THE SYNTHESIS AND CRYSTAL-STRUCTURE OF [CR(ACACEN)PY2][ZNCL3PY]

The reduction of CrCl3 by zinc dust in THF solution followed by slow a ddition to an ethanolic solution K(acacen) gave a brown powder, which when reacted with pyridine produced an intractable brown tar. Careful recrystallization of the tar from methanol gave a small quantity of cr ystalline [Cr(acacen)py2][ZnCl3py]. The structure consists of a set of two crystallographically independent complex cations and anions of th e above formula. Crystal data: monoclinic space group P2(1), a = 12.66 7(4), b = 16.146(4), c = 16.262(5) angstrom, beta = 108.57(1)-degrees, V = 3153(2) angstrom3, Z = 4. A total of 7657 reflections was collect ed with graphite monochromated Mo Kalpha radiation (to 2theta = 54-deg rees), of which 4536 were used in subsequent structure solution and re finement (I greater-than-or-equal-to 3sigma(I)). The structure was sol ved by direct methods, and least-squares refinement converged at R = 0 .037.