- Solid-State structure and solution reactivity of [(Ph3P)4Ru(H)2] and related Ru(II) complexes used in catalysis: A reinvestigation
-
X-ray analysis of [(Ph3P)4Ru(H)2] (1) prepared by a literature procedure [ Young, R.; Wilkinson, G. Inorg. Synth. 1990, 28, 337 ] shows that 1 is cocrystallized with PPh3, explaining the previously reported observations of free phosphine in solutions of 1. Lattice PPh3-free forms of 1 have also been obtained, structurally characterized, and found to generate small quantities of uncoordinated PPh3 and another species (A) in solution. Against previous beliefs, however, A is not [(Ph3P)3Ru(H)2] (2), but [(Ph3P)3Ru(H2)(H)2] (3) that forms in the reaction of 1 with adventitious water. This reaction apparently occurs via PPh3 loss from 1 to give 2, followed by H2O coordination, Ru(H)(OH2)/Ru(H2)(OH) rearrangement, H2 loss, and dimerization to give [(Ph3P)4Ru2(H)2(μ-OH)2] (4). The H2 thus produced is trapped with 2 to give 3. Complexes 3·0.5C6H6, 3·2THF, 4·2H2O, [(Ph3P)3Ru(N2)(H)2] (5), and [(Ph3P)2(H)Ru(μ-H)3Ru(PPh3)3]·0.5THF (6·0.5THF) have been structurally characterized for the first time. Also for the first time, a single-crystal X-ray diffraction study of the long-known [(Ph3P)4RuCl2] (7) has been performed to finally demonstrate that 7 is, in fact, [(Ph3P)3RuCl2]·PPh3, precisely as proposed by Hoffman and Caulton as early as 1975 [ Hoffman, P.R.; Caulton, K.G. J. Am. Chem. Soc. 1975, 97, 4221 ].
- Samouei, Hamidreza,Miloserdov, Fedor M.,Escudero-Adn, Eduardo C.,Grushin, Vladimir V.
-
-
Read Online
- Synthesis, NMR Study, and Reactivity of Isomeric Early-Late Heterobimetallic Dihydrides. X-ray Crystal Structure of (PPh3)HRu(μ-H)(μ-PMe2C5Me 4)2(μ-Cl)ZrCl
-
The new isomeric ruthenium/zirconium dihydrides of the formula (PPh3)HRuH(μ-PMe2Cp*)2ClZrCl (1, 2) (Cp* = C5Me4) have been characterized by elemental analysis and NMR (1H, 31P and 1H relaxation data). Complex 1, stabilized by Cl and H bridges, has been isolated from the room temperature reaction between RutyifeXPPhsh and (PMe2Cp*)2ZrCl2. The X-ray crystallographic study of 1 revealed a bimetallic complex. The six-coordinate Ru atom and the five-coordinate Zr atom are held together by two bifunctional phosphinocyclopentadienyl ligands and by H and Cl bridges. Crystal data for 1: monoclinic space group P21/c, a = 13.901(2) A?, b = 18.205(6) A?, c = 16.633(3) A?, β= 92.43(1)°, V = 4206 A?3, Z = 4, dcalc = 1.472 g cm-3, R(F) = 0.056, Rw(F) = 0.058. Complex 2 with two H bridges and terminal Cl ligands at Ru and Zr has been obtained by an irreversible isomerization of 1 in the presence of HNEt3BPh4. This transformation has been proposed to occur through slow protonation of one of the phosphorus ligands with the five-coordinate Ru center formed by undergoing rapid pseudorotation. Complexes 1 and 2 do not react with H2, N2, or 3,3-dimethyl-but-l-ene. Treatment of 1 with 1 equiv of NaHBEt2 in C6D6 gives a mixture of new trihydrides (PPh3)HRu(μ-Cl)(μ-H)(μ-PMe2Cp*) 2ZrH (3) and (PPh3)HRu(μ-H)2(μ-PMe2Cp*) 2ZrCl (4). Complex 3 transforms to 4 upon standing in solution for a period of several days. Under the same conditions, complex 2 leads smoothly to trihydride 4. Both trihydrides are new and have been characterized by 1H, 31P NMR, and 1H NMR relaxation data. Complexes 1 and 4 are fluxional in solution at room temperature, showing hydride exchange between the terminal and bridging positions. The variable-temperature 1H NMR spectra allowed determinations of the ΔG? values of 16.4 (313 K, THF-d8) and 13.5 kcal/ mol (295 K, toluene-d8) for the exchange in complexes 1 and 4, respectively. Possible exchange mechanisms have been discussed. Complex 2 is rigid on the NMR time scale.
- Bakhmutov, Vladimir I.,Visseaux, Marc,Baudry, Denise,Dormond, Alain,Richard, Philippe
-
-
Read Online
- Synthesis of ruthenium and iridium polyhydride complexes under conditions of phase transfer catalysis
-
The chlorohydrido complexes of ruthenium (Ph3P)3Ru(H)Cl and iridium (i-Pr3P)2Ir(H)Cl2 react smoothly with H2 (1 atm, 20 deg C) in a 50percent NaOH/benzene two-phase system in the presence of triethylbanzylammonium chloride as a phase transfer catalyst to form polyhydride complexes (Ph3P)3Ru(H2)(H)2 (1) and (i-Pr3P)2IrH5 (2), respectively, in quantitative yields.
- Grushin, V. V.,Vymenits, A. B.,Vol'pin, M. E.
-
-
Read Online
- Mild, Selective Ru-Catalyzed Deuteration Using D2O as a Deuterium Source
-
A method for the selective deuteration of polyfunctional organic molecules using catalytic amounts of [RuCl2(PPh3)3] and D2O as a deuterium source is presented. Through variation of additives like CuI, KOH, and various amounts of zinc powder, orthogonal chemoselectivities in the deuteration process are observed. Mechanistic investigation indicates the presence of different, defined Ru-complexes under the given specific conditions.
- Eisele, Pascal,Ullwer, Franziska,Scholz, Sven,Plietker, Bernd
-
supporting information
p. 16550 - 16554
(2019/12/11)
-
- New N,N-diisopropylcarbamato complexes of ruthenium(II) as catalytic precursors for olefin hydrogenation
-
During the synthesis of [Ru(O2CNiPr2) 2(PPh3)2] (1), the [RuCl2(PPh 3)3]/NHiPr2XCO2 system produces the intermediates [NH2iPr2][Ru2Cl 2(H-Cl)3(PPh3)4] (2) and [RuCl(O2C-NiPr2)(PPh3)3] (3) which have been isolated and fully characterised. Compound 2 contains the dinuclear anionic triply chloride-bridged rathenium(II) species. Compound 3 is mononuclear, the octahedral ruthenium centre being coordinated to the bidentate carbamato ligand. The reactions of compounds 1 and 3 with dihydrogen have been studied at room temperature and atmospheric pressure with respect to their catalytic hydrogenation of 1-octene. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Belli Dell'Amico, Daniela,Calderazzo, Fausto,Englert, Ulli,Labella, Luca,Marchetti, Fabio,Specos, Monica
-
-
- Bridging Fluorides and Hard/Soft Mismatch in d6 and d 8 Complexes: The Case of [TI(μ-F)3Ru(PPh 3)3]
-
[RuCl2(PPh3)3] reacts with thallium(I) fluoride to give either [Tl(μ-F)3Ru(PPh3)3] (1) or [Tl(μ3-F)(μ2-Cl)2RU 2(μ2-Cl)-(μ2-F)(PPh3) 4] (2) depending on the excess of TIF used. Both 1 and 2 were fully characterized, including X-ray structure determinations. Complex 1 reacts with dihydrogen to form the known ruthenium hydride complex [Ru-(H) 2(H2)(PPh3)3] upon hydrogenolysis of the Ru-F bond. The reaction of 1 with activated alkyl bromides (R-Br) gives the corresponding alkyl fluorides and the trinuclear complex [Tl(μ 3-F)(μ2-F)(μ2-X)Ru2(μ 2-Br)(μ2-F)(PPh3)4] (X = Br, F) (3), whose structure closely resembles that of 2. However, 1 is not active as catalyst for the nucleophilic fluorination of R-Br in the presence of thallium fluoride. The effect of the bridging coordination mode of fluoride on the Ru-F bond is discussed in terms of the HSAB principle, which suggests a more general model for predicting the stability of d6 and d8 complexes containing hard ligands (such as fluoro, oxo, and amido).
- Becker, Claus,Kieltsch, Iris,Broggini, Diego,Mezzetti, Antonio
-
p. 8417 - 8429
(2008/10/09)
-
- Reactivity of Ru(H2)(H)2(PPh3)3: Dimerization to form (PPh3)2(H)Ru(μ-H)3Ru(PPh3) 3 and decarbonylation of ethanol under mild conditions
-
Loss of H2 from RuH4(PPh3)3 (1) leads to formation of RuH2(PPh3)3; this intermediate has been shown to dimerize with loss of a phosphine to form (PPh3)2(H)Ru(μ-H)3Ru(PPh3) 3 (3). Formation of RuH2(PPh3)3 in the presence of ethanol leads to decarbonylation of the alcohol and formation of RuH2(PPh3)3(CO) (7), under the mild conditions of nonbasic solutions at 25°C. Reaction of 1 with methanol, 1-propanol, or benzyl alcohol at 60°C also results in decarbonylation and formation of 7. The mechanisms of formation of these complexes are discussed.
- Van Der Sluys, Lori Stepan,Kubas, Gregory J.,Caulton, Kenneth G.
-
p. 1033 - 1038
(2008/10/08)
-