Synthetic and Computational Studies on the Thermal and Photochemical Reactions of [NPN]TaMe3 (NPN = PhP(CH2SiMe2NPh)2) and [MesNPN]TaMe3 (MesNPN = PhP(CH2SiMe2N(2,4,6-Me3C6H2))2)

Autor: Richard J. Burford, Aleksandra Zydor, Michael D. Fryzuk
Rok vydání: 2017
Předmět:
Zdroj: Organometallics. 36:3564-3572
ISSN: 1520-6041
0276-7333
DOI: 10.1021/acs.organomet.7b00487
Popis: The thermolysis of [PhP(CH2SiMe2NPh)2]TaMe3 leads to the elimination of methane and the formation of cyclometalated derivative [PhP(CH2SiMe2NPh)(CH2SiMe2N-o-C6H4)]TaMe2, which was characterized by NMR spectroscopy and single crystal X-ray analysis. Computational studies confirm the expected four-membered transition state involving an ortho-N-phenyl-C–H bond and a Ta-methyl unit. The photolysis of [PhP(CH2SiMe2NPh)2]TaMe3 takes a different course; loss of methane also occurs but results in the formation the methylidene complex, [PhP(CH2SiMe2NPh)2]Ta═CH2(Me), which was characterized by NMR spectroscopy. Attempts to block the cyclometalation process by replacement of the N-phenyl substituent with N-Mesityl (Mesityl = 2,4,6-Me3C6H2) is also reported. With this bulkier ancillary ligand, the reactions are more complicated with multiple products being observed in an overall slow process. The reactions of the trimethyl, the cyclometalated product and the methylidene with H2 were also investigated and found to exh...
Databáze: OpenAIRE