101009-37-4Relevant articles and documents
Syntheses, spectral properties, and substitution reactions of M(CO)3(S2CNC4H4)2 (M = Mo, W) complexes containing the electronically unique pyrrole-N-carbodithioate ligand
Herrick, Richard S.,Templeton, Joseph L.
, p. 1270 - 1276 (2008/10/08)
A series of seven-coordinate M(CO)3-nLn(S2CNC4H4) 2 (n = 0-2) molybdenum(II) and tungsten(II) complexes have been synthesized with the electronically unique pyrrole-N-carbodithioate chelating ligand [M(CO)2L(S2CNC4H4)2: M = Mo, W, L = PPh3, PEt3, P(OMe)3; M = Mo, L = OC4H8, SC4H8, AsPh3, SbPh3. M(CO)L2(S2CNC4H4)2: M = Mo, W, L = P(OMe)3; M = Mo, L = PEt3, 1/2 Ph2PCH2CHPPh2. [R4N] [M(CO)2X(S2CNC4H4)2]: M = Mo, W, X = F; M = Mo, X = Cl, Br, I]. The decreased electron donor ability of the pyrrole-N-carbodithioate ligand relative to alkyl analogues is evident in increased infrared vco frequencies and in increased lability of carbon monoxide ligands in M(CO)3-nLn(S2CNC4H4)2 complexes with n = 0 and 1. The 16-electron Mo(CO)2(S2CNC4H4)2 complex is significantly more electrophilic than Mo(CO)2(S2CNEt2)2 as reflected in isolation of the stable halide complexes listed above. Carbon-13 enriched carbon monoxide ligands in W(CO)3(S2CNC4H4)2 and W(CO)2(PPh3)(S2CNC4H 4)2 have been used to probe intramolecular rearrangements by variable-temperature 13C NMR. Two low-temperature fluxional processes are observed for the parent tricarbonyl; the first exchanges two of the three inequivalent carbonyl ligands, and the second averages all three carbonyl signals. The (triphenylphosphine)tungsten derivative exhibits a single carbon monoxide 13C NMR signal at room temperature, which is frozen into two signals at low temperature.
