Download or read book Synthesis and Reactivity of Some Acidic Ruthenium Dihydrogen written by TINA PUI WAH. FONG and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Some Acidic Ruthenium Dihydrogen and Hydride Complexes written by Tina Pui Wah Fong and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reaction of Cp*Ru(dfepe)Cl (1) in dry CH2Cl 2 at -78°C with H2 (g) and AgOTf produced a mixture of Cp*Ru(dfepe)H (2) and [Cp*Ru(dfepe)(H)2] + as shown by 1H NMR spectroscopy. The addition of excess HOW to the mixture of monohydride and dihydride under H2 (g) gave only the dihydride. X-ray diffraction studies of the dfepe complexes 1 and 2 revealed close contacts between the fluorine atoms of the dfepe ligand and the hydrogen atoms on the methyl groups of the Cp* ligand. Cyclic voltammetry studies, were carried out on 1 and 2 and the redox potentials were found to be quite positive. The EL value of 1/2 dfepe was found to be 0.89 V (NIHE), similar to CO. From the X-ray diffraction study, the complex Cp*Ru(tmbp)H (6) has a distorted three-legged piano stool structure and the tmbp ligand is relatively planar. The 'E'L value of 1/2 tmbp was found to be 0.52 V (NHE), similar to dppm. The hydrido cyano ruthenium (II) complexes 'trans'-[RuH(CN)(L) 2] (L = dppe or depe) were protonated with one equivalent of acid to produce 'trans'-[RuH(CNH)(dppe)2](OTf) (12 ) and 'trans'-[Ru([eta]2-H2)(CN)(depe) 2](BF4) (21). The addition of a second equivalent of acid to complex 12 produced the dihydrogen Complex ' trans'-RU([eta]2-H2)(CN)(dPPe)2](TfO···HOTf) (15). The highly acidic dicationic dihydrogen complex, ' trans'-[Ru([eta]2-H2)CNH(dppe)2](TfO···HOTf) 2 (13), was observed when two equivalents of acid was added to complex 15. Complex 13 was deprotonated by El 2O, reforming complex 15. Complex 15 was unstable and readily lost H2 under Ar forming 'trans'-[Ru(OTf)(CNH)(dppe) 2](OTf) (14). When complex 14 was placed under H2 gas, complex 15 reformed. This is a rare example of the formation of an acidic dihydrogen complex from H2 gas. Both dihydrogen complexes 13 and 15 have H-H distances of 0.88 Å which were determined from 1'J'(HD) values (32.4 Hz and 32.0 Hz, respectively). Another example of the formation of an acidic dihydrogen complex from H2 gas is the formation of the termally unstable complex ' trans'-[Ru([eta]2-H2)(CN)(dppe)2](OTf) (18) from 'trans'-[Ru(OTf)(CN)(dppe)2] (17). The dihydrogen complex rearranges to the thermodynamically stable complex 12 at room temperature. The Inelastic Neutron Scattering (INS) study of 'trans'-[Ru([eta] 2-H2)H(dppe)2][BPh4] revealed weak [pi]-backbonding from the Ru centre to the dihydrogen ligand. The room temperature solution 2H NMR spectrum revealed that 'trans'-[Ru([eta] 2-D2)Cl(dppe)2]PF6 (22) readily undergoes H/D exchange with the dppe ligands. From the variable temperature solid state 2H NMR spectra of 22, the coherent tunneling frequency of the deuterons of the dideuterium ligand was observed to be 60.8 kHz. (Abstract shortened by UMI.).

Download or read book Synthesis and Reactivity of a Novel Benzene Ruthenium II Lewis Acid written by Steven William Singer and published by . This book was released on 1996 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ruthenium in Organic Synthesis written by Shun-Ichi Murahashi and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this comprehensive book, one of the leading experts, Shun-Ichi Murahashi, presents all the important facets of modern synthetic chemistry using Ruthenium, ranging from hydrogenation to metathesis. In 14 contributions, written by an international authorship, readers will find all the information they need about this fascinating and extraordinary chemistry. The result is a high quality information source and a indispensable reading for everyone working in organometallic chemistry. From the contents: Introduction (S.-I. Murahashi) Hydrogenation and Transfer Hydrogenation (M. Kitamura and R. Noyori) Oxidations (S.-I. Murahashi and N. Komiya) Carbon-Carbon Bond Formations via Ruthenacycle Intermediates (K. Itoh) Carbon-Carbon Bond Formation via pi-Allylruthenium Intermediates (T. Mitsudo) Olefin Metathesis (R. H. Grubbs) Cyclopropanation (H. Nishiyama) Nucleophilic Addition to Alkynes and Reactions via Vinylidene Intermediates (P. Dixneuf) Reactions via C-H Activation (N. Chatani) Lewis Acid Reactions (E. P. Kundig) Reactions with CO and CO2 (T. Mitsudo) Isomerization of Organic Substrates Catalyzed by Ruthenium Complexes (H. Suzuki) Radical Reactions (H. Nagashima) Bond Cleavage Reactions (S. Komiya)

Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this jOint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 40 (thesis year 1995) a total of 10,746 thesis titles from 19 Canadian and 144 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 40 reports theses submitted in 1995, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

Download or read book Synthesis and Investigation of Some Cationic and Neutral Ruthenium Dihydrogen and Hydride Complexes written by Sandra E. Trentowsky and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reversible binding of dihydrogen gas on [Ru([eta]2-H 2)H(dppe)2]+ [X]-, where X- = BPh4, B(Arf)4, BF4, PF6 was investigated using 31P and 13C solid state NMR spectroscopy. X-ray crystal structure analysis of the new species [RuH(dppe)2]+ [BPh4] -, [Ru([eta]2-H2)H(dppe)2] + [B(Arf)4]- and [RuCl(dppe) 2]+ [B(Arf)4]- was carried out. As well a comparison of the structure of [RuH(dppe)2]+ [BPh4]- with that of [Ru([eta]2-H2)H(dppe) 2]+ [BPh4]- showed that minor structural changes occur upon loss of the dihydrogen ligand. The activation of X-H bonds, where X = Si, C, S and O, by reaction with Ru(OTf)(CN)(dppe)2 which contains a highly labile triflate ligand was studied. Many new cationic Ru(II) complexes were prepared and characterized. The X-ray crystal structure of [Ru(CCPh)(CN)(dppe)2] + [OTf]- was determined. Finally, the catalyst precursor RuHCl(PPh3)3 was used to carry out various substitution reactions aimed at determining if the method developed to prepare RuHCl(PPh3)(R-BINAP) could be applied as a general method for the preparation of other complexes containing other chiral and non chiral chelating phosphines. These five coordinate complexes could then be further tested for their ability to act as catalysts in the hydrogenation of ketones and imines.

Download or read book Synthesis and Investigation of Some Cationic and Neutral Ruthenium Dihydrogen and Hydride Complexes written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Some Acidic Ruthenium Dihydrogen and Hydride Complexes written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Reactivity of Aminocyclopentadienyl Ruthenium Complexes written by Thomas Evan Vos and published by . This book was released on 2002 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Heterolytic Splitting of Dihydrogen microform Ruthenium Hydrogenation Catalysts and an Acidity Scale written by Tianshu Li and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equilibrium constants KDM for reactions between acids and bases of phosphorus-containing compounds including phosphonium salts, iron hydrides and ruthenium dihydrogen complexes in CD2Cl 2 (DM) at room temperature are determined by use of 31P and 1H NMR spectroscopy. A continuous scale of pKDM values covering the range 9.7 to -3 is created with acidic compounds [HPR3]BF4 and [FeH(CO)3(PR 3)2]BF4 in CD2Cl2. The crystal structures of [FeH(CO)3(PCy2Ph)2]BF 4 and Fe(CO)3(PCy2Ph)2 are obtained. The new dihydrogen complexes, [Ru(H2)Cl(PPh3)2 (dach)]BF4 (dach = (1R, 2R)-( - )-diaminocyclohexane) and [Ru(H2)Cl{tmeP2(NH)2}]BF4, are prepared and their crystal structures are reported. Their pKDM values are determined to be 8.6 and 6.8, respectively. The heterolytic splitting of dihydrogen in new ruthenium complexes is utilized for the catalytic hydrogenation of the polar bonds in ketones and nitrites. The complex RuHCl{enP2(NH)2} (en = -NHCH2 CH2NH- ) is an active catalyst for nitrile hydrogenation. This catalyst, in combination with Ru(H2)2H2(PCy 3)2, a known catalyst for nitrile hydrogenation, provides very efficient conversion of benzonitrile to benzylamine. The mechanism of the nitrile hydrogenation is proposed. These catalysts are extremely moisture sensitive. The crystal structures of a possible deactivated form of the catalysts, RuH(PhCONH){enP2(NH)2} and RuH(PhCONH){tmeP2(NH) 2}, are reported. The new complex RuH(BH4){enP2(NH) 2} is prepared by RuHCl{enP2(NH)2} and NaBH 4 and its crystal structure was obtained. This is a poor nitrile hydration catalyst. The new tetradentate ligands PPh2C6H4CH=NCMe 2CMe2N=CHC6H4PPh 2 {tmeP2N2} and PPh2C6H 4CH2NHCMe2CMe2NHCH2C 6H4PPh2 {tmeP2(NH)2}, and their ruthenium complexes, trans-RuHCl{tmeP2N 2} and trans-RuHCl{tmeP2(NH)2} (as two isomers), are prepared. The reaction of trans-RuHCl{tmeP 2(NH)2} with KOtBu produces the novel hydridoamido complex RuH{tmeP2NNH}. The reaction of the amido complex with H2 gives, by the heterolytic splitting of dihydrogen, exclusively the dihydridoamine complex trans-Ru(H)2 {tmeP2(NH)2}. The reaction of the amido complex with D2 is also studied. The complex RuH{tmeP2NNH} catalyzes the hydrogenation of acetophenone and a mechanism involving an outer sphere H+/H- transfer to the ketone is proposed. An improved route for the preparation of the phosphine-ketone PPh 2CH2CH2(C=O)Me from PPh2H and CH 2=CH(CO)Me provides an economical and efficient route to the phosphine-hydrazone PPh2CH2CH2(C=N-NH2)Me. The mixture of ruthenium complexes produced from the phosphine-hydrazone catalyzes the hydrogenation of acetophenone to 1-phenylethanol efficiently. The synthesis, structure and preliminary testing of the new precatalyst RuHCl((S, S)-PPM)(PPh3) for ketone hydrogenation are described.

Download or read book Synthesis and Reactivity of Compounds Containing Ruthenium carbon nitrogen and oxygen Bonds written by and published by . This book was released on 1990 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe3)4Ru(X)(Y) and (DMPM)2Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe3)4Ru(Ph)(Me) or (PMe3)4Ru(Ph)2 leads to the ruthenium benzyne complex (PMe3)4Ru([eta]2-C6H4) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO2 and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe3)4Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

Download or read book Investigation of Some Acidic Ruthenium Dihydrogen and Hydride Complexes microform written by Tina Pui Wah Fong and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1999 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dihydrogen and Hydride Complexes of Ruthenium II Synthesis and Properties written by Caroline Theresia Schweitzer and published by . This book was released on 1993 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Reactivity of Molecular Hydrogen Complexes of Ruthenium written by F. M. Conroy-Lewis and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Reactivity of Ruthenium II and Osmium II Organometallic Imido Complexes written by Richard Ira Michelman and published by . This book was released on 1992 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The synthesis and reactivity of some dinuclear compounds of iron and ruthenium written by Clifford Noel Sampson and published by . This book was released on 1984 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Reactivity of Ruthenium and Platinum Complexes with Non dative Heteroatomic Ligands Studies of Carbon hydrogen Bond Activation written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Several ruthenium complexes with non-dative heteroatomic ligands were prepared and fully characterized, including TpRu(PMe3)2X (X = OH, OPh, OMe, SH; Tp = hydridotris(pyrazolyl)borate). At elevated temperatures (90 °C -- 130 °C), complexes of the type TpRu(PMe3)2X (X = OH, OPh, Me, Ph or NHPh) undergo regioselective HD exchange with deuterated arenes. In addition, for X = OH or NHPh, HD exchange occurs at hydroxo and anilido ligands, respectively. For X = OH, OPh, Me, Ph or NHPh, isotopic exchange occurs at the Tp 4-positions with only minimal deuterium incorporation at the Tp 3- or 5-positions. TpRu(PMe3)2Cl, TpRu(PMe3)2OTf (OTf = trifluoromethanesulfonate) and TpRu(PMe3)2SH do not initiate HD exchange in C6D6 after extended periods of time at elevated temperatures. Mechanistic studies indicate that the likely pathway for the HD exchange involves ligand dissociation (PMe3 or NCMe), Ru-mediated activation of an aromatic C-D bond, and deuteration of basic heteroatomic ligand (hydroxo or anilido) or Tp positions via intermolecular D+ transfer. The Ru(II) complexes TpRu(PMe3)2OR (R = H or Ph) react with excess phenylacetylene at elevated temperatures to produce the phenylacetylide complex TpRu(PMe3)2(CðCPh). Kinetic studies indicate that the reaction of TpRu(PMe3)2OH and phenylacetylene likely proceeds through a pathway that involves TpRu(PMe3)2OTf as a catalyst. The reaction of TpRu(PMe3)2OH with 1,4-cyclohexadiene at elevated temperature forms benzene and TpRu(PMe3)2H, while TpRu(PMe3)2OPh does not react with 1,4-cyclohexadiene even after 20 days at 85 °C. The paramagnetic Ru(III) complex [TpRu(PMe3)2OH][OTf] is formed upon single-electron oxidation of TpRu(PMe3)2OH with AgOTf. Reactivity studies suggest that [TpRu(PMe3)2OH][OTf] initiates reactions, including hydrogen atom abstraction, with C-H bonds that have bond dissociation energy d"82 kcalD ol. Experimentally, the O-H bond strength of the Ru(II).