Übergangsmetallkomplexe mit Schwefelliganden: XXX. Struktur, stereoisomerie und reaktivität von eisen-, molybdän- und ruthenium-komplexen mit den fünfzähnigen thioether-thiolat-liganden dpttd2 = 2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecan(−2) und tbu4-dpttd2− = 14,16,18,20-tetra-t-butyl-2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecan(−2)

Abstract

meso-[Fe(CO)(dpttd)] (dpttd2− = 2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) can be isolated by fractional crystallization from a mixture of diastereomers of [Fe(CO)(dpttd)] and was characterized by X-ray structure analysis. The Fe center in meso-[Fe(CO)(dpttd)] is pseudo-octahedrally coordinated by one C and five S atoms and contains a mirror plane. The t-butyl derivative of dpttd-H2, the sterically demanding pentadentate thioether thiolate [tbu4-dpttd]2− (= 14,16,18,20-tetra-t-butyl-2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) coordinates to Fe, Ru and Mo centers yielding mixtures of diastereomeric complexes. Thus FeCl2·4H2O reacts with Na2[tbu4-dpttd)] to give diastereomers of [Fe(tbu4-dpttd)], which coordinate CO to give three diastereomers of [Fe(CO)(tbu4-dpttd)], two of which could be separated. One of these was unambiguously identified by 1H NMR spectroscopy to be meso-[Fe(CO)(tbu4-dpttd)]. meso-[Fe(CO)(tbu4-dpttd)] reacts with NO+ retaining its configuration to yield meso-[Fe(NO)(tbu4-dpttd)]+; a reaction mechanism via thionitrosylation of a thiolate S atom of the tbu4-dpttd2− ligand is proposed. The reaction of [MoCl4(THF)2] with tbu4-dpttd-H2 and H2O yields a mixture of diastereomers of [MoO(tbu4-dpttd)], from which meso-[MoO(tbu4-dpttd)] is isolated by fractional crystallization. Reaction of RuCl3(NO)·χH2O and [RuCl3(PhSCH3)3] with tbu4-dpttd2− yields mixtures of diastereomers of [Ru(NO)(tbu4-dpttd)]+ and [Ru(Cl)(PhSCH3)(tbu4-dpttd)]2, respectively; the latter is reduced by Zn to give [Ru(PhSCH3)(tbu4-dpttd)].