The thermal reactions of the Re(V) dithiolate complex Cp'ReCl2(SCH2CH2S), 1 (where Cp' = EtMe4C5), and related derivatives have been studied. When 1 is heated in toluene in a sealed evacuated tube at 100 degrees C, a dehydrogenation reaction occurs to form a new rhenium complex with a dithiolene ligand, Cp'ReCl2(SCHCHS), 6, in ca. 40% yield. The structure of 6 has been confirmed by an X-ray diffraction study. Under the thermal conditions studied, 1 also undergoes an olefin extrusion reaction. Free ethene is detected in the NMR spectrum of the products, and insoluble rhenium products are also formed. When 1 is reacted with excess ethene under mild conditions, a new organic product, 1,4-dithiane, is formed. Complex 1 is also found to react with oxidants, such as O2 and S8, under mild conditions to form the dehydrogenation product 6. Kinetic studies of the thermal reaction of 1 and related derivatives have been completed, and possible mechanisms for the thermally induced dehydrogenation reaction are discussed.

Ethylene sulfide and propylene sulfide react with the high valent metal complex Cp′ReCl 4 (Cp′ ) EtMe 4 C 5 ) in THF solution to form a product with a chloroalkyl disulfide ligand of the formula Cp′Re(Cl) 3 -S-S-CH(R)CH 2 Cl (R ) H or Me). In contrast, the thietane S(CH 2 ) 3 reacts with Cp′ReCl 4 to form a simple adduct, and no ring-opening reaction has been identified.

The reaction of Cp'ReCl(2)S(3) (Cp' = Me(4)EtC(5)) with slightly less than 2 equiv of a phosphine reagent results in the formation of [Cp'Re(Cl)(2)(mu-S)](2), 2, which has been characterized by an X-ray diffraction study. Reactions of 2 with nucleophiles did not lead to monomeric derivatives of the type Cp'ReS(Cl)(2)(Nuc). The reaction of Cp'ReCl(2)(SC(2)H(4)S) with (Me(3)Si)(2)S resulted in the formation of three new products: Cp'ReS(SC(2)H(4)S), 4; Cp'Re(S(3))(SC(2)H(4)S), 5; and a tetranuclear derivative, [(Cp'Re)(2)(mu-S)(mu,eta(2)-SC(2)H(4)S)(mu,eta(1)-SC(2)H(4)S](2)Cl(2), 6. Complexes 4 and 6 have been characterized by X-ray diffraction studies. The electrochemical properties of the mononuclear Re=S derivative, 4, are compared with those of Re=O and Re=NR analogues.

The syntheses and characterizations of Cp′′ReCl 2 (SC 3 H 6 S), 1, Cp′′ReCl 3 (SCHMe 2 ), 2, and Cp′′ReCl 2 (SCHMe 2 ) 2 , 3, are reported (Cp′′ ) C 5 Me 4 Et). Complex 2 has been characterized by an X-ray diffraction study, which confirms its mononuclear structure. Reactions of 1, 2, and 3 have been studied and compared with those characterized previously for Cp′′ReCl 2 -(SC 2 H 4 S). For example, the thermal reaction of 1 in toluene at 100 °C, results in the elimination of HCl and formation of a complex with a chelated thiolate/thialdehyde ligand, Cp′′ReCl(SCH 2 CH 2 CHdS), 5. Complex 5 can also be synthesized at a lower temperature by the reaction of 1 with excess triethylamine. Spectroscopic characteristics and reactivity of 5 are reported.Supporting Information Available: Tables giving crystal data, positional and thermal parameters, bond distances, and bond angles for 2 and 4, and variable-temperature NMR data for 2. This material is available free of charge via the Internet at http://pubs.acs.org. OM020626T(21) Flack, H. D.