Protonation of [Mo2Cp2(mu-H)(mu-PHR*)(CO)4] (Cp = eta5-C5H5, R* = 2,4,6-C6H2tBu3) with HBF4.OEt2 gives the hydridophosphinidene complex [Mo2Cp2(mu-H)(mu-PR*)(CO)4]BF4, which is easily deprotonated with H2O to give the known phosphinidene complex [Mo2Cp2(mu-PR*)(CO)4] in 95% yield. Reaction of the latter with I2 gives the unsaturated phosphinidene complex [Mo2Cp2I2(mu-PR*)(CO)2], which exhibits an intermetallic distance of 2.960(2) A. Irradiation of solutions of [Mo2Cp2(mu-PR*)(CO)4] with UV light gives a mixture of the triply bonded [Mo2Cp2(mu-PR*)(mu-CO)2] and the hydridophosphido derivative [Mo2Cp2(mu-H){mu-P(CH2CMe2)C6H2tBu2}(CO)4] as major species. The latter complex results from an intramolecular C-H bond cleavage from a tBu group and has been characterized by spectroscopy and an X-ray study. Irradiation in the presence of HCC(p-tol) results in the insertion of the alkyne into the Mo-P bond to give [Mo2Cp2{mu-eta1:eta2,kappa-C(p-tol)CHPR*}(CO)4] structurally characterized through an X-ray study.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja021072o | DOI Listing |
Chem Commun (Camb)
November 2024
TUM School of Natural Sciences, Department of Chemistry, Catalysis Research Center and Wacker-Institute of Silicon Chemsitry, Technische Universität München (TUM), Lichtenbergstrasse 4, 85748 Garching bei München, Germany.
Herein, we report the reactivity of N-heterocyclic carbene stabilized silylene-phosphinidene IDippPSi(TMS)SiTol (IDipp = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) with ammonia, which results in an intermolecular 1,5-hydroamination and dearomatization of the NHC wingtip. DFT calculations reveal an unprecedented mechanism involving ammonia coordination to the silicon center, Meisenheimer-type complex formation, and a proton abstraction by the dearomatized aryl moiety.
View Article and Find Full Text PDFChem Sci
September 2024
Fakultät für Chemie, Technische Universität München Lichtenberg Strasse 4 85747 Garching Germany
Macrocyclic bis-diphosphenes, formally heavier derivatives of macrocyclic azobenzenes, are accessed for the first time. These are synthesised in a reproducible fashion, through the nickel-mediated homocoupling of xanthene-derived NHC-stabilised bis-phosphinidene units. This gives direct access to target macrocyclic bis-diphosphenes 2, featuring -cyclic coordinated Ni fragments.
View Article and Find Full Text PDFJ Am Chem Soc
July 2024
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 200433 Shanghai, China.
Carbonyl nitrenes are versatile intermediates that have been extensively characterized; however, their phosphorus analogues remain largely unknown. Herein, we report the observation of a rare example of carbonyl phosphinidene NHC(O)P, which was generated through the photolytic (193 nm) dehydrogenation of phosphinecarboxamide (NHC(O)PH) in a solid N-matrix at 12 K. The characterization of NHC(O)P in the triplet ground state with matrix-isolation IR and ultraviolet-visible (UV-vis) spectroscopy is supported by comprehensive isotope labeling experiments (D and N) and quantum chemical calculations.
View Article and Find Full Text PDFChem Commun (Camb)
July 2024
University of Innsbruck, Center for Chemistry and Biomedicine, Department of General, Inorganic and Theoretical Chemistry, Innrain 80-82, 6020 Innsbruck, Austria.
Synthesis of a bulky anilidophosphine ligand (short PN) and its lanthanum complexes 1 and 3 is reported. When exposed to KPHMes, both complexes form the first example of a bis-phosphanido-phosphinidene complex 2. This complex undergoes Phospha-Wittig type reactions and its reactivity towards strong bases is further investigated.
View Article and Find Full Text PDFInorg Chem
June 2024
Department of Chemistry, University of California, Berkeley, California 94720, United States.
We expand upon the synthetic utility of anionic rhenium complex Na[(BDI)ReCp] (, BDI = -bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate) to generate several rhenium-phosphorus complexes. Complex reacts in a metathetical manner with chlorophosphines PhPCl, NHP-Cl, and OHP-Cl to generate XL-type phosphido complexes , , and , respectively (NHP-Cl = 2-chloro-1,3-dimethyl-1,3,2-diazaphospholidine; OHP-Cl = 2-chloro-1,3,2-dioxaphospholane). Crystallographic and computational investigations of phosphido triad , , and reveal that increasing the electronegativity of the phosphorus substituent (C < < O) results in a shortening and strengthening of the rhenium-phosphorus bond.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!