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Ether Complexes (ether + complex)
Selected AbstractsChemInform Abstract: Synthesis of (E)-Stilbenes and (E,E)-1,4-Diphenylbuta-1,3-diene Promoted by Boron Trifluoride,Diethyl Ether Complex.CHEMINFORM, Issue 14 2010T. Narender 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] Unexpected Structural Diversity in Alkali Metal Azide-Crown Ether Complexes: Syntheses, X-ray Structures, and Quantum-Chemical CalculationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2006Michael D. Brown Abstract A series of alkali metal azide-crown ether complexes, [Li([12]crown-4)(N3)], [Na([15]crown-5)(N3)], [Na([15]crown-5)(H2O)2]N3, [K([18]crown-6)(N3)(H2O)], [Rb([18]crown-6)(N3)(H2O)], [Cs([18]crown-6)(N3)]2, and [Cs([18]crown-6)(N3)(H2O)(MeOH)], has been synthesised. In most cases, single crystals were obtained, which allowed X-ray crystal structures to be derived. The structures obtained have been compared with molecular structures computed by density functional theory (DFT) calculations. This has allowed the effects of the crystal lattice on the structures to be investigated. Also, a study of the MNterminal metal,azide bond length and charge densities on the metal (M) and terminal nitrogen centre (Nterminal) in these complexes has allowed the nature of the metal,azide bond to be probed in each case. The bonding in these complexes is believed to be predominantly ionic or ion-dipole in character, with the differences in geometries reflecting the balance between maximising the coordination number of the metal centre and minimising ligand-ligand repulsions. The structures of the crown ether complexes determined in this work show the subtle interplay of such factors. The significant role of hydrogen bonding is also demonstrated, most clearly in the structures of the K and Rb dimers, but also in the chain structure of the hydrated Cs complex. [source] Synthesis of (Vinylidene)- and (Cyclopropenyl)ruthenium Complexes Containing a Tris(pyrazolyl)borato (Tp) LigandEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2004Yih-Hsing Lo Abstract A convenient high-yield route to [Ru(C,C,Ph)(Tp)(PPh3)2] [2; Tp = HB(pz)3, pz = pyrazolyl] has been found through the intermediacy of [RuCl2(Hpz)2(PPh3)2] (1). This complex is readily obtained on treatment of [RuCl2(PPh3)3] with 2 equiv. of pyrazole in boiling THF. The molecular structures of complexes 1 and 2 have been confirmed by single-crystal X-ray diffraction analysis. A number of new cationic vinylidene complexes [Ru{=C=C(Ph)CH2R}(Tp)(PPh3)2]+ [3a, R = CN; 3b, R = HC=CH2; 3c, R = CH=C(CH3)2; 3d, R = Ph; 3e, R = C(O)OMe] have been prepared by electrophilic addition of organic halides to complex 2. The deprotonation reaction of 3a yields the cyclopropenyl complex 4a. One phosphane ligand of 4a is remarkably labile, being replaced by donor ligands L to yield diastereomeric mixtures of the cyclopropenyl complexes 5a,5d mostly in an approximate 4:1 ratio. The cyclopropenyl rings in 4a and 5a are susceptible to ring opening by I2. In addition, treatment of 4a with nBuNC in the presence of MeOH results in substitution of a phosphane ligand by nBuNC followed by protonation of the three-membered ring by MeOH. This is then followed by addition of methoxide to give the vinyl ether complex [Ru{C(OMe)=C(Ph)CH2CN}(Tp)(PPh3)(nBuNC)] (8a). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Investigation of ion-pair precipitates of selected alkoxylates and complex salts of specific metal cations by liquid secondary ion mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2002Abstract Liquid secondary ion (LSI) mass spectra of ion-pair precipitates obtained for Triton X-100 with strontium, lead, cadmium and mercury tetraphenylborates and for selected butoxylene,ethoxylene monoalkyl ethers with barium tetraiodobismuthate(III) are discussed. On the basis of LSI mass spectra, recorded in both positive and negative modes, the formulae of the ion-pair precipitates were determined. On the basis of B/E mass spectra, the fragmentation routes of [M , H + Ba]+ ions for butoxylene,ethoxylene monoalkyl ether complexes of barium and [M , H + Cd]+ ions for the Triton X-100 complex of cadmium are proposed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Unexpected Structural Diversity in Alkali Metal Azide-Crown Ether Complexes: Syntheses, X-ray Structures, and Quantum-Chemical CalculationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2006Michael D. Brown Abstract A series of alkali metal azide-crown ether complexes, [Li([12]crown-4)(N3)], [Na([15]crown-5)(N3)], [Na([15]crown-5)(H2O)2]N3, [K([18]crown-6)(N3)(H2O)], [Rb([18]crown-6)(N3)(H2O)], [Cs([18]crown-6)(N3)]2, and [Cs([18]crown-6)(N3)(H2O)(MeOH)], has been synthesised. In most cases, single crystals were obtained, which allowed X-ray crystal structures to be derived. The structures obtained have been compared with molecular structures computed by density functional theory (DFT) calculations. This has allowed the effects of the crystal lattice on the structures to be investigated. Also, a study of the MNterminal metal,azide bond length and charge densities on the metal (M) and terminal nitrogen centre (Nterminal) in these complexes has allowed the nature of the metal,azide bond to be probed in each case. The bonding in these complexes is believed to be predominantly ionic or ion-dipole in character, with the differences in geometries reflecting the balance between maximising the coordination number of the metal centre and minimising ligand-ligand repulsions. The structures of the crown ether complexes determined in this work show the subtle interplay of such factors. The significant role of hydrogen bonding is also demonstrated, most clearly in the structures of the K and Rb dimers, but also in the chain structure of the hydrated Cs complex. [source] | ||||||||||