69337-15-1Relevant academic research and scientific papers
Hydride, hydrogen, proton, and electron affinities of imines and their reaction intermediates in acetonitrile and construction of thermodynamic characteristic graphs (TCGs) of imines as a molecule ID card
Zhu, Xiao-Qing,Liu, Qiao-Yun,Chen, Qiang,Mei, Lian-Rui
scheme or table, p. 789 - 808 (2010/04/29)
(Chemical Equation Presented) A series of 61 imines with various typical structures were synthesized, and the thermodynamic affinities (defined as enthalpy changes or redox potentials in this work) of the imines to abstract hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the imines to abstract hydrogen atoms and protons, and the thermodynamic affinities of the hydrogen adducts of the imines to abstract electrons in acetonitrile were determined by using titration calorimetry and electrochemical methods. The pure heterolytic and homolytic dissociation energies of the C=N π-bond in the imines were estimated. The polarity of the C=N double bond in the imines was examined using a linear free-energy relationship. The idea of a thermodynamic characteristic graph (TCG) of imines as an efficient Molecule ID Card was introduced. The TCG can be used to quantitatively diagnose and predict the characteristic chemical properties of imines and their various reaction intermediates as well as the reduction mechanism of the imines. The information disclosed in this work could not only supply a gap of thermodynamics for the chemistry of imines but also strongly promote the fast development of the applications of imines. 2009 American Chemical Society.
KINETICS OF HYDRIDE TRANSFER BETWEEN NITROGEN HETEROAROMATIC CATIONS
Bunting, John W.,Luscher, Mark A.
, p. 2524 - 2531 (2007/10/02)
The kinetics of the reduction of the 3-cyano-1-methylquinolinium, 4-cyano-2-methylisoquinolinium, and 2-methyl-5-nitroisoquinolinium cations by 9,10-dihydro-10-methylacridine, and also the reduction of these same three cations as well as the 10-methylacridinium cation by 5,6-dihydro-5-methylphenanthridine, have been investigated in 20percent acetonitrile - 80percent water, ionic strength 1.0, 25 deg C.The reactions of the 2-methyl-5-nitroisoquinolinium cation with both reductants, and also of the 4-cyano-2-methylisoquinolinium cation with 9,10-dihydro-10-methylacridine, display kinetic saturation effects in the pseudo-first-order rate constants as a function of heterocyclic cation concentration.These effects are consistent with the formation of 1:1 association complexes between hydride donor and acceptor prior to the rate-determining step of the reduction.The second-order rate constants for these reactions, and also those for analogous heterocyclic cation reductions by 1,4-dihydronicotinamides, show systematic variations as a function of the hydride donor and acceptor species.
Kinetics of the Reduction of Isoquinolinium Cations by 1,4-Dihydronicotinamides
Bunting, John W.,Chew, Vivian S. F.,Chu, Gary
, p. 2303 - 2307 (2007/10/02)
The kinetics of the reduction of a series of 2-methyl-4-X-isoquinolinium cations and 2-methyl-5-X-phthalazinium cations by 1-benzyl-1,4-dihydronicotinamide (5) have been measured in 20percent CH3CN-80percent H2O (v/v) at pH 7, 25 deg C, and an ionic strength of 1.0.Pseudo-first-order rate constants (kobsd) show kinetic saturation at high concentrations of 4 (X = H and Br), and association constants of 2.1 and 1.5 M-1, respectively, have been evaluated for 1:1 complex formation.Interpretation of these data and earlier data for the reduction of the 2-methyl-5-nitroisoquinolinium cation (3) in terms of nonproductive complex formation leads to a linear free-energy relationship between the second-order rate constant (k2) for reduction and pKR+ for pseudobase formation by these cations: log k2 = -0.50pKR+ + 4.9.Substituent effects upon k2 for the reduction of 3 and 4 (X = CONH2, CN) by 1-benzyl-3-W-1,4-dihydropyridines (W = CN, CONH2, CONHCH3, CON(CH3)2) are similar to the substituent effects for cyanide ion dissociation from the corresponding 1-benzyl-4-cyano-3-W-1,4-dihydropyridines.The current study indicates that the relatively strong 1:1 complexes observed in the reduction of 5-nitroisoquinolinium cations by 1,4-dihydronicotinamides are nonproductive and also provides further evidence in support of a one-step hydride-transfer mechanism for these reactions.
Kinetics and Mechanism of the Reaction of 5-Nitroisoquinolinium Cations with 1,4-Dihydronicotinamides
Bunting, John W.,Sindhuatmadja, Shinta
, p. 4211 - 4219 (2007/10/02)
The kinetics of the reduction of 2-methyl- (7) and 2-(Z-benzyl)-5-nitroisoquinolinium cations (2) by 1-(X-benzyl)-1,4-dihydronicotinamides (1) to give the corresponding 1,2-dihydro-5-nitroisoquinolines have been studied in 20percent acetonitrile-80percent
