Promotion of methyl/carbonyl migratory insertion by transition-metal Lewis acids. Synthesis and reactivity of a transition-metal heterobimetallic carbonyl alkyl anion, MeFeW(CO)9-

Structure and Reactivity of Early−Late Heterobimetallic Complexes

“…Direct addition of [FeMe(CO) 4 ] - to [W(CO) 5 (thf)] results in the heterobimetallic anion [(OC) 5 WFeMe(CO) 4 ] - , with the methyl group cis to the tungsten−iron bond …”

Nickel-Containing Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase,

“…An example of catalytic enhancement by Lewis acid activation that may be relevant to CODH and ACS is provided by studies of the octahedral metal complex [MeFeW(CO) 9 2- ] …”

Photochemical Heterolysis of the Metal−Metal Bond in (Me3P)(OC)4OsW(CO)5

“…The electronic absorption spectrum of 1 in the region 300−900 nm exhibits a peak with a maximum at 368 nm (ε = 2.79 × 10 3 ± 1.9 × 10 2 L mol -1 cm -1 ) and a subtle shoulder at 334 nm (ε = 2.7 × 10 3 ± 1.9 × 10 2 L mol -1 cm -1 ) in C 6 H 6 at 25 °C. By analogy to binuclear complexes with unbridged metal−metal bonds, the band at 368 nm is assigned to a σ → σ* transition associated with the metal−metal bond. , For comparison, the [H(OC) 4 FeM(CO) 5 ] - complexes (M = Cr, Mo, W), with a putative donor−acceptor metal−metal bond, also exhibit a strong absorption in the near-UV region (315−330 nm, ε ≈10 4 L mol -1 cm -1 ) …”

“…A possible mechanism for the formation of W(CO) 6 is that it results from CO abstraction by W(CO) 5 from Os(CO) 4 (PMe 3 ) in the geminate caged intermediate [Os(CO) 4 (PMe 3 ), W(CO) 5 ] (Scheme ) . The high reactivity of W(CO) 5 and its ability to abstract ligands from other moieties has ample precedent. 26b,,, To probe this possibility, the photolysis (λ > 400 nm) of 1 (1.22 × 10 -3 M) was repeated in a more viscous medium of biphenyl (2.87 M) in C 6 H 6 at 25 °C (absolute viscosity 1.2 cP as compared to C 6 H 6 absolute viscosity 0.601 cP at 25 °C , in the presence of an excess of PPh 3 (1.36 × 10 -1 M). If W(CO) 6 is formed in a geminate cage reaction, then, in a more viscous medium, cage escape should be hindered and the yield of W(CO) 6 should be increased.…”

“…Carbon monoxide gas (Linde/Union Carbide, C. P. grade) was used as provided. The complexes (Me 3 P)(OC) 4 OsW(CO) 5 , ( 1 ), Os(CO) 3 (PMe 3 )(PPh 3 ), and W(CO) 5 (PPh 3 ) ,, were prepared according to the literature and recrystallized from C 6 H 14 /CH 2 Cl 2 . The mononuclear complex Os(CO) 4 (PMe 3 ) was prepared according to the literature method except that a temperature of 360 ± 24 °C was employed …”