| Abstract
| - Synthetic routes are reported to a range of thiocarbamoyl complexes of molybdenum and tungsten via oxidative addition of N,N-dimethylthiocarbamoyl chloride, followed by ligand substitution. From a similar strategy, aryloxythiocarbonyl complexes of molybdenum are also described.
- Synthetic routes to thiocarbamoyl (thiocarboxamide) complexes of divalent molybdenumand tungsten are reported: The reaction of fac-[Mo(CO)3(NCMe)3] with N,N-dimethylthiocarbamoyl chloride (Me2NC(S)Cl) at low temperature provides a thermally labileintermediate (1) presumed on the basis of subsequent transformations to be [Mo(η2-SCNMe2)Cl(CO)3(NCMe)]. Reactions of 1 with K[HB(pz)3] (pz = pyrazol-1-yl), NaC5H5, bipy, or tmedaprovide the complexes [Mo(η2-SCNMe2)(CO)2{HB(pz)3}] (2), [Mo(η2-SCNMe2)(CO)2(η-C5H5)](3), [Mo(η2-SCNMe2)Cl(CO)2(bipy)] (4), and [Mo(η2-SCNMe2)Cl(CO)2(tmeda)] (5), respectively.The complex cis,cis,trans-[Mo(η2-SCNMe2)Cl(CO)2(PPh3)2] (6) results from the oxidativeaddition of Me2NC(S)Cl to [Mo(NCMe)2(CO)2(PPh3)2] and is one of two isomers obtainedfrom the reaction of 1 with PPh3. The complex 2 may also be obtained from reaction of (i)K[Mo(CO)3{HB(pz)3}] with Me2NC(S)Cl; (ii) [Mo(CO)3(η6-C7H8)] with Me2NC(S)Cl andK[HB(pz)3]; and (iii) K[HB(pz)3] with either 5 or 6. Sequential treatment of either [Mo(CO)3(NCMe)3] or [Mo(CO)3(η6-C7H8)] with ClC(S)OR (R = C6H4Me-4, C6H5) and K[HB(pz)3]provides the complexes [Mo(η2-SCOR)(CO)2{HB(pz)3}] [R = C6H4Me-4 (7a), C6H5 (7b)].Attempts to prepare a mononuclear thiocarbamoyl complex by addition of elemental sulfuror propene episulfide to the aminomethylidyne complex [Mo(⋮CNiPr2)(CO)2{HB(pz)3}] (8)were unsuccessful; however addition of [Fe2(CO)9] to 8 provided the thermally unstablecomplex [MoFe(μ-CNiPr2)(CO)5{HB(pz)3}] (9), which reacts with sulfur to provide theheterobimetallic bridging thiocarbamoyl complex [MoFe(μ-SCNiPr2)(CO)5{HB(pz)3}] (10).Treating fac-[W(CO)3(NCMe)3] sequentially with Me2NC(S)Cl and K[HB(pz)3] provided[W(η2-SCNMe2)(CO)2{HB(pz)3}] (11); however replacing Me2NC(S)Cl with ClC(S)OC6H4Me-4 led to [WCl(CO)3{HB(pz)3}] (12).
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