Reactions of carbonylchlorohydridobis(triisopropylphosphine)ruthenium with molecular hydrogen in solution. New molecular hydrogen complexes of ruthenium: RuH(H2)Cl(CO)[P(iso-Pr)3]2 and Ru(H)2(H2)(CO)[P(iso-Pr)3]2 (original) (raw)
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Inorganic Chemistry, 1998
The reaction of RuH 2 (H 2) 2 (PCy 3) 2 (1) with L-X in pentane at room temperature yields new hydrido derivatives of ruthenium accommodating a stretched H-H bond, namely RuH(H 2)(L-X)(PCy 3) 2 (L-X = C 5 H 4 NO , 2; L-X = C 5 H 4 N-NH, 3). NMR studies show that hydrogen bond donors (substituted phenols, hexafluoro-2-propanol, etc.) interact with the hydrides in the case of 2, whereas for 3 an equilibrium with the cation [RuH(H 2)(py-NH 2)(PCy 3) 2 ] + is attained. The latter species has been isolated in the form of the [B(C 6 F 5) 4 ] salt, 4, independently prepared by addition of (PhNMe 2 H)[B(C 6 F 5) 4 ] to 3. These phenomena explain the difference of reactivity with olefins between 2 and 3 in nonpolar media or in the presence of alcohols.
2014
In this paper the synthesis and characterisation of ruthenium dihydrogen complexes bearing rigid aliphatic PNP pincer-type ligands are described. As one result hydride complexes were synthesised in good to high yields by a one-pot direct hydrogenation reaction. As another finding the dihydrogen complex, stabilised with a N-Me group in the ligand frame, can be converted with dimethylamine borane into a rare σ-boron complex [RuH 2 (BH 3 )(Me-PNP)] with rapid B-N decoupling. Additionally, we present the first mass spectrometric analysis of the synthesised σ-complexes via liquid injection field desorption/ ionisation technique (LIFDI-MS). † Electronic supplementary information (ESI) available. CCDC 952413. For ESI and crystallographic data in CIF or other electronic format see
Ortho-Metalated Ruthenium Hydrido Dihydrogen Complexes: Dynamics, Exchange Couplings, and Reactivity
Organometallics, 2004
The ortho-metalated X ligand is coordinated to ruthenium via the nitrogen of one ring and the ortho carbon of a second ring as a result of C-H activation. 2 and 3 were characterized by X-ray diffraction. They are the first examples of complexes displaying exchange couplings between the hydride and the dihydrogen ligands. NMR studies and DFT calculations are used to understand this phenomenon. The series of ortho-metalated model complexes RuH-(H 2 )(X)(PH 3 ) 2 was investigated by DFT at the B3PW91 level. The coherent (quantummechanical) as well as the incoherent (classical) exchange rates have been determined by line shape analysis, and the activation energies hardly depend on the nature of the X ligand: E a (coherent) ) ca. 10 kJ mol -1 , E a (incoherent) ) ca. 40 kJ mol -1 (ca. 50 kJ mol -1 by DFT). The corresponding transition states (2q TSQEC -4q TSQEC ) for the classical exchange process have been located by DFT at the B3PW91 level. The dihydrogen ligand is now trans to N and perpendicular to the plane of the chelating ligand. These states connect to the isomer with the dihydrogen trans to C through coupled rotation of H 2 and proton transfer from H 2 to H. The dihydrogen ligand can be substituted easily, and the corresponding complexes RuH(L)(ph-py)(P i Pr 3 ) 2 with L ) N 2 (5), O 2 (6), CO (7), C 2 H 4 (8) have been isolated and fully characterized by NMR and by crystal structure analyses in the case of 6 and 8. The model systems RuH(L)(ph-py)(PH 3 ) 2 (5q-8q) have been optimized at the DFT level (B3PW91). In the case of 8, we could not detect any ethylene insertion in either the Ru-H or the Ru-C bond. Theoretical calculations explain the differences we observed with the Murai type catalysts, which are highly reactive to ethylene insertion.
Inorganic Chemistry, 1997
Complexes of the general formula [MXH 2 (dppp) 2 ] n+ (M ) Ru, Os; X ) H, Cl, CO; dppp ) 1,3-bis-(diphenylphosphino)propane) have been prepared and characterized, and the effect of the donor/acceptor properties of X on their structure and acidity has been studied. The five-coordinate complexes [MCl(dppp) 2 ] + (M ) Ru (1a), Os (1b)) react with H 2 gas in CH 2 Cl 2 to give the complexes [MCl(η 2 -H 2 )(dppp) 2 ] + (M ) Ru (2a), Os (2b)) containing elongated dihydrogen ligands. The molecular structure of 2b has been determined by X-ray crystallography (monoclinic, space group P2 1 /n with a ) 13.314 Å, b ) 18.63(2) Å, c ) 23.20(2) Å, ) 94.58(6)°, and Z ) 4). Chlorohydride [OsH(Cl)(dppp) 2 ] (3b) reacts with H 2 gas in the presence of Na[BPh 4 ] forming [OsH 3 (dppp) 2 ] + (4b). Protonation of [OsH 2 (dppp) 2 ] (5b) with HBF 4 ‚Et 2 O also gives 4b. A combination of X-ray crystallography (monoclinic, space group P2 1 /n with a ) 13.392(3) Å, b ) 25.306(7) Å, c ) 21.247(7) Å, ) 91.15(2)°, and Z ) 4) and 1 H and 31 P NMR studies indicate that 4b is a classical trihydride. Hydridocarbonyls [MH(CO)(dppp) 2 ] + (M ) Ru (6a), Os (6b)) are protonated by F 3 CSO 3 H in CD 2 Cl 2 to yield [M(CO)(η 2 -H 2 )(dppp) 2 ] 2+ (M ) Ru (7a), Os ), which were characterized in solution. 7a is stable only at low temperature. Compound 7b is a highly acidic dihydrogen complex with an estimated pK a of -6.
Inorganic Chemistry, 2004
Chloro complexes [RuCl(N-N)P 3 ]BPh 4 (1−3) [N-N ) 2,2′-bipyridine, bpy; 1,10-phenanthroline, phen; 5,5′-dimethyl-2,2′-bipyridine, 5,5′-Me 2 bpy; P ) P(OEt) 3 , PPh(OEt) 2 and PPh 2 OEt] were prepared by allowing the [RuCl 4 (N-N)]‚ H 2 O compounds to react with an excess of phosphite in ethanol. The bis(bipyridine) [RuCl(bpy) 2 {P(OEt) 3 }]BPh 4 (7) complex was also prepared by reacting RuCl 2 (bpy) 2 ‚2H 2 O with phosphite and ethanol. Treatment of the chloro complexes 1−3 and 7 with NaBH 4 yielded the hydride [RuH(N-N)P 3 ]BPh 4 (4−6) and [RuH(bpy) 2 P]BPh 4 (8) derivatives, which were characterized spectroscopically and by the X-ray crystal structure determination of [RuH(bpy){P(OEt) 3 } 3 ]-BPh 4 (4a). Protonation reaction of the new hydrides with Brønsted acid was studied and led to dicationic [Ru(η 2 -H 2 )(N-N)P 3 ] 2+ (9, 10) and [Ru(η 2 -H 2 )(bpy) 2 P] 2+ (11) dihydrogen derivatives. The presence of the η 2 -H 2 ligand was indicated by a short T 1min value and by the measurements of the J HD in the [Ru](η 2 -HD) isotopomers. From T 1min and J HD values the H−H distances of the dihydrogen complexes were also calculated. A series of ruthenium complexes, [RuL(N-N)P 3 ](BPh 4 ) 2 and [RuL(bpy) 2 P](BPh 4 ) 2 (P ) P(OEt) 3 ; L ) H 2 O, CO, 4-CH 3 C 6 H 4 NC, CH 3 CN, 4-CH 3 C 6 H 4 CN, PPh(OEt) 2 ], was prepared by substituting the labile η 2 -H 2 ligand in the 9, 10, 11 derivatives. The reactions of the new hydrides 4−6 and 8 with both mono-and bis(aryldiazonium) cations were studied and led to aryldiazene [Ru(C 6 H 5 NdNH)(N-N)P 3 ](BPh 4 ) 2 (19, 21), [{Ru(N-N)P 3 } 2 (µ-4,4′-NHdNC 6 H 4 −C 6 H 4 NdNH)](BPh 4 ) 4 (20), and [Ru(C 6 H 5 NdNH)(bpy) 2 P](BPh 4 ) 2 (22) derivatives. Also the heteroallenes CO 2 and CS 2 reacted with [RuH-(bpy) 2 P]BPh 4 , yielding the formato [Ru{η 1 -OC(H)dO}(bpy) 2 P]BPh 4 and dithioformato [Ru{η 1 -SC(H)dS}(bpy) 2 P]-BPh 4 derivatives.