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Updated: Nov 26, 2025
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
E-Selective Synthesis and Coordination Chemistry of Pyridine-Phosphaalkenes: Five Ligands Produce Four Distinct Types
Mika L Nakashige1, Jarin I P Loristo1, Lesley S Wong1
1Department of Chemistry, University of Hawai'i at Mānoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States.
Abstract:
Pyridine-phosphaalkene (PN) ligands 2a-e were prepared in an E-selective fashion using phospha-Wittig methodology. Treatment of these five ligands, varying only in their 6-substituent with RuCl2(PPh3)3, produced four distinct types of coordination complexes: pyridine-phosphaalkene-derived 3b,d, cyclized 4e, and six-coordinate 5a and 6c. Prolonged heating of 3b,d in THF resulted in C-H activation of the Mes* group and cyclization to give 4b,d featuring a bidentate pyridine-phospholane ligand bound to the metal center. Complex 5a, also possessing a newly formed phospholane ring, contained a different spatial arrangement of donors to Ru(II) with an agostic Ru-H-C interaction serving as the sixth donor to the transition metal center. Ligands 2b,d,e and Ru(II) complexes 3b, 4b,e and 5a were all characterized by X-ray crystallography. Six-coordinate 6c featured a structure similar to 4b,d,e, but with the CF3 substituent acting as a weakly bound sixth ligand to the Ru(II) center, as observed by 31P{1H} and19F NMR spectroscopy. The calculated structure of 6c established that the closest Ru- - -F contact was at 2.978 Å.
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