Metallathiirenes. 4. Thioaroyl complexes of molybdenum(II) and tungsten(II)

Synthetic routes to a range of thioaroyl complexes of tungsten and molybdenum are reported. Successive treatment of [M(CO)(6)] (M = Mo, W) with LiC6H4OMe-4.LiBr, (CF3CO)(2)O, and 2,2-bipyridyl (bipy) provides [M(equivalent toCC(6)H(4)OMe-4)Br(CO)(2)(bipy)], which react with methylthiirane to provide the thioaroyl complexes [M(eta(2)-SCC6H4OMe-4)Br(CO)(2)(bipy)] and the dithiocarboxylate complexes [M(eta(2)-S2CC6H4OMe-4)Br(CO)(2)(bipy)]. [Mo(equivalent toCC(6)H(4)Me-4)(CO)(2){HB(pz)(3)}] (pz = pyrazol-1-yl), [Mo(equivalent toCC(6)H(4)OMe-4)(CO)(2){HB(pz)(3)}] (obtained from [Mo(=CC6H4OMe-4)Br(CO)(2)(gamma-picoline)(2)] and K[HB(pz)(3)]), and [MO(equivalent toC(4)H(3)S-2)(CO)(2){HB(pz)(3)}] (obtained directly from [MO(CO)(6)], 2-thienyllithium, (CF3CO)(2)O, and K[HB(pz)(3)]) react with methylthiirane to provide primarily [Mo(eta(2)-SCR)(CO)(2){HB(pz)(3)}] in addition to small amounts of the corresponding dithiocarboxylates [Mo(eta(2)-S2CR)(CO)(2) HB(pz)(3)}], which also arise from treatment of [Mo(eta(2)-SCR)(CO)(2){HB(pz)(3)}] with methylthiirane or elemental sulfur. [Mo(= CC6H2Me3-2,4,6)(CO)(2){HB(pz)(3)}] failed to react with methyllirane, while [MO(equivalent toCC(6)H(4)OMe-4)(CO)(2)(eta-C5H5)] provided exclusively the dithiocarboxylate derivative. The mixed selenothiocarboxylates [Mo(eta(2)-SSeCR)(CO)(2) HB(pz)(3)}] (R = C6H4OMe-4, C4H3S-2) are obtained by treating [Mo(eta(2)-SCR)(CO)(2){HB(pz)(3)}] with Li2Se2, while [Mo(eta(2)-SOCC6H4Me4)(CO)(2){HB(pz)(3)}] results from hydrolysis of the product of the reaction of [Mo(eta(2)-SCC6H4Me-4)(CO)(2){HB(pz)(3)}] with [Me2SSMe]BF4. Alkylation of [Mo(eta(2)-SCC6H4Me-4)(CO)(2) HB(pz)(3)}] With [Et(3)o]BF4 provides the thiolatocarbene salt [Mo(eta(2)-EtSCC6H4Me-4)(CO)(2){HB(pz)(3)}], while the analogues [Mo(eta(2)-MeSCC6H4Me-4)(CO)(2){HB(pz)(3)}]BF4 and [Mo(eta(2)-MeSCC4H3S2)(CO)(2){HB(pz)(3)}]BF4 result from the reactions of [Mo(equivalent toCR)(CO)(2){HB(pz)(3)}] with [Me2SSMe]BF4. The reactions of these salts with the nucleophiles Li[Et3BH] and Me3CSH provide the thioalkyl complexes [Mo(eta(2)-MeSCHC4H3S-2)(CO)(2){HB(pz)(3)}], [Mo(eta(2)-MeSCHC(6)H(4)oMe-4)(CO)(2)}HB(pz)(3)}], and [Moeta(2)-MeSC(SCMe3)C6H4OMe-4)(CO)(2){HB(pz)(3)}]. The heterobimetallic thioaroyl complex [MoFe(mu-SCC6H4Me-4)(CO)(5){HB(pz)(3)}] is obtained from the reaction of [Mo(eta(2)-SCC6H4Me-4)(CO)(2){HB(pz)(3)}] with [Fe-2(CO)(9)].