Electron and hole interactions with P, Z, and P:Z and the formation of mutagenic products by proton transfer reactions

2020 ◽  
Vol 22 (2) ◽  
pp. 919-931
Author(s):  
N. R. Jena
Keyword(s):  
Proton Transfer ◽  
Electron Acceptor ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Proton Transfer Reactions

Z would act as an electron acceptor and P would capture a hole in the unnatural DNA. The latter process would produce mutagenic products via a proton transfer reaction.

Intermolecular proton shuttling in excited state proton transfer reactions: insights from theory

2014 ◽  
Vol 16 (18) ◽  
pp. 8661-8666 ◽  
Author(s):  
Marika Savarese ◽  
Paolo A. Netti ◽  
Nadia Rega ◽  
Carlo Adamo ◽  
Ilaria Ciofini
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Td Dft ◽  
Excited State Proton Transfer ◽  
Proton Transfer Reactions ◽  
Proton Shuttling

The mechanism of intermolecular proton shuttling involved in a prototypical excited state proton transfer reaction is disclosed using DFT and TD-DFT.

Base-Cataytic Properties of Solid Silicon Imidonitrides

2002 ◽  
Vol 731 ◽  
Author(s):  
Peter Kroll ◽  
Dirk Mertens
Keyword(s):  
Proton Transfer ◽  
Density Functional ◽  
Transfer Reaction ◽  
Internal Surface ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Dynamic Simulations ◽  
Density Functional Methods ◽  
Functional Methods ◽  
Proton Transfer Reactions

AbstractStructural models of silicon imidonitride (SiNH) solids are studied using density functional methods. The porous models have densities between 1.6 and 2.4 g/cm3 with pore sizes between 4.5 Å and 7.5 Å. The networks consist of Si-N and N-H bonds only, with N-H and N-H2 groups located at the internal surface. Calculated Raman spectra compare very well with experimental results. We observed proton transfer reactions from an inserted malononitrile molecule to the SiNH-host during Car-Parrinello molecular dynamic simulations. The proton affinity of porous silicon imidonitride structures is confirmed by an energy gain for the proton transfer reaction to both N-H and N-H2 groups.

Enhanced CO2 uptake by intramolecular proton transfer reactions in amino-functionalized pyridine-based ILs

2017 ◽  
Vol 53 (44) ◽  
pp. 5950-5953 ◽  
Author(s):  
Mingguang Pan ◽  
R. Vijayaraghavan ◽  
Fengling Zhou ◽  
Mega Kar ◽  
Haoran Li ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Intramolecular Proton Transfer ◽  
Transfer Reactions ◽  
Co2 Uptake ◽  
Functionalized Pyridine ◽  
New Strategy ◽  
Proton Transfer Reactions

This work presents a new strategy for the promotion of CO2 uptake by an intramolecular proton transfer reaction in amino functionalized hydroxypyridine based anions.

Kinetics and isotope effects of the proton transfer reactions between 1-(4-nitrophenyl)-1-nitroethane to phenyltetramethylguanidine in dipolar aprotic solvents

1984 ◽  
Vol 62 (5) ◽  
pp. 954-957 ◽  
Author(s):  
Arnold Jarczewski ◽  
Przemyslaw Pruszynski ◽  
Mohammed Kazi ◽  
Kenneth T. Leffek
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Isotope Effects ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Aprotic Solvents ◽  
Enthalpy Of Activation ◽  
Proton Transfer Reactions ◽  
Carbon Acid ◽  
Dipolar Aprotic Solvents

The carbon acid 1-(4-nitrophenyl)-1-nitroethane reacts with phenyltetramethylguanidine in the aprotic solvents acetonitrile, benzonitrile, and chlorobenzene in a bimolecular proton transfer reaction. The primary isotope effects, kH/kD, for these reactions at 25 °C are 8.5 ± 0.4, 6.1 ± 0.4, and 16 in acetonitrile, benzonitrile, and chlorobenzene respectively. The magnitude of the isotope effects on the enthalpy of activation [Formula: see text] are 2.3 ± 0.2, 1.6 ± 0.7, and 4.2 ± 0.6 kcal mol−1, which indicates a contribution from proton tunnelling to the reaction rate of the normal substrate.

Kinetic study of the proton transfer reaction between 1-nitro-1-(4-nitrophenyl)alkanes and TBD and MTBD bases in acetonitrile solvent

2001 ◽  
Vol 79 (7) ◽  
pp. 1128-1134 ◽  
Author(s):  
Iwona Grzeskowiak ◽  
Wtodzimierz Galezowski ◽  
Arnold Jarczewski
Keyword(s):  
Proton Transfer ◽  
Kinetic Study ◽  
Transfer Reaction ◽  
Isotope Effects ◽  
Ion Pairs ◽  
Kinetic Isotope Effects ◽  
Proton Transfer Reaction ◽  
Comparable Amount ◽  
Kinetic Isotope ◽  
Proton Transfer Reactions

The rates of proton transfer reactions between C-acids of the series of nitroalkanes with increasing bulk of R = H, Me, Et, i-Pr substituent as: 4-nitrophenylnitromethane (0), 1-(4-nitrophenyl)-1-nitroethane (1), 1-(4-nitrophenyl)-1-nitropropane (2), 2-methyl-1-(4-nitrophenyl)-1-nitropropane (3) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) have been measured in acetonitrile at pseudo-first-order conditions. The product of the proton transfer reaction with MTBD in acetonitrile is dissociated into free ions while that of the TBD reaction is composed of a comparable amount of ions and ion pairs. The second-order rate constants (k2H) for these bases of almost equal strength in acetonitrile (pKa = 24.70, 24.97 for MTBD and TBD) and C-acids 1, 2, and 3 are: 317, 86, 7.6 dm3 mol–1 s–1; and 15 200, 5300, 1100 dm3 mol–1 s–1, respectively. The appropriate primary deuterium kinetic isotope effects (kH/kD) are 12.5, 10.8, 6.9; and 9.9, 11.2, 12.6. The influence of steric hindrance brought by reacting C-acids and bases is discussed. The different structure of the transition states and the products as mono- and double-hydrogen bonded complexes for these series of C-acids and MTBD and TBD bases is manifested by a distinct reaction mechanism which we attempt to explain.Key words: proton transfer, kinetic study, C-acids, organic bases, acetonitrile, kinetic isotope effects.

Photophysics of Ochratoxin A in Aqueous Solution

2008 ◽  
Vol 63 (11) ◽  
pp. 1321-1326 ◽  
Author(s):  
Dörte Steinbrück ◽  
Claudia Rasch ◽  
Michael U. Kumke
Keyword(s):  
Aqueous Solution ◽  
Proton Transfer ◽  
Ochratoxin A ◽  
Photophysical Properties ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Back Reaction ◽  
Experimental Conditions ◽  
Fluorescence Measurements ◽  
Proton Transfer Reactions

Abstract The photophysics of Ochratoxin A (OTA) in aqueous solution strongly depends on the pH. Due to its molecular structure OTA is prone to an excited state proton transfer reaction, which rules the photophysical properties. Based on results of absorption and fluorescence measurements the rate constants of the proton transfer reactions (forward and back reaction) were determined and subsequently, the pK*a value was calculated. Based on the results, optimized experimental conditions for the analysis can be determined e. solvent conditions (HPLC chromatography) or excitation and emission wavelength (fluorescence spectroscopy).

O16-Induced Transfer Reactions onfp-Shell Target Nuclei. I. The (O16,N15) One-Proton Transfer Reaction

1973 ◽  
Vol 7 (1) ◽  
pp. 107-121 ◽  
Author(s):  
H. J. Körner ◽  
G. C. Morrison ◽  
L. R. Greenwood ◽  
R. H. Siemssen
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Transfer Reactions

Kinetics of Proton Transfer Reactions of Carbon Acids. IV. Primary Deuterium Isotope Effect in the Reaction of Di-(4-nitrophenyl)methane-d2 with t-Butoxide

1974 ◽  
Vol 52 (4) ◽  
pp. 592-596 ◽  
Author(s):  
Jae-Hang Kim ◽  
Kenneth T. Leffek
Keyword(s):  
Proton Transfer ◽  
Isotope Effect ◽  
Activation Parameters ◽  
Proton Transfer Reaction ◽  
Transfer Reactions ◽  
Deuterium Isotope Effect ◽  
Enthalpy Of Activation ◽  
Proton Transfer Reactions ◽  
Carbon Acids ◽  
Kinetics Of

The primary deuterium isotope effect has been measured for the proton transfer reaction from di-(4-nitrophenyl)methane to t-butoxide ion in a solvent consisting of 10% v/v toluene in t-butanol at a series of temperatures between 20 and 45 °C. The isotopic rate ratio, kH/kD, is 7.3 at 25 °C. The activation parameters showed an enthalpy of activation difference (ΔHD≠ − ΔHH≠) of only ca. [Formula: see text] kcal mol−1 and an entropy isotope effect (ΔSD≠ − ΔSH≠) of −2.4 cal mol−1 deg−1. The latter indicates, according to the theory of Bell, that tunnelling of the proton through the energy barrier is unimportant in this reaction. This result is compared to other reactions in the literature, in which tunnelling has been postulated to occur.

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