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Hydride
Kinds of Hydride Terms modified by Hydride Selected AbstractsSynthesis and Characterization of a New Guanidine,Borane Complex and a Dinuclear Boron(II) Hydride with Bridging Guanidinate LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2007Oxana Ciobanu Abstract We report the synthesis and structural characterization of the new monomeric borane complex H3B·hppH (hppH = 1,3,4,6,7,8-hexahydro-2H -pyrimido[1,2- a]pyrimidine), which represents the first example of a structurally characterized 1:1 complex between hppH and a group 13 element hydride. Significant intramolecular and, in the crystalline phase, intermolecular H···H contacts are established in this complex. It is shown that the complex can be used as a precursor to new dinuclear boron(II) compounds featuring a B,B single bond. Thus H2 elimination followed by dimerization of H3B·hppH leads to [(hpp)BH]2 with two bridging hpp units. The structural details derived from X-ray diffraction measurements are reported.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Diisobutylaluminium Hydride (DIBAL-H) Promoted Secondary Rim Regioselective Demethylations of Permethylated ,-Cyclodextrin: A Mechanistic ProposalEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2010Sulong Xiao Abstract Diisobutylaluminium hydride (DIBAL-H) promotes secondary rim regioselective bis-de- O -methylation at the 2A - and 3B -positions of permethylated ,-cyclodextrin. This result contrasts with the selective bis-de- O -benzylation of perbenzylated cyclodextrins in which regioselective deprotection occurs at the primary rim. To gain an insight into the mechanism of this remarkable contrasting behavior, the two corresponding permethylated cyclodextrins with an alcohol function at either the 2- or 3-position were synthesized. The cyclodextrin with the alcohol at the 3-position reacts withDIBAL-H to afford the 2A,3B -diol whereas the cyclodextrin with the alcohol at the 2-position is unreactive. This observation allows us to propose a mechanism for the demethylation reaction that involves for each demethylation step two molecules of aluminium reagent, in accord with the previous hypothesis on the debenzylation reaction. The second demethylation step appears to be faster than the first, the coordination of aluminium now being an intramolecular process. [source] Hydride-based silica stationary phases for HPLC: Fundamental properties and applicationsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2005Joseph J. Pesek Abstract Silica hydride is a recent development in chromatographic support materials for HPLC where hydride groups replace 95% of the silanols on the surface. This conversion changes many of the fundamental properties of the material as well as the bonded stationary phases that are the result of further chemical modification of the hydride surface. The general approach for fabricating the silica hydride and subsequent bonded phases is reviewed. Properties of the silica hydride surface are compared to those of the standard material obtained in the preparation of most commercial HPLC stationary phases. Some unique chromatographic properties of hydride-based phases are described as well as some general application areas where these bonded materials may be used in preference to or have advantages not available from typical stationary phases. [source] Reduction of a Chelating Bis(NHC) Palladium(II) Complex to [{,-bis(NHC)}2Pd2H]+: A Terminal Hydride in a Binuclear Palladium(I) Species Formed under Catalytically Relevant Conditions,ANGEWANDTE CHEMIE, Issue 36 2010Peter Durch basenunterstützte Reduktion einer Palladium(II)-Vorstufe wurde der erste Palladium(I)-NHC-Komplex (NHC=N-heterocyclisches Carben) in hoher Ausbeute hergestellt und isoliert. Die Position des einzigartigen terminalen Hydridliganden (siehe Bild; PdI,cyan, H,weiß, N,blau) wurde durch Neutronenbeugung am Einkristall bestimmt, und das fluktuierende Verhalten des Komplexes in Lösung wurde untersucht. [source] ChemInform Abstract: Potassium Hydride in Paraffin: A Useful Base for Williamson Ether Synthesis.CHEMINFORM, Issue 39 2010Haihong Huang Abstract A procedure for the preparation of KH in paraffin from potassium metal and hydrogen is developed. [source] ChemInform Abstract: Direct Amide Synthesis from Either Alcohols or Aldehydes with Amines: Activity of Ru(II) Hydride and Ru(0) Complexes.CHEMINFORM, Issue 36 2010Senthilkumar Muthaiah Abstract The combination of RuH2(PPh3)4 with NHC, MeCN, and NaH provides an efficient system which allows direct synthesis of amides from either alcohols or aldehydes. [source] ChemInform Abstract: Tributyltin Hydride in NMP-Promoted Reduction of Acid Chlorides to Aldehydes under Transition-Metal-Free Conditions.CHEMINFORM, Issue 34 2010Patrick Le Menez Abstract A simple and general procedure uses Bu3SnH in NMP for the partial reduction of the acid chloride substrates. [source] ChemInform Abstract: Lewis Acidities and Hydride, Fluoride, and X - Affinities of the BH3-nXn Compounds for (X: F, Cl, Br, I, NH2, OH, and SH) from Coupled Cluster Theory.CHEMINFORM, Issue 47 2009Daniel J. Grant Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Generation of Hafnium Hydride and Its Application to Chemo- and Diastereoselective Reactions.CHEMINFORM, Issue 43 2009Ikuya Shibata Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: A One-Pot, Stereoselective Synthesis of 2-Ethoxycarbonyl-Substituted 1,3-Dienes and 1,3-Enynes by Hydrostannylation , Stille Tandem Reaction of Tributyltin Hydride with Alkynyl Esters and Alkenyl or Alkynyl Halides.CHEMINFORM, Issue 41 2009Mingzhong Cai Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Aluminum Hydride: A Reversible Material for Hydrogen Storage.CHEMINFORM, Issue 38 2009Ragaiy Zidan Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Ammonia Borane Destabilized by Lithium Hydride: An Advanced On-Board Hydrogen Storage Material.CHEMINFORM, Issue 44 2008Xiangdong Kang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Palladium(II)-Catalyzed Isomerization of Olefins with Tributyltin Hydride.CHEMINFORM, Issue 49 2007In Su Kim Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Tributyltin Hydride Mediated Straightforward Synthesis of a New Isoxazolo-benzazulene Ring System.CHEMINFORM, Issue 1 2007Vijay Singh Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] A First-Principles Study of the Electronic Structure and Stability of a Lithium Aluminum Hydride for Hydrogen Storage.CHEMINFORM, Issue 30 2006Y. Song Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Radical Reduction of Aromatic Azides to Amines with Tributylgermanium Hydride.CHEMINFORM, Issue 22 2006Luisa Benati Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Stereoselective Synthesis of Stannyl Enones via Palladium-Catalyzed and Free Radical Hydrostannation of Alkynyl Ketones with Trineophyltin Hydride.CHEMINFORM, Issue 21 2004Veronica I. Dodero Abstract For Abstract see ChemInform Abstract in Full Text. [source] Transformation of Carboxylic Esters to Aldehydes with Lithium N,N,-Dimethylethylenediaminoaluminum Hydride.CHEMINFORM, Issue 23 2003Jin Soon Cha Abstract For Abstract see ChemInform Abstract in Full Text. [source] Reaction of Carbonyl Compounds with Trialkylsilyl Phenylselenide and Tributylstannyl Hydride under Radical Conditions.CHEMINFORM, Issue 2 2003Yutaka Nishiyama Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Selective ,-Stannylated Addition of Di-n-butyliodotin Hydride Ate Complex to Simple Aliphatic Alkynes.CHEMINFORM, Issue 34 2001Ikuya Shibata Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Hydrocarbon-Soluble Calcium Hydride: A "Worker-Bee" in Calcium ChemistryCHEMISTRY - A EUROPEAN JOURNAL, Issue 32 2007Jan Spielmann Abstract The reactivity of the hydrocarbon-soluble calcium hydride complex [{CaH(dipp-nacnac)(thf)}2] (1; dipp-nacnac=CH{(CMe)(2,6- iPr2C6H3N)}2) with a large variety of substrates has been investigated. Addition of 1 to CO and CN functionalities gave easy access to calcium alkoxide and amide complexes. Similarly, reduction of the CN bond in a cyanide or an isocyanide resulted in the first calcium aldimide complexes [Ca{NC(H)R}(dipp-nacnac)] and [Ca{C(H)NR}(dipp-nacnac)], respectively. Complexation of 1 with borane or alane Lewis acids gave the borates and alanates as contact ion pairs. In reaction with epoxides, nucleophilic ring-opening is observed as the major reaction. The high reactivity of hydrocarbon-soluble 1 with most functional groups contrasts strongly with that of insoluble CaH2, which is essentially inert and is used as a common drying agent. Crystal structures of the following products are presented: [{Ca{OC(H)Ph2}(dipp-nacnac)}2], [{Ca{NC(H)Ph}(dipp-nacnac)}2], [{Ca{C(H)NC(Me)2CH2C(Me)3}(dipp-nacnac)}2], [{Ca{C(H)NCy}(dipp-nacnac)}2], [Ca(dipp-nacnac)(thf)]+[H2BC8H14], and [{Ca(OCy)(dipp-nacnac)}2]. The generally smooth and clean conversions of 1 with a variety of substrates and the stability of most intermediates against ligand exchange make 1 a valuable key precursor in the syntheses of a wide variety of ,-diketiminate calcium complexes. [source] Solid-State Structures and Properties of Europium and Samarium HydridesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2010Holger Kohlmann Abstract The structural chemistry of europium and samarium hydrides in the solid state is very rich, ranging from typical ionic hydrides following the hydride-fluoride analogy to complex transition metal hydrides and interstitial hydrides. While crystal structure, electrical, and magnetic properties suggest that europium is divalent in all hydrides investigated so far, samarium is easily transformed to a trivalent oxidation state in its hydrides and shows similarities to other lanthanide(III) hydrides. The problem of neutron absorption of europium and samarium, hampering crystal structure solution and limiting the available structural information, is discussed in detail, and practical solutions for neutron diffraction experiments are given. [source] Calculated Enthalpies for Dimerisation of Binary, Unsaturated, Main-Group Element Hydrides as a Means to Analyse Their Potential for Multiple BondingEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2003Hans-Jörg Himmel Abstract Herein, the dimerisation of subvalent, binary, main-group element hydrides with the potential for multiple bonding is studied using both hybrid DFT (B3LYP) and ab initio [MP2 and CCSD(T)] methods. The [2+2] cycloaddition is an important and characteristic reaction of derivatives of ethylene. A comparison of dimerisation reactions for several compounds with the potential for multiple bonding should, therefore, shed light on the properties of these species. Our study includes the hydrides E2H2 (E = B, Al, Ga, N P or As), E2H4 (E = C, Si or Ge) and ENH4 (E = B, Al or Ga) and their dimers. Several isomeric forms of the monomers and dimers have to be considered. The trends within a group and a period are established and the factors responsible for them are discussed. It turns out that, generally, the enthalpies for dimerisation increase for heavier homologues, reflecting that the most important factor is the reduced strength of the E,E bonds in the monomers prior to dimerisation and, to some degree, also the reduced ring strain in the cyclic dimers. The exceptions are the dimerisations of B2H2 and Al2H2, both of which lead to the tetrahedral E4H4 species (E = B or Al). Dimerisation of Al2H2 is associated with a smaller enthalpy than that for the dimerisation of B2H2. Comparisons and analyses are made complicated because of the changes in the structures of the isomeric global minima between homologues. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Improving the Hydrogen Reaction Kinetics of Complex HydridesADVANCED MATERIALS, Issue 29 2009Jun Yang Abstract Alanates, borohydrides, and amides are complex hydrides with high concentration hydrogen that have been actively investigated for materials-based hydrogen storage on-board polymer electrolyte membrane fuel cell (PEMFC) vehicle applications. The major challenge is to release hydrogen at fuel cell working temperature range at fast enough rate without simultaneous desorption of fuel cell poisoning impurities. We review recent progress in hydrogen reaction mechanism and schemes for complex hydride hydrogen storage. [source] ChemInform Abstract: Reversible Hydriding/Dehydriding Properties of New Y3Al2 Hydrides.CHEMINFORM, Issue 22 2009K. Ikeda Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Polyanionic Gallium Hydrides from AlB2 -Type Precursors AeGaE (Ae: Ca, Sr, Ba; E: Si, Ge, Sn).CHEMINFORM, Issue 51 2008Michael J. Evans Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Density Functional Study of Small Neutral and Charged Silver Cluster Hydrides.CHEMINFORM, Issue 52 2006Shuang Zhao Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Structural Investigations of Two New Ternary Magnesium,Niobium Hydrides, Mg6.5NbH,14 and MgNb2H,4.CHEMINFORM, Issue 36 2006Toyoto Sato Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Neutron Diffraction Investigations and Magnetic Properties of LnNi3.5Al1.5 Compounds and Their Hydrides (Deuterides).CHEMINFORM, Issue 10 2006M. Bououdina Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Structure and Magnetism of a New Series of UTSn Hydrides.CHEMINFORM, Issue 10 2006K. Miliyanchuk Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] | ||||||||||||||||||||||||||||||||||||||||