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Updated: Feb 24, 2026
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
N-Heterocyclic Carbene-Phosphinidene and Carbene-Phosphinidenide Transition Metal Complexes
Marius Peters1, Adinarayana Doddi1, Thomas Bannenberg1
1Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig , Hagenring 30, 38106 Braunschweig, Germany.
Abstract:
Half-sandwich complexes of the N-heterocyclic carbene-phosphinidene adduct [(IPr)PH] (1, IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were prepared by its reaction with dimeric complexes of the type [LMCl2]2, which afforded the three-legged piano-stool complexes [LMCl2{HP(IPr)}] (9a/9b: M = Ru/Os, L = η6-p-cymene; 10a/10b: M = Rh/Ir, L = η5-C5Me5). Their conversion into the corresponding carbene-phosphinidenide complexes [LMCl{P(IPr)}] (11a/11b: M = Ru/Os; 12a/12b: M = Rh/Ir) with a two-legged piano stool geometry was studied by NMR spectroscopy in the presence of the strong base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Alternatively, the complexes 11 and 12 were isolated in high yields from the reactions of the carbene-phosphinidene adduct [(IPr)PTMS] (2) with [LMCl2]2, whereby formation of the metal-phosphorus bonds was accompanied by elimination of trimethylsilyl chloride (Me3SiCl). Theoretical calculations reveal a strong polarization of the phosphorus ligands upon metal complexation, which can be ascribed to the ability of the imidazole moiety to effectively stabilize a positive charge. Dehydrohalogenation of complexes 9/10 to 11/12 affords a significant increase of the metal-phosphorus bond order, with the carbene-phosphinidenide ligand acting as a strong 2σ,2π-electron donor.
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