New copper complexes of diacetyl hydrazone oxime and its acetone azine

Using diacetyl hydrazone oxime (LH), we have synthesised a neutral copper(I ) complex of the type Cu(L)(LH). Such stabilisation of copper(I) has not be en achieved using the acetone azine (L'H) of LH. Both LH and L'H yield hexa nuclear copper(II) complexes - Cu6L6(O)(OH)(ClO4)(3). 3CH(3)COOH (1a) and C u6L6'(O)(OH)(ClO4)(3) (1b), respectively. X-ray crystal structure of 1b (sp ace group PbcZ(1); Z = 4) indicates that both 1a and 1b contain an unpreced ented Cu3O . . .H . . . OCu3 core where the copper atoms are staggered. In Ib, two of the three perchlorate anions are coordinated to the metals. The cationic part in 1b comprises two [(ClO4)Cu3O(L')(3)] units held together b y a proton. The O . . .H . . .O bond (2.428 Angstrom) is one of the shortes t II-bonds known. Each copper(II) center in 1b is square pyramidal with a p erchlorato oxygen occupying the apical position. The average bond distances around each copper(II) center are: Cu-perchlorato O, 2.54; Cu-central O, 1 .91; Cu-oximato O, 1.92; Cu-oximato N, 1.95; Cu-azine N, 1.98 A. In a [(ClO 4)Cu3O(L')(3)] unit, the three copper atoms are linked to each other via a centrally bridging oxygen atom and two adjacent copper atoms are further li nked by a peripheral oximato bridge. It is indicated that the hexanuclear c opper(II) moiety in 1a and 1b represents a case of two unpaired spins inter acting through an H-bond.