Stereoselective Synthesis of a Phenylphosphido-Bridged Dimetallic Complex: Crystal and Molecular Structure of [(R̲*,R̲*),(R̲*)]-(±)-[η5-C5H5){1,2-C6H4(PMePh)2}FePHPh{Cr(CO)5}] · 2 H2O · 0.5 CH2Cl2 · 0.5 C4H8O

Abstract

Deprotonation of (R̲*,R̲*)-(±))-[η5-C5H5){1,2-C6H4(PMePh)2}Fe(PH2Ph)]PF6 with n-BuLi in tetrahydrofuran at 20°C, followed by treatment of the intermediate phenylphosphido-iron complex with [Cr(CO)5(NMe3)] produces a separable 3: 2 mixture of the diastereomers [(R̲*,R̲*),(R̲*)]- and [(R̲*,R̲*),(S̲*)]-(±)-[(η5-C5H5){1,2-C6H4(PMePh)2}Fe-PH(Ph) → Cr(CO)5]. The major component of the mixture crystallizes from dichloromethane-tetrahydrofuran in the atmosphere as the mixed solvate (R̲*,R̲*)-(±))-[η5-C5H5){1,2-C6H4(PMePh)2}Fe(PH2Ph)]Fe-PH(Ph) → Cr(CO)5]· 2 H2O-0.5 CH2Cl2 · 0.5 C4H8O in the triclinic space group P1̅ with two formula units in the unit cell; the lattice constants are a = 10.933(2) Å, b = 13.161(4) Å, c = 15.249(3) Å, α = 76.83(1)°, β = 75.62(3)°, and γ = 79.31(1)°. In the structure, the pyramidal phenylphosphido group bridges the dissimilar metals via relatively long metal-phosphorus bonds, viz., Fe-P = 2.285(5) Å, Cr-P = 2.511(4) Å.