REACTIONS OF CUX (X=SCN AND CN) WITH 2-BENZOYLPYRIDINE - SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF XO-INDOLO[1,2-A]PYRIDINIUM]DITHIOCYANATOCUPRATE(I) AND POLYMERIC MU-CYANO(2-BENZOYLPYRIDINE) COPPER(I)

When a mixture of excess CuSCN and 2-benzoylpyridine (2-Bzpy) stands i n an ethanolic medium for about ten days in contact with air, the intr amolecular oxidative cyclization of 2-Bzpy occurs with formation of th e ionic compound [9-oxo-indolo[1,2-a]pyridinium](+)[Cu(SCN)(2)](-) (1) . In contrast, interaction of CuCN and 2-Bzpy in ethanol leads to form ation of the polymer [Cu(CN)(2-Bzpy)](n) (2). The reaction of Cu(II) a nd 2-Bzpy in presence of excess SCN- in ethanol affords (1) and the gr een monomer [Cu(SCN)(2)(2-Bzpy)(2)] (4). These complexes, along with t he 1:1 CuSCN complex of 2-Bzpy (3) are studied by IR, Raman and electr onic spectroscopic methods and X-ray structural analysis of (1) and (2 ). Crystals of (1) are monoclinic, space group P2(1)/n (No. 14), with a = 5.887(1), b = 36.142(7), c = 7.083(1) Angstrom, B = 109.56(1)degre es, Z = 4, and R(F) = 0.033 for 2487 observed MoK alpha data, (2) mono clinic, space group P2(1)/c (No. 14), a = 14.393(3), b = 8.881(2), c = 9.287(2) Angstrom, B = 103.80(3)degrees, Z = 4, and R(F) = 0.036 for 2030 observed MoK alpha data. The structure of (1) consists of a packi ng of [9-oxo-indolo [1,2-a]pyridinium](+) cations and [Cu(SCN)(2)](-) anions. Puckered layers are formed by the [Cu(SCN)(2)](-) component wi th four-coordinate Cu(I) and one tridentate mu(N,S,S)-thiocyanato liga nd. Complex (2) features distorted tetrahedral Cu(I) geometry, formed by a bidentate chelating 2-Bzpy and linear C- and N-bonded bidentate c yano groups, which link adjacent copper centers to form zigzag chains extending along the c axis. Complexes (1) and (2) do not fluoresce at room temperature.