THE BIDENTATE BONDING MODE OF BIS[2-OXIMINOCYANACETAMIDATO(2-)-N,N]NICKELATE(II) ANION TOWARDS TETRAPHENYLANTIMONY(V) - UNUSUALLY LONG SB-OCONTACT

The heteronuclear complex of tetraphenylantimony(V) with anion of bis( oximino-cyanoacetamidato(2-)-N,N)nickelate(II) [(Ph4Sb)(2){Ni(NCC(NO)C (O)NH)(2)}] 1 was synthesized and investigated by single crystal X-ray analysis. 1 was isolated as a;result of the reaction between tetraphe nylantimony(V) chloride and nickel(II) complex with (hydroximino)cyano acetamide (H(2)aco) Na-2{Ni(aco)(2)} obtained by reaction of Ni(Haco)( 2) with NaOH. The crystal comprises heterometal centrosymmetric molecu les (Ph4Sb)(2){Ni(aco)(2)}. The Ni atom is in a slightly distorted squ are planar surrounding formed by the four nitrogen atoms of deprotonat ed hydroximino and amide groups (Ni-N-oxime 1.890(4), Ni-N-amide 1.862 (4) Angstrom). The ligands are situated in trans positions with respec t to each other. The coordination environment of the antimony atom in the Ph4Sb+ cation is somewhat distorted trigonal bipyramidal [SbC4O], Sb-C-eq 2.084(5)-2.108(5) Angstrom. All angles C-eq-Sb-O-ax are less t han 90 degrees. Ph4Sb+ coordinates to the oxygen atom of C=O group (Sb -O 2.647(3) Angstrom). The geometrical parameters of the CNO group ind icate that it exists in the nitroso-form. (C) 1998 Elsevier Science Lt d. All rights reserved.