Search results for " Anions"
showing 8 items of 18 documents
NMR enantiodifferentiation of triphenylphosphonium salts by chiral hexacoordinated phosphate anions
2003
BINPHAT anion—rather than TRISPHAT—is an efficient NMR chiral shift reagent for triphenylphosphonium salts containing stereogenic centers on the aliphatic side-chain. BINPHAT—rather than TRISPHAT—anion is an efficient NMR (1H and 31P) chiral shift reagent for chiral triphenylphosphonium salts.
Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd3(3-CO)(dppm)3]2+ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of a…
2006
The title cluster, [Pd(3)(mu(3)-CO)(dppm)(3)](2+) (dppm=bis(diphenylphosphino)methane), reacts with one equivalent of hydroxide anions (OH(-)), from tetrabutylammonium hydroxide (Bu(4)NOH), to give the paramagnetic [Pd(3)(mu(3)-CO)(dppm)(3)](+) species. Reaction with another equivalent of OH(-) leads to the zero-valent compound [Pd(3)(mu(3)-CO)(dppm)(3)](0). From electron paramagnetic resonance analysis of the reaction medium using the spin-trap agent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), the 2-tetrahydrofuryl or methyl radicals, deriving from the tetrahydrofuran (THF) or dimethyl sulfoxide (DMSO) solvent, respectively, were detected. For both [Pd(3)(mu(3)-CO)(dppm)(3)](2+) and [Pd(3)(mu…
Synthesis, Characterization, and Properties of Weakly Coordinating Anions Based on tris-Perfluoro-tert-Butoxyborane
2017
A convenient method for the preparation of strongly Lewis acidic tris-perfluoro-tert-butoxyborane B(ORF)3 (1), (ORF = OC(CF3)3) was developed, and its X-ray structure was determined. 1 was used as a precursor, guided by density functional theory (DFT) calculations and volume-based thermodynamics, for the synthesis of [NEt4][NCB(ORF)3] (3) and [NMe4][FB(ORF)3] (5) and the novel large and weakly coordinating anion salts [Li 15-Crown-5][B(ORF)4] (2) and [NEt4][CN{B(ORF)3}2] (4). The stability of [B(ORF)4]− was compared with that of some related known weakly coordinating anions by appropriate DFT calculations.
Computational investigations of 18-electron triatomic sulfur–nitrogen anions
2018
MRCI-SD/def2-QZVP and PBE0/def2-QZVP calculations have been employed for the analysis of geometries, stabilities, and bonding of isomers of the 18-electron anions N2S2−, NS2−, and NSO−. Isomers of the isoelectronic neutral molecules SO2, S2O, S3, and O3 are included for comparison. The sulfur-centered acyclic NSN2−, NSS−, and NSO− anions are the most stable isomers of their respective molecular compositions. However, the nitrogen-centered isomers SNS− and SNO− lie close enough in energy to their more stable counterparts to allow their occurrence. The experimental structural information, where available, is in good agreement with the optimized bond parameters. The bonding in all investigate…
Influence of the nature of the substrate and of operative parameters in the electrocarboxylation of halogenated acetophenones and benzophenones
2005
Abstract The electrocarboxylation of halogenated acetophenones and benzophenones to the corresponding hydroxycarboxylic acids has been carried out in undivided cell equipped with aluminium sacrificial anode and using 1-methyl-2-pyrrolidinone (NMP) as the solvent. The radical anion generated by the electro-reduction of the aromatic ketone is involved in several competitive reactions which lead to the formation of the target hydroxycarboxylic acid, the corresponding alcohol and pinacol and the de-halogenated parent ketone. If sufficiently negative working potentials are imposed, the latter is reduced to the corresponding carboxylate, pinacol and alcohol. Very different results in terms of sel…
Crystal structure of [tris(4,4-bipyridine)]diium bis(1,1,3,3-tetracyano-2-ethoxypropenide) trihydrate
2016
In the title hydrated salt, which was obtained from the hydrothermal reaction between between potassium 1,1,3,3-tetracyano-2-ethoxypropenide and 4,4′-bipyridine in the presence of iron(II) sulfate heptahydrate, the ionic components are linked into a three-dimensional network by C—H⋯N hydrogen bonds.
Polymorphism and Metallic Behavior in BEDT-TTF Radical Salts with Polycyano Anions
2012
Up to five different crystalline radical salts have been prepared with the organic donor BEDT-TTF and three different polynitrile anions. With the polynitrile dianion tcpd2− (=C[C(CN)2]32−), two closely related radical salts: α'-(ET)4tcpd·THF (1) (THF = tetrahydrofurane) and α'-(ET)4tcpd·H2O (2) have been prepared, depending on the solvent used in the synthesis. With the mono-anion tcnoetOH− (=[(NC)2CC(OCH2CH2OH)C(CN)2]−) two polymorphs with similar physical properties but different crystal packings have been synthesized: θ-(ET)2(tcnoetOH) (3) and β''-(ET)2(tcnoetOH) (4). Finally, with the mono-anion tcnoprOH− (=[(NC)2CC(OCH2CH2CH2OH)C(CN)2]−) we have prepared a metallic…
Synthesis, Characterization, and Properties of Weakly Coordinating Anions Based on tris-Perfluoro-tert-Butoxyborane
2017
Abstract Image A convenient method for the preparation of strongly Lewis acidic tris-perfluoro-tert-butoxyborane B(ORF)3 (1), (ORF = OC(CF3)3) was developed, and its X-ray structure was determined. 1 was used as a precursor, guided by density functional theory (DFT) calculations and volume-based thermodynamics, for the synthesis of [NEt4][NCB(ORF)3] (3) and [NMe4][FB(ORF)3] (5) and the novel large and weakly coordinating anion salts [Li 15-Crown-5][B(ORF)4] (2) and [NEt4][CN{B(ORF)3}2] (4). The stability of [B(ORF)4]− was compared with that of some related known weakly coordinating anions by appropriate DFT calculations. peerReviewed