870854-26-5Relevant articles and documents
Ruthenated acetonitrile: Unusual bronsted acidity of a polar Aprotic solvent
Derrah, Eric J.,Giesbrecht, Karina E.,McDonald, Robert,Rosenberg, Lisa
, p. 5025 - 5032 (2009/03/11)
Addition of acetonitrile to the complex [Ru(η5-indenyl) (PR2)(PPh3)] (1) gives the unusual metalation product [Ru(η5-indenyl)(CH2CN)(HPR2)(PPh 3)] (2), which has been structurally characterized. This reaction clearly demonstrates high Bronsted basicity at the terminal phosphide ligand in 1. 31P{1H} NMR studies show that less acidic N-donor solvents simply disrupt the Ru-P π-bond in 1 to give adducts [Ru(η5-indenyl)(L)(HPR2)(PPh3)] (L = benzonitrile (6) or pyridine (7)), which are in equilibrium with 1 and free L. The analogous acetonitrile adduct (4) was observed by NMR at 240 K during the formation of 2, but is quickly replaced by 2 at higher temperatures. NMR studies of an alternate route to the metalated complex 2, starting from the cationic N-bound acetonitrile adduct [Ru(η5-indenyl)(NCCH 3-(HPCy2)(PPh3)][PF6] (3a), along with the demonstrated lability of the benzonitrile and pyridine adducts, suggest that the metalation of acetonitrile by 1 proceeds via an intermolecular C-H addition across the Ru=P double bond, rather than the intramolecular C-H activation of N-bound acetonitrile. This is confirmed by the observation, by 31P[1H} NMR, of multiple product isotopomers in the reaction of 1 with a 1:1 mixture of d3- and d0- acetonitrile. O-Donor solvents also deprotonated by 1 include water, alcohols, and acetone, which give the complexes [Ru(η5-indenyi)(X) (HPCy2)(PPh3)], where X = OR (8), CH2(=O) CH3 (10).
A highly reactive ruthenium phosphide complex exhibiting Ru-P π-bonding
Derrah, Eric J.,Pantazis, Dimitrios A.,McDonald, Robert,Rosenberg, Lisa
, p. 1473 - 1482 (2008/10/09)
Multiple bonding in the terminal phosphido complex [Ru(PCy 2)(η5-indenyl)(PPh3)J (2a) is clearly demonstrated by solution, solid-state, and computational studies. Reactions of this dark blue, half-sandwich complex with CO, MeI, HNEt3Cl, HCl, NH4PF6, H2, and Et3SiH demonstrate an unusual range of behavior resulting from combined coordinative unsaturation at Ru, high nucleophilicity/basicity of the phosphido P, and π-character of the Ru-P interaction. The terminal, π-bound phosphido structure is general for a range of PR2 species (R = Pri (2b), Ph (2c), Tolp (2d)). The very reactive diarylphosphido analogues 2c,d have been observed spectroscopically at low temperatures and can be trapped quantitatively as their CO adducts, [Ru(PAr2)(η5- indenyl)(CO)(PPh3)] (3c,d), in which the Ru-P bond order is reduced to 1. Complex 2a and its analogue [Ru(PPri2) (η5-indenyl)(PPh3)] (2b) are consistently isolated with ～15% of their structural isomers, the ruthenium hydrido phosphaalkenes 9a,b, resulting from an apparent 1,2-H shift.
Electronic control of conformation in mixed-phosphine complexes of the ruthenium η5-indenyl fragment
Derrah, Eric J.,Marlinga, Jazmin C.,Mitra, Debbie,Friesen, Dawn M.,Hall, Shaun A.,McDonald, Robert,Rosenberg, Lisa
, p. 5817 - 5827 (2008/10/09)
The solid-state conformations of a series of new, mixed secondary and tertiary phosphine complexes of the general formula [Ru(η5- indenyl)Cl(PPh3)(HPR2)] have been shown to persist in solution, largely because of the electronic requirements of the ancillary η5-indenyl ligand in these complexes. The crystallographically observed conformations, with the indenyl benzo ring lying anti to the secondary phosphine across the Ru-η5-indenyl bond, were diagnosed in solution from chemical shift differences for PPh3 signals in the low-temperature-limiting 1H and 13C NMR spectra. These conformations were tuned by varying the relative trans influences of the different piano-stool legs, in particular through preparation of the analogous hydrido complexes [Ru(η5-indenyl)H(PPh3)(HPR 2)], which resulted in structures with the indenyl benzo ring anti to the hydride ligand. These studies provide evidence for the reasonably strong trans influence of coordinated secondary phosphines relative to PPh3. Implications for the ancillary ligand behavior of secondary phosphines are discussed.
