Two Copper(II) Complexes with Mono-Oxime Chelating Ligands: Synthesis, Crystal Structure, and Substituent Effect.

Two new complexes, [Cu(L1)2] (1) and [Cu(L2)2(H2O)]·CH3OH (2), have been synthesized via the complexation of copper(II) acetate monohydrate with two mono-oxime chelating ligands (HL1: 4-[(Methoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H- pyrazol-3(2H)-one and HL2: 4-[(Ethoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one), respectively. X-ray crystal structure determination of the two complexes show that complex 1 consists of one copper(II) ion, two bidentate (L1)- units, and the copper atom of complex 1 has a square planar geometry distorted tetrahedrally with four-coordination, while complex 2 consists of one copper(II) ion, two bidentate (L2)- units, one coordinated H2O, and one crystallizing methanol molecule, as expected from the analytical data. And the copper atom of complex 2 has a slightly distorted tetragonal pyramid geometry with five-coordination. Complex 2 is a self-assembling infinite chain supramolecular structure formed by intermolecular hydrogen bonds. Meanwhile, the photophysical properties of the resulted complexes have also been discussed. [ABSTRACT FROM AUTHOR]