Crous Renier, Datt Michael, Foster Douglas, Bennie Linette, Steenkamp Casper, Huyser Johan, Kirsten Leo, Steyl Gideon, Roodt Andreas
Sasol Technology R & D, P.O. Box 1, Sasolburg 1947, South Africa.
Dalton Trans. 2005 Mar 21(6):1108-16. doi: 10.1039/b416917d. Epub 2005 Feb 17.
A study has been carried out on rhodium catalyst preforming when modified with the bulky tris(2,4-di-tert-butylphenyl) phosphite, P(Obtbp)(3). X-Ray crystal structure determinations of a tropolone-type precursor complex [Rh(TropBr(3))(CO){P(Obtbp)(3)}].P(Obtbp)(3).CH(3)COCH(3)(TropBr(3)= 3,5,7-tribromotropolonate) and the free P(Obtbp)(3) ligand are reported. Systematic in situ IR and NMR studies of the particular rhodium phosphite modified catalyst and its precursors have led to the identification of two distinct rhodium hydride species. A {(1)H,(31)P} HMBC NMR experiment afforded clarity on the (31)P NMR spectra observed under hydroformylation conditions. The species were identified as [HRh(CO)(3){P(Obtbp)(3)}] and [HRh(CO)(2){P(Obtbp)(3)}(2)]. Attention was also given to the rate of catalyst formation when starting from different rhodium precursors.
已对用大位阻亚磷酸三（2,4 - 二叔丁基苯基）酯P(Obtbp)(3)改性的铑催化剂预成型进行了一项研究。报道了一种托酚酮型前体配合物[Rh(TropBr(3))(CO){P(Obtbp)(3)}].P(Obtbp)(3).CH(3)COCH(3)（TropBr(3)= 3,5,7 - 三溴托酚酮酸根）和游离P(Obtbp)(3)配体的X射线晶体结构测定。对特定的亚磷酸铑改性催化剂及其前体进行的系统原位红外和核磁共振研究已鉴定出两种不同的铑氢化物物种。{(1)H,(31)P} HMBC核磁共振实验使在氢甲酰化条件下观察到的(31)P核磁共振谱清晰明了。这些物种被鉴定为[HRh(CO)(3){P(Obtbp)(3)}]和[HRh(CO)(2){P(Obtbp)(3)}(2)]。还关注了从不同铑前体开始时催化剂的形成速率。
