Intramolecular hydride migration from formyl to carbonyl and nitrene ligands
- Univ. of North Carolina, Chapel Hill, NC (United States)
Reaction of [Tp{prime}W(CO){sub 2}(NPh)][PF{sub 6}] [Tp{prime} = hydrotris(3,5-dimethylpyrazolyl)borate] with lithium borohydride at -40 {degrees}C generates Tp{prime}W(CO)(Nph)(CHO) (1), which undergoes hydride migration from carbon to nitrogen (at -70 {degrees}C, k{sub obs} = 7.2 x 10{sup -6} s{sup -1}, {Delta}G{sup {double_dagger}} = 16.5 kcal/mol, t{sub {1/2}} = 27 h) to form Tp{prime}W(CO){sub 2}(NHPh). Crossover experiments indicate that the hydride migration is intramolecular. The metal formyl intermediate is fluxional; hydride migration interconverts the formyl and carbonyl ligands. The rate constant for this degenerate migration is 40 s{sup -1} at -41 {degrees}C with {Delta}G{sup {double_dagger}} = 11.7 kcal/mol. The analogous acyl complex Tp{prime}W(CO)(Nph)[C(O)Ph] (3) has been synthesized from the reaction of [Tp{prime}W(CO){sub 2}-(NPh)][PF{sub 6}] with PhMgBr. 9 refs.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG05-85ER13430
- OSTI ID:
- 539382
- Journal Information:
- Organometallics, Journal Name: Organometallics Journal Issue: 4 Vol. 11; ISSN ORGND7; ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
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