61777-43-3Relevant academic research and scientific papers
Thermodynamic diagnosis of the properties and mechanism of dihydropyridine-type compounds as hydride source in acetonitrile with molecule id card
Zhu, Xiao-Qing,Tan, Yue,Cao, Chao-Tun
scheme or table, p. 2058 - 2075 (2010/07/16)
A series of 45 dihydropyridine-type organic compounds as hydride source were designed and synthesized. The thermodynamic driving forces (defined as enthalpy changes or redox potentials in this work) of the dihydropyridines to release hydride anions, hydrogen atoms (hydrogen for short), and electrons in acetonitrile,the thermodynamic driving forces of the radical cations of the dihydropyridines to release protons and hydrogens in acetonitrile, and the thermodynamic driving forces of the neutral pyridine-type radicals of the dihydropyridines to release electron in acetonitrile were determined by using titration calorimetry and electrochemical methods. The rates and activation parameters of hydride transfer from the dihydropyridines to acridinium perclorate, a well-known hydride acceptor, were determined by using UV-vis absorption spectroscopy technique. The relationship between the thermodynamic driving forces and kinetic rate of the hydride transfer was examined. Thermodynamic characteristic graph (TCG) of the dihydropyridines as an efficient Molecule ID Card was introduced. The TCG can be used to quantitatively diagnose or predict the characteristic chemical properties of the dihydropyridines and their various reaction intermediates. The mechanism of hydride transfer from the dihydropyridines to acridinium perclorate was diagnosed and elucidated by using the determined thermodynamic parameters and the activation parameters..
Energetic Comparison between Photoinduced Electron-Transfer Reactions from NADH Model Compounds to Organic and Inorganic Oxidants and Hydride-Transfer Reactions from NADH Model Compounds to p-Benzoquinone Derivatives
Fukuzumi, Shunichi,Koumitsu, Shintaro,Hironaka, Katsuhiko,Tanaka, Toshio
, p. 305 - 316 (2007/10/02)
Kinetics studies on photoinduced electron-transfer reactions from dihydropyridine compounds (PyH2) as being NADH model compounds to organic and inorganic oxidants and hydride-transfer reactions from PyH2 to p-benzoquinone derivatives (Q) in the absence and presence of Mg2+ ion are reported by determining over 150 rate constants.These results, combined with the values of Gibbs energy change of the photoinduced electron-transfer reactions as well as those of each step of the hydride-transfer reactions as being the e--H+-e- sequence, which are determined independently, revealed that the rate constants of the photoinduced electron-transfer reactions obey the Rehm-Weller-Gibbs energy relationship and that the activation barrier of the hydride-transfer reactions from PyH2 to Q is dependent solely on the Gibbs energy changes of the initial electron transfer from PyH2 to Q and the following proton transfer from PyH2.+ to Q.- and thus independent of the Gibbs energy change of the final electron transfer from PyH. to QH..The retarding effect of Mg2+ ion observed on the photoinduced electron transfer and hydride-transfer reactions of PyH2 is ascribed to the positive shifts of the redox potentials of the ground and excited states of PyH2 due to the complex formation with Mg2+ ion.
