New tetrahedral and trigonal-bipyramidal Cu(II) chelate complexes synthesized with aryl-substituted glyoxalanil-(1)-phenylhydrazones-(2). The IR and electronic spectra

The new Cu(II) chelate complexes I and II synthesized with ligands from, the class of 1-methyl-2-carbethoxyglyoxalanil-(1)-phenylhydrazones-(2) differently substituted at the benzene rings, namely p-CH3O at both rings (1) and p-CH3O at the anil group and p-NO2 at the phenylhydrazonic group (II) show different structures. Both in solid state and solutions the complex I has a distorted T-d Structure (real symmetry D-2d or even C-s), whereas the complex II has in solid state a trigonal-bipyramidal and a distorted T-d structure in solutions. In the absorption spectrum of complex I three weak d-d bands (at > 1200; similar to 915 and similar to 690 nm), three stronger L --> M CT bands (at similar to 750; 615 and similar to 500 nm) and two very strong intra-ligand pi--> pi* bands (at 417 and 363 nm) are put into evidence through Gaussian analysis. At complex I the whole splitting between the "d"-type'M,O. is at least of similar to 14500 cm(-1), i.e. by similar to 80% larger than in the case of a hypothetical regular T-d Cu(II) complex.