Binuclear Fulvalene and Bis(cyclopentadienyl)methane Halfsandwich Complexes of Manganese and Rhenium Containing Tetrahydrothiophene Ligands. X-Ray Structure Analysis of {(CO)2Mn[C5H4-C5H4]Mn(CO)2}(μ-SC4H8)

The photo-induced substitution of carbonyl ligands in the binuclear cyclopentadienyl-type complexes (CO)3M[C5H4(CH2)nC5H4]M(CO)3 (n = 0 (fulvalene), M = Mn (1) and Re (2); n = 1 (bis(cyclopentadienyl)methane), M = Mn (3) and Re (4)) has been studied in the presence of tetrahydrothiophene, SC4H8 (tht). Photodecarbonylation of 1 - 4 in tetrahydrofuran solution leads to solvent-stabilized intermediates which react with tht in the dark to give monosubstituted derivatives (CO)3M[C5H4(CH2)nC5H4]M(CO)2(tht) (1a - 4a). In the case of M = Mn, thtbridged compounds {(CO)2Mn[C5H4(CH2)nC5H4]Mn(CO)2}(μ-tht) (n = 0 (1b) and n = 1 (3b)) are also obtained which are the exclusive products of the photolysis of 1 and 3 in benzene in the presence of tht. Photodecarbonylation of 1 - 4 in neat tetrahydrothiophene produces disubstituted derivatives in the case of manganese, (tht)(CO)2Mn[C5H4(CH2)nC5H4]Mn(CO)2(tht) (n = 0 (1c) and n = 1 (3c)), whereas only the monosubstituted complexes 2a and 4a could be isolated in the case of rhenium. The molecular structure of the tht-bridged fulvalene complex 1b has been determined by an X-ray structure analysis. A special reaction of dimethyl disulfane with the photolyzed tetrahydrofuran solution of 2 leads to the bis(methylthiolato) compound (CO)3Re[C5H4- C5H4]Re(CO)(SMe)2 (5). The new complexes were characterized by their IR spectra v(CO) and their 1H and 13C NMR spectra.