Transition metal complexes with sulfur ligands. XXVIII. Ruthenium complexes of the pentadentate thioether thiolate ligands dpttd 2− (2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) and the sterically demanding derivative tbu 4-dpttd 2− (14,16,18,20-tetra (t-butyl)-2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2))

Abstract

The template alkylation of Li 2[Ru(CO) 2(S 2C 6H 4) 2] (S 2C 6H 4 2− = 1,2-benzenedithiolate(−2)) by S(C 2H 4Br) 2 yields [Ru(CO) 2(dpttd)] (dpttd 2− = 3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) which is thermally converted into the monocarbonyl complex [Ru(CO)(dpttd)]. The reactions of dpttd-H 2 or dpttd 2− with [RuCl 2(PPh 3) 3], [RuCl 2(DMSO) 4], [RuCl 3(PhSCH 3) 3] and RuCl 3(NO)· xH 2O lead to [Ru(L)(dpttd)] and [Ru(L)(dpttd)]Cl (L = PPh 3, DMSO, PhSCH 3, NO), respectively, which are practically insoluble in all common solvents. Better soluble complexes are obtained with the new sterically demanding ligand tbu 4-dpttd 2− = 14,16,18,20-tetra(t-butyl)-2,3,11,12-dibenzo-1,4,7, 10,13-pentathiatridecane(−2); it is obtained in isomerically pure form by the reaction of tetrabuthylammonium-3,5-di (t-butyl)-1,2-benzenethiolthiolate, NBu 4[ tbu 2-C 6H 2S(SH), with S(C 2H 4Br) 2 and yields on reaction with [RuCl 2(PPh 3) 3] the very soluble [Ru(PPh 3) 2( tbu 4-dpttd)] as well as [Ru(PPh 3( tbu 4-dpttd)]. The 1H NMR and 31P NMR spectra indicate that in solution [Ru(PPh 3) 2( tbu 4-dpttd)] exists as a mixture of diastereomers, whereas [Ru(PPh 3)( tbu 4-dpttd)] forms one pair of enantiomers only. This was confirmed by an X-ray structure determination of a single crystal. [Ru(PPh 3)( tbu 4-dpttd)] crystallizes in space group P2 1/ n with a = 10.496(4), b = 14.888(6), c = 32.382(12) Å, β = 98.04(3)°, Z = 4 and D calc. = 1.27 g/cm 3, R = 4.84; R W = 5.06%; the ruthenium center is coordinated pseudooctahedrally by one phosphorus, two thiolate and three thiother S atoms.