1122-59-4Relevant articles and documents
Hydrogen bond formation and molecular motion in solutions of aniline with nitroxide free radicals
Stark,Mueller-Warmuth
, p. 168 - 172 (1990)
1H NMR spin-lattice relaxation rates and paramagnetic contact shifts have been measured at various temperatures and frequencies in solutions of aniline, aniline-d2, and aniline-d5 containing nitroxide free radicals. The data can be explained in terms of transient hydrogen bond formation between the amino protons and the NO groups of the radical. Detailed information about the intermolecular transfer of electron spin density and the steric arrangement of the complex have been obtained. Molecular motions and interactions have been probed by relaxation measurements over a large frequency range between 100 kHz and 300 MHz. The results are compared with other hydrogen-bonded complexes of nitroxide radicals and proton donor solvent molecules.
Brownlee,R.T.C. et al.
, p. 1757 - 1767 (1968)
Brink,Bayles
, p. 835,836,837 (1974)
Ultrafast forward and backward electron transfer dynamics of coumarin 337 in hydrogen-bonded anilines as studied with femtosecond UV-pump/IR-probe spectroscopy
Ghosh, Hirendra N.,Verma, Sandeep,Nibbering, Erik T. J.
, p. 664 - 670 (2011)
Femtosecond infrared spectroscopy is used to study both forward and backward electron transfer (ET) dynamics between coumarin 337 (C337) and the aromatic amine solvents aniline (AN), N-methylaniline (MAN), and N,N-dimethylaniline (DMAN), where all the aniline solvents can donate an electron but only AN and MAN can form hydrogen bonds with C337. The formation of a hydrogen bond with AN and MAN is confirmed with steady state FT-IR spectroscopy, where the C= O stretching vibration is a direct marker mode for hydrogen bond formation. Transient IR absorption measurements in all solvents show an absorption band at 2166 cm-1, which has been attributed to the C≡N stretching vibration of the C337 radical anion formed after ET. Forward electron transfer dynamics is found to be biexponential with time constants τET1 = 500 fs, τET 2 = 7 ps in all solvents. Despite the presence of hydrogen bonds of C337 with the solvents AN and MAN, no effect has been found on the forward electron transfer step. Because of the absence of an H/D isotope effect on the forward electron transfer reaction of C337 in AN, hydrogen bonds are understood to play a minor role in mediating electron transfer. In contrast, direct π-orbital overlap between C337 and the aromatic amine solvents causes ultrafast forward electron transfer dynamics. Backward electron transfer dynamics, in contrast, is dependent on the solvent used. Standard Marcus theory explains the observed backward electron transfer rates.
Visible light-driven selective hydrogenation of unsaturated aromatics in an aqueous solution by direct photocatalysis of Au nanoparticles
Huang, Yiming,Liu, Zhe,Gao, Guoping,Xiao, Qi,Martens, Wayde,Du, Aijun,Sarina, Sarina,Guo, Cheng,Zhu, Huaiyong
, p. 726 - 734 (2018/02/14)
Selective hydrogenation of various chemical bonds, such as CC, CC, CO, NO, and CN, is efficiently driven by visible light over a supported gold nanoparticle (AuNP) photocatalyst under mild reaction conditions. The reaction system exhibits high substituent tolerance and tunable selectivity by light wavelength. Density functional theory (DFT) calculations demonstrated a strong chemisorption between the reactant molecule and metal resulting in hybridized orbitals. It is proposed that direct photoexcitation between hybridized orbitals is the main driving force of the hydrogenation reaction. The hydrogenation pathway is investigated by the isotope tracking technique. We revealed the cooperation of water and formic acid (FA) as a hydrogen source and the hydrogenation route through Au-H species on the AuNP surface.
Mechanistic insights into the Pd-catalyzed direct amination of allyl alcohols: Evidence for an outer-sphere mechanism involving a palladium hydride intermediate
Sawadjoon, Supaporn,Sjoeberg, Per J. R.,Orthaber, Andreas,Matsson, Olle,Samec, Joseph S. M.
supporting information, p. 1520 - 1524 (2014/03/21)
The mechanism of direct amination of allyl alcohol by a palladium triphenylphosphite complex has been explored. Labelling studies show that the reaction proceeds through a π-allylpalladium intermediate. A second-order dependence of reaction rate on allyl alcohol concentration was observed. Kinetic isotope effect studies and ESI-MS studies are in agreement with a reaction proceeding through a palladium hydride intermediate in which both O-H bond and C-O bond cleavages are involved in rate-determining steps. A stereochemical study supports an outer-sphere nucleophilic attack of the π-allylpalladium intermediate giving complete chiral transfer from starting material to product. Two cleavages: The mechanism of the direct amination of allyl alcohol by palladium complexes bearing triphenylphosphite ligands has been explored. Kinetic isotope and ESI-MS studies are in good agreement with that both Oi￡H bond and Ci￡O bond cleavages are involved in rate-determining steps. Furthermore, stereochemical studies support an outer-sphere nucleophilic attack of the π-allylpalladium intermediate. Copyright
