Reactions of co-ordinated ligands. Part 32. The reaction of sulphur nucleophiles with cationic molybdenum alkyne complexes: alkyne rotation and the molecular structures of the complexes [Mo(SC6H4NO2-p){P(OMe)3}(η2-MeC2Me)(η-C5H5)] and [Mo(SC6H4SPh-o)(CO)(η2-MeC2Me)(η-C5H5)]
Allen, Stephen R.; Glauert, Timothy H.; Green, Michael; Mead, Kevin A.; Norman, Nicholas C.; Orpen, A. Guy; Schaverien, Colin J.; Woodward, Peter
Журнал:
Journal of the Chemical Society, Dalton Transactions
Дата:
1984
Аннотация:
Treatment of [Mo{P(OMe)3}2(η<sup>2</sup>-MeC2Me)(η-C5H5)][BF4] with NaSR (R = Me, p-NH2C6H4, p-MeOC6H4, p-MeC6H4, C6H5, or p-NO2C6H4) leads to displacement of P(OMe)3 and formation of [Mo(SR){P(OMe)3}(η<sup>2</sup>-MeC2Me)(η-C5H5)]. Similar reactions afforded [Mo(SePh){P(OMe)3}-(η<sup>2</sup>-MeC2Me)(η-C5H5)] and [Mo(SMe){P(OMe)3}(η<sup>2</sup>-Bu<sup>t</sup>C2H)(η-C5H5)]. Barriers to rotation of the but-2-yne ligand present in these complexes are related to electronic effects of the substituents on the thiolate ligand. The molecular structure of [Mo(SC6H4NO2-p){P(OMe)3}(η<sup>2</sup>-MeC2Me)-(η-C5H5)] has been established by single-crystal X-ray crystallography. Crystals are monoclinic, space group P21/n with a= 8.968(3), b= 20.104(9), c= 11.452(5)à , β= 95.77(3), and Z= 4. Using 3 601 reflections measured on a four-circle diffractometer at 200 K, the structure has been refined to R 0.028, Râ ² 0.032. The molecule adopts the familiar three-legged piano stool geometry, in which the but-2-yne ligand is orientated such that the central Câ C bond lies approximately parallel to the Moâ P vector. In contrast, [Mo(CO)(η<sup>2</sup>-MeC2Me)2(η-C5H5)][BF4] reacts with NaSMe to give the complexes [Mo(SMe)(CO)(η<sup>2</sup>-MeC2Me)(η-C5H5)] and [Mo2(CO)4(µ-MeC2Me)(η-C5H5)2], whereas the corresponding reaction with [Mo(NCMe)(η<sup>2</sup>-MeC2Me)2(η-C5H5)][BF4] affords [Mo(SMe)-(η<sup>2</sup>-MeC2Me)(η-C5H5)]. Reaction of sodium dimethyldithiocarbamate with [Mo(NCMe)(R<sup>1</sup>C2R<sup>2</sup>)2-(η-C5H5)][BF4](R<sup>1</sup>= R<sup>2</sup>= Me or R<sup>1</sup>= Bu<sup>t</sup>, R<sup>2</sup>= H) gives the monoalkyne complexes [Mo(S2Câ NMe2)(η<sup>2</sup>-R<sup>1</sup>C2R<sup>2</sup>)(η-C5H5)]. In contrast the anion [SC6H4SPh-o]<sup>â </sup> affords a separable mixture of [Mo(SC6H4SPh-o)(η<sup>2</sup>-R<sup>1</sup>C2R<sup>2</sup>)2(η-C5H5)] and [[graphic omitted]Ph-o)(η<sup>2</sup>-R<sup>1</sup>C2R<sup>2</sup>)(η-C5H5)]. Reaction of the S,Sâ ²-bidentate species with carbon monoxide gives [Mo(SC6H4SPh-o)(CO)(η<sup>2</sup>-MeC2Me)-(η-C5H5)], which was structurally identified by X-ray crystallography. Crystals are orthorhombic, space group P212121(no. 19) with Z= 4 in a unit cell of dimensions a= 9.852(3), b= 11.486(4), and c= 18.476(6)à . From 1 714 independent intensities measured at 292 K the structure has been refined to R 0.059, Râ ² 0.041. The molecule adopts a piano stool geometry with the but-2-yne lying parallel to the Moâ CO vector. The dithioaryl ligand is monodentate.
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