81554-96-3Relevant academic research and scientific papers
New hydride, alkyl, aryl, halide, alkene, alkyne, acetylide, and vinylidene members of the (η5-C5Me5)Os(CO)(L)X family. Crystal and molecular structures of [(η5-C5Me5)Os(CO)3][BF 4] and [(η5-C5Me5)Os(CO)(PPh 3)(=C=C(t-Bu)H)][BF4]
Pourreau, Daniel B.,Geoffroy, Gregory L.,Rheingold, Arnold L.,Geib, Steven J.
, p. 1337 - 1345 (2008/10/08)
The photochemical reaction of Cp*Os(CO)2I (1, Cp* = η5-C5Me5) with PMe3 or PPh3 under CO pressure gave substitution of 1- by PR3 to form the salts [Cp*Os(CO)2(PR3)][I]. Reaction of these salts with Me3NO afforded the neutral complexes Cp*Os(CO)(PR3)I (7, L = PMe3, and 8, L = PPh3) in good yield. The new alkyl complexes Cp*Os(CO)LR (L = CO, R = Me, 3; L = CO, R = Bu, 2; L = PMe3, R = Me, 11) derived from reaction of 1 and 7 with the appropriate RLi reagent. Complex 11 was also obtained directly from [Cp*Os(CO)2(PMe3)]I by NaBH4 reduction of a coordinated CO. The phenyl complex Cp*Os(CO)2Ph was obtained by sequential treatment of 1 with AgBF4 and PhLi or by photoassisted C-H activation of benzene with 3. Irradiation of Cp*Os(CO)2CH3 in the presence of CH2=CH2 gave the new ethylene-methyl complex Cp*Os(CO)C2H4)(CH3), Rotation of the C2H4 ligand in this complex was characterized by a variable-temperature NMR study. Treatment of Cp*Os(CO)(PPh3)I with AgBF4 followed by diphenylacetylene gave the η2-alkyne complex [Cp*Os(CO)(PPh3)(PhC≡CPh)][BF4]. When terminal alkynes were used in this latter reaction, the stable vinylidene complexes [Cp*Os(CO)(PPh3)(=C=CHR)]+BF4 (R = t-Bu, Ph) were obtained. The structure of [Cp*Os(CO)(PPh3)(=C=C(t-Bu)H)][BF4] (14) was confirmed by an X-ray diffraction study: P1 with a = 10.444 (2) A?, b = 12.091 (2) A?, c = 14.793 (4) A?, α = 97.49 (2)°, β = 109.28 (2)°, γ = 101.64 (2)°, V = 1687.4 (7) A?3, Z = 2, R = 3.42%, Rw = 3.58% for the 5595 reflections with Fo ≥ 2.5σ(Fo). In contrast, treatment of 1 with AgBF4 followed by HC≡C-t-Bu or other terminal alkynes gave a mixture of [Cp*Os(CO)3][BF4] (17) and another unidentified organometallic complex. Complex 17 was crystallographically characterized: Pbcm with a = 10.396 (2) A?, b = 13.008 (3) A?, c = 12.123 (2) A?, V= 1639.4 (6) A?3, Z = 4, R = 5.44%, Rw = 5.65% for the 1521 reflections with Fo ≥ 3σ(Fo).
