TRANSITION-METAL COMPLEXES WITH SULFUR LIGANDS .85. [NI(TERT-BU-S4-C2')]3, A NEW TYPE OF TRINUCLEAR NI COMPLEXES (TERT-BU-S4-C2' = 1,2-BIS(3,5-DITERTIARYBUTYL-2-MERCAPTOPHENYLTHIO)ETHANE(2-))

Ni(II) salts and the tetradentate thioether-thiolate ligand 'S4-C2'2- (= 1,2-bis(2-mercaptophenylthio)ethane(2-)) yield [Ni('S4-C2')]x (1), that also forms when Na2[Ni('S2')2] ('S2'2- = o-benzenedithiolate(2-)) is alkylated by 1,2-dibromoethane. In boiling pyridine 1 adds two solvent molecules and gives pseudooctahedral [Ni(pyr)2('S4-C2')] (2) which was characterized by X-ray structure determination. Reaction of 1 with PMe3 yields [Ni(PMe3)('S4-C2')] (4). X-ray structure determination of 4 showed that the Ni center is surrounded by one P and four S atoms in a distorted tetragonal pyramid in which the P atom, one thioether S atom and both of the thiolate S atoms form the base while the second thioether S atom occupies the apical position. Reaction of 1 with n-BuLi leads to removal of the C2H4 bridge of the 'S4-C2'2- ligand and formation of Li2[Ni('S2')2]. When [Ni(acac)2]3 is reacted with '(bu)S4-C2'2- (= 1,2-bis(3,5-ditertiarybutyl-2-mercaptophenylthio)ethane(2-)) which is analogous to 'S4-C2'2-, the trinuclear [Ni('(bu)S4-C2')]3 (3) forms. 3.THF was characterized by X-ray structure determination. It contains one tetrahedrally distorted and two planar [NiS4] cores that are connected via the C2H4 groups of the ligands such that a macrocycle forms. PMe3 cleaves 3 to give mononuclear [Ni(PMe3)('(bu)S4-C2')] (5). Due to its lability, it was characterized only by spectroscopic methods.