Reactions of dithiolate ligands in mononuclear complexes of rhenium(V).
ABSTRACT 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.
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ABSTRACT: Polyimide membranes containing nickel dithiolenes were investigated for the separation of propylene and propane. Permeation and sorption experiments were conducted as well thermal property analyses. Results indicate that the dithiolene has an antiplasticizing effect on the polymers studied. Upon addition of the dithiolene there is a subsequent reduction in the permeability coefficient and the permeability selectivity remains relatively unchanged. There is some evidence of increases in solubility selectivity, but a larger decrease in diffusivity selectivity results in a decrease in the permeability selectivity. Investigation of the thermal and mechanical properties of dithiolene-containing films indicates a reduction in fractional free volume as well as the glass transition temperature when compared to the pure polymer. There is also an increase in the modulus of the films upon addition of the dithiolene. The implications of these results and their correlation with antiplasticization are discussed. Ph.D. Committee Chair: Koros, William; Committee Member: Jones, Christopher; Committee Member: Kumar, Satish; Committee Member: Ludovice, Pete; Committee Member: Nair, Sankar
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ABSTRACT: The syntheses and characterizations of Cp‘ ‘ReCl2(SC3H6S), 1, Cp‘ ‘ReCl3(SCHMe2), 2, and Cp‘ ‘ReCl2(SCHMe2)2, 3, are reported (Cp‘ ‘ = C5Me4Et). 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‘ ‘ReCl2(SC2H4S). 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(SCH2CH2CHS), 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.Organometallics 01/2003; 22(1):111-117. DOI:10.1021/om020626t · 4.25 Impact Factor
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ABSTRACT: The reaction of Cp'ReCl2S3 (where Cp'=C5EtMe4) with Pt(PPh3)3 in toluene in air results in the formation of the heteronuclear product [Cp'ReO(μ3-S)2Pt2(PPh3)3Cl]ReO4, 1. The product has been characterized by spectroscopic methods, cyclic voltammetry and by an X-ray diffraction study. The cation contains an unusual triangular array of one rhenium and two platinum ions with one Pt-Re bond. Under the same reaction conditions, the reaction of the known platinum dimer (PPh3)4Pt2(μ-S)2 with Cp'ReOCl2 was unsuccessful as a route to the cation of 1.Journal of Coordination Chemistry 01/2003; 56(1-1):41-47. DOI:10.1080/0095897021000039089 · 2.22 Impact Factor