CHARACTERIZATION OF IS(BETA-DIIMINO-TETRACYANOPYRROLIZINIDO)COPPER(II) COMPLEX - X-RAY CRYSTAL-STRUCTURE OF THE ACETONITRILE ADDUCT AND STRUCTURAL COMPARISON WITH THE TETRAHYDROFURAN DERIVATIVE

The X-ray crystal structure of the o-3,5-diimino-3,5-dihydro-pyrrolizi nido)copper(II) complex, as an adduct with acetonitrile, CuL2 . 2CH3CN (1a), is described and compared with that of the analogous tetrahydro furan derivative Cu L2 . 2THF (1b), previously reported. The molecular structure of both complexes is almost the same (the copper atom is ce ntrosymmetrically surrounded by four chelating imino groups in a squar e planar configuration), whereas the spatial arrangement is totally di fferent: in 1a the molecular units are slipped stacked, while in 1b th ey are mutually orthogonal. The results of a number of physical measur ements on both 1a and 1b are reported and correlated with the structur es. The solution electronic spectrum is also reported and compared wit h that, extraordinarily similar, of copper-phthalocyanine.