| Abstract
| - The reaction of K+[HCr(CO)5]- with phosphanes PR3 (R = Et, Ph, NMe2) in THF at 65 °C affords the disubstituted complexes Cr(CO)4(PR3)2 isolated in 57−70%. These reactions proceed via the monosubstituted hydridocarbonylchromates K+[HCr(CO)4PR3]-, fully characterized by 1H, 31P, and 13C NMR for R = Et and Ph. The X-ray crystal structures of Cr(CO)4(PR3)2 derivatives have been determined for R = Et and NMe2.
- The reaction of K+[HCr(CO)5]- with phosphanes PR3 (R = Et, Ph, NMe2) in THF at 65 °Caffords the disubstituted complexes trans-Cr(CO)4(PR3)2 isolated in 57−70% yield. The X-raycrystal structures of trans-Cr(CO)4(PR3)2 derivatives have been determined for R = Et andNMe2. These reactions proceed first by exchange of one carbon monoxide ligand, generatingthe monosubstituted hydridotetracarbonylchromates K+[HCr(CO)4PR3]-, observed andcharacterized by NMR spectroscopy for R = Et and Ph. The second step involves substitution of the hydride ligand of K+[HCr(CO)4PR3]- to give the disubstituted derivatives trans-Cr(CO)4(PR3)2. These ligand exchange processes are discussed and compared with the reactionof phosphanes with the dinuclear bridged K+(μ-H)[Cr(CO)5]2-.
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