. The central copper(II) ion has a distorted square-pyramidal geometry, in which the N,O-donor tryptophanate and N, N-donor heterocyclic base dppz are in the basal plane and a water molecule is coordinated at the axial site. DNA binding properties of the complex were studied by electronic absorption spectroscopy, fluorescence spectroscopy, and viscosity measurement. The DNA cleavage of the complex was investigated by agarose gel electrophoresis. The results show that the complex can bind DNA by intercalation and cleave pBR322 DNA in the presence of ascorbate.