DIMERIC NICKEL(II) CARBOXYLATES AND A SILANECARBOXYLATE - [NI(ME3CCOO)2(2,5-LUTIDINE)]2, [NI(MEPH2CCOO)2(QUINOLINE)]2RADICAL-ANION 2CHCL3, [NI(ME2PHCCOO)2(QUINOLINE)]2, [NI(ME3CCOO)2(2-ETHYLPYRIDINE)]2, [NI(ME3CCOO)2(2-PICOLINE)]2 AND [NI(MEPH2SICOO)2(PH3P)]2

The structures of five dimeric Ni(II) carboxylates and one dimeric Ni(II) silanecarboxylate have been determined: (I), tetrakis(mu-2,2-dimethylpropanoato-O,O')-bis(2,5-lutidine)dinickel, [NiC5H9O2)2(C7H9N)]2; (II), tetrakis(mu-2,2-diphenylpropanoato-O,O')-diquinolinedinickel bis-(trichloromethane), [Ni(C15H13O2)2(C9H7N)]2.2CHCl2; (III), tetrakis(mu-2-methyl-2-phenylpropanoato-O,O')-diquinolinedinickel, [Ni(C10H11O2)2(C9H7N)]2; (IV), tetrakis(mu-2,2-dimethylpropanoato-O,O')bil(2-ethyl-pyridine)dinickel, [Ni(C5H7N)]2; (VI), tetrakis (mu-methyl diphenylsilanecarboxylato-O,O')-bis(triphenylphosphine)dinickel, [Ni(C14H13O2Si)2(C18H15P)]2. The Ni atoms are arranged in a square-pyramidal geometry and the Ni2(COO)4 moiety forms a slightly distorted cage structure. The Ni...Ni distances are in the range 2,7079(8)-2.765(1) angstrom.