184875-97-6Relevant academic research and scientific papers
Synthesis and nuclear magnetic resonance studies of molybdenum and tungsten thiolate complexes
Davidson, Jack L.,Holz, Birgit,Lindsell, W. Edward,Simpson, Nigel J.
, p. 4011 - 4017 (2007/10/03)
Reactions of [WCl3(CO)2(η5-C5H5)] with Tl[SC6F4H-4] and [WBr3(CO)2(η5-C5H5)] with Tl[SR] (R = Ph or C6H4Me-4) in dichloromethane gave tungsten(IV) compounds [W(SPh)3(CO)(η5-C5H 5)]·0.25CH2Cl2 1a, [W(SC6H4Me-4)3(CO)(η5-C 5H5)] 1b and [W(SC6F4H-4)3(CO)(η5-C 5H5)] 1c, respectively. Reaction of [MoCl(CO)3(η5-C5H5)] with 2 molar equivalents of Tl[SC6F4H-4] in diethyl ether gave a mixture of [Mo(SC6F4H-4)(CO)3(η5-C 5H5)] 2 and Tl[Mo(SC6F4H-4)2(CO)2(η5-C 5H5)] 3. The photochemical reaction of Tl[Mo(SC6F4H-4)2(CO)2(η 5-C5H5)] and (SC6F4H-4)2 in tetrahydrofuran (thf) afforded Tl[Mo(SC6F4H-4)4(η5-C 5H5)] 4a whilst [WBr3(CO)2(η5-C5H5)] and 5 equivalents of Tl[SC6F4H-4] gave Tl[W(SC6F4H-4)4(η5-C 5H5)] 4b. These were converted into [N(PPh3)2][M(SC6F4H-4) 4(η5-C5H5)] (M = Mo or W) on reaction with [N(PPh3)2]Cl. Reactions of [W(SC6F4H-4)3(CO)(η5-C 5H5)] with alkali-metal derivatives M′[SC6F4H-4] in thf afforded M′[W(SC6F4H-4)4(η5-C 5H5)] (M′ = K 4c, Rb 4d or Cs 4e). With M′ = Na the tetrathiolate complex was obtained as a thf solvate Na[W(SC6F4H-4)4(η5-C 5H5)]-thf 5. Fluorine-19 NMR spectroscopy revealed that 1c and 3-5 undergo several dynamic processes, viz. fluxional behaviour involving rotation/inversion of the SC6F4H-4 groups. The spectra of the thallium and caesium derivatives {and 133Cs spectra in the case of Cs[M(SC6F4H)4(η5-C 5H5)]} in addition show coupling between the metal M′ and four of the o-fluorines of the SC6F4H-4 groups at low temperatures providing evidence for reversible co-ordination between the M′+ cation and the organometallic anion. This behaviour is solvent dependent, occurring more readily in more polar solvents.
