Variable temperature 13C NMR study of some L(CO) 3FeH(SiR 3) (L = CO, P(OPh) 3; R = Ph, Me, Cl) species. X-ray crystal structure of P(OPh) 3(CO) 3Fe(H)SiPh 3

Abstract

Intramolecular rearrangement of (CO) 4FeH(SiPh 3) ( I), (CO) 4FeH(SiMe 3) ( II), (CO) 4FeH(SiCl 3) ( III) and P(OPh) 3(CO) 3Fe(H)SiPh 3 ( IV), as studied by variable temperature 13C NMR spectroscopy, yielded activation enthalpies (kcal mol −1): 10.3±0.1, 10.4±0.4, 17.4±0.1 and 10.9±0.03, respectively, and activation entropies (cal deg −1 mol −1): −1.8 ± 0.5, −2.21 ± 0.1, 0.7 ± 0.5 and −2.2 ± 0.2, respectively. Crystal structure data for IV: C 39H 31FeO 6PSi, OC-6-23-tricarbonylhydrido(triphenylphosphite)(triphenylphosphine)iron(II), triclinic, P 1 , a = 11.509(2), b = 14.403(3), c = 11.153(4) Å, α = 108.04(2), β = 95.10(2), γ = 92.55(2)°, Z = 2, V = 1746(1) Å 3, final R factor 0.030. The structure is a highly distorted octahedron.