910783-90-3Relevant academic research and scientific papers
Influence of the electronics of the phosphine ligands on the H-H bond elongation in dihydrogen complexes
Dutta, Saikat,Jagirdar, Balaji R.,Nethaji, Munirathinam
, p. 548 - 557 (2008/10/09)
Five new monocationic dihydrogen complexes of ruthenium of the type trans-[RuCl(η2-H2)(PP)2][BF4] (PP = bis-1,2(diarylphosphino)ethane, aryl = p-fluorobenzyl, 1a, benzyl, 2a, m-methylbenzyl, 3a, p-methylbenzyl, 4a, p-isopropylbenzyl, 5a) have been prepared by protonating the precursor hydride complexes trans-[RuCl(H)(PP) 2] using HBF4·OEt2. The dihydrogen complexes are quite stable and have been isolated in the solid state. The intact nature of the H-H bond in these derivatives has been established from the short spin-lattice relaxation times (T1, ms) and observation of substantial H, D couplings in the HD isotopomers. The H-H bond distances (dHH, A) increase systematically from 0.97 to 1.03 A as the electron-donor ability of the substituent on the diphosphine ligand increases from the p-fluorobenzyl to the p-isopropylbenzyl moiety. The dHH in trans-[Ru(η2-H2)(Cl)((C6H 5-CH2)2PCH2CH2P(CH 2C6H5)2)2][BF 4], 2a, was found to be 1.08(5) A by X-ray crystallography. In addition, two new 16-electron dicationic dihydrogen complexes of the type [Ru(η2-H2)(PP)2][OTf]2 (PP = (ArCH2)2PCH2CH2P(CH 2-Ar)2, Ar = m-CH3C6H4-, 6a, p-CH3C6H4-, 7a) have also been prepared and characterized. These derivatives were found to possess elongated dihydrogen ligands.
16-Electron elongated dihydrogen complex stabilized by agostic interaction
Dutta, Saikat,Jagirdar, Balaji R.
, p. 7047 - 7049 (2008/10/09)
A 16-electron dicationic dihydrogen complex [Ru(η2- H...H)(PP)2][OTf]2 [4; PP = (C6H 5CH2)2PCH2CH2P(CH 2C6H5)2] has been prepared and characterized by protonating the precursor hydride complex [Ru(H)(PP) 2)][OTf] (2) using HOTf. The hydride and dihydrogen complexes are stabilized via agostic interaction of the ortho C-H fragment of the phenyl ring on the benzyl group. The intact nature of the H-H bond in this derivative was established from the short spin-lattice relaxation time and the observation of a substantial J(H,D) of 22.0 Hz for the HD isotopomer. The H-H bond distance calculated from J(H,D) is 1.05 A, which falls under the category of elongated dihydrogen ligands.
