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.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/b416917d | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Computational Study on the Proton Reduction Potential of Co, Rh, and Ir Molecular Electrocatalysts for the Hydrogen Evolution Reaction.
ACS Omega
December 2024
MolMod-CS-Instituto de Química, Universidade Federal Fluminense, Campos de Valonginho s/n, Centro, Niterói, Rio de Janeiro 24020-14, Brazil.
In this study, comprehensive density functional theory calculations were conducted to investigate the molecular mechanism of electrocatalytic proton reduction using group 9 transition metal bpaqH (2-(bis(pyridin-2-ylmethyl)amino)--(quinolin-8-yl)acetamide) complexes. The goal was to explore how variations in the structural and electronic properties among the three metal centers might impact the catalytic activity. All three metal complexes were observed to share a similar mechanism, primarily characterized by three key steps: heterolytic cleavage of H (HEP), reduction protonation (RPP), and ligand-centered protonation (LCP).
View Article and Find Full Text PDFCovalent Stabilization of the Iridium-Containing Oxyhydrides SrMnIrOH and SrMnIrOH.
Inorg Chem
November 2024
Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, United Kingdom.
Reaction between SrMnIrO and CaH or LiH yields the iridium-containing oxyhydride phases SrMnIrOH or SrMnIrOH, respectively. Analysis of Mn K-edge XANES data indicate the presence of Ir centers in these oxyhydride phases, whose low-spin d configuration is consistent with the "covalent stabilization" of the metastable oxyhydride phases, as seen previously in analogous ruthenium and rhodium containing materials. Neutron powder diffraction data indicate the hydride ions are located exclusively within the "equatorial" anion sites of SrMnIrOH.
View Article and Find Full Text PDFSynthesis of -Alkyl-1,3-dihydro-2,1-benzisoxazoles.
Org Lett
November 2024
Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States.
We describe a practical method for the synthesis of various substituted -alkyl-1,3-dihydro-2,1-benzisoxazoles and their 2,1-benzisoxazolone precursors starting from readily available methyl 2-nitrobenzoates. The method entails partial nitro reduction with hydrazine and rhodium on carbon to give the hydroxylamines, followed by base-mediated cyclization to give the corresponding benzisoxazol-3(1)-ones. Subsequent alkylation is conducted under basic conditions and is followed by reduction to the target 1,3-dihydrobenzisoxazoles, achieved with lithium aluminum hydride in the presence of trimethylsilyl chloride.
View Article and Find Full Text PDFFlash Communication: Rhodium Complexes of Acetamide-Derived PAlP Pincer.
Organometallics
October 2024
Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
The new alane/bis(phosphine) PAlP pincer-type ligands and have been prepared by protolysis reactions of -(diisopropylphoshino)acetamide with MeAl or EtAl in a 2:1 ratio. Upon reaction with a "RhCl" source and pyridine, gave rise to a (PAlP)RhMe(py) compound (), while led to the analogous hydride complex (PAlP)RhH(py) (), with a migration of the chloride from Rh to Al. and possess the shortest Rh-Al bonds to date.
View Article and Find Full Text PDFProtonation of Dppbz- and Binap-Ligated Rhodathiaboranes Yielding Hydron, Hydride, and Hydrogen Exchange.
Inorg Chem
October 2024
Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain.
The reaction of the 11-vertex rhodathiaborane [8,8,8-(H)(PPh)-3-(NCH)--7,8-RhSBH] () with 1,2-bis(diphenylphosphine)benzene (dppbz) and ()-(-)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (binap) affords [1,1-(η-dppbz)-3-(NCH)--1,2-RhSBH] () and [1,1-(η-binap)-3-(NCH)--1,2-RhSBH] (). These 11-vertex -rhodathiaborane chelates result from PPh ligand substitution at the rhodium center and a -to- structural cluster transformation driven by H loss. Treating compounds and with triflic acid (TfOH) leads to the formation of cationic clusters and .
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!