METAL-COMPLEXES OF SULFUR-CONTAINING LIGANDS - SYNTHESIS AND PROPERTIES OF A SERIES OF RHENIUM-SUBSTITUTED SULFONIUM SALTS [(ETA-5-C5H5)RE(NO)(PPH3)(CH2-)]NS+(CH3)3-N(N=1-3)
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Reaction of [(5-C5H5)Re(NO)(PPh3)(=CH2)]+PF6- (1, -78 C) with CH3SCH3 gives sulfonium salt [(5-C5H5)Re(NO)(PPh3)(CH2S(CH3)2)]+PF6- (2, 90-95%). Variable-temperature NMR data show that CH3SCH3 reversibly gives from 2 with G*262= 14.2 kcal/mol and G*289 = 12.9 kcal/mol. Reaction of 2 with PPh3 and pyridine give [(5-C5H5)Re(NO)(PPh3)(CH2PPh3)]+PF6- (4, 76%) and [(5-C5H5)Re-(NO)(PPh3)(CH2N(CH)4CH)]+PF6- (5), respectively. Reaction of 2 with RS- gives (5-C5H5)Re(NO)-(PPh3)(CH2SR) (6, 79-95%; R = CH3(a), C6H5 (b), CH2C6H5 (c)). Reaction of 1 or 2 with 6a gives binuclear sulfonium salt [(5-C5H5)Re(NO)(PPh3)(CH2-)]2S+CH3PF6- (7+PF6-, 89-92%) as a 2:1:1 mixture of dia-stereomers. Treatment of 7+PF6- with NaI/CH3CN gives 7+I-, which crystallizes as one diastereomer as shown by X-ray crystallography. Crystal data: orthorhombic, Pnma; a = 18.348 (6) ,b = 20.767 (2) , c = 13.944 (2) ; Z = 4. Reaction of 7+PF6- with PPh3 gives 4 (90%) and 6a (71%). Pyrolysis of 7+PF6- (80 C, 8 h) gives (5-C5H5)Re(NO)(PPh3)(CH3) (8, 84%) and [(5-C5H5)Re(NO)(PPh3)(=CHSCH3)]+PF6-(9, 82%). Reaction of 1 with Na2S gives trinuclear sulfonium salt [(5-C5H5)Re(NO)(PPh3)(CH2-)]3S+PFe- (10, 84%). Complex 10 reacts only sluggishly with PPh3 (65 C). These reactions show that the (5-C5H5)Re(NO)(PPh3) moiety significantly enhances the basicity of sulfide sulfur atoms that are to it. 1986, American Chemical Society. All rights reserved.
