Electron delocalization and relative stabilities for the favored and rare tautomers of hydroxyazines in the gas phase – A comparison with aminoazines

2014 ◽  
Vol 1042 ◽  
pp. 8-15 ◽  
Author(s):  
Ewa D. Raczyńska
Keyword(s):  
Gas Phase ◽  
Electron Delocalization ◽  
Relative Stabilities ◽  
Rare Tautomers

Rapid Evaluation of Suitable Substrates with High Affinity to Artificial Caffeine Receptors by MS Based Techniques

2005 ◽  
Vol 60 (10) ◽  
pp. 1077-1082 ◽  
Author(s):  
Daniela Mirk ◽  
Heinrich Luftmann ◽  
Siegfried R. Waldvogel
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Collision Induced Dissociation ◽  
Rapid Evaluation ◽  
Tandem Mass ◽  
Binding Affinities ◽  
Electrospray Tandem Mass Spectrometry ◽  
Relative Stabilities ◽  
Receptor Complexes ◽  
High Affinity

A modification of our triphenylene ketal based receptor facilitates electrospray tandem mass spectrometry investigations. Binding affinities of eleven potential substrates, e.g. caffeine and other xanthine alkaloids, are probed in the gas phase with collision induced dissociation. The relative stabilities of the substrate-receptor complexes are rapidly determined and the findings are correlated with the corresponding results in solution.

AbInitio SCF MO calculations on the reaction of hydroxyl radical with cytosine

1986 ◽  
Vol 64 (5) ◽  
pp. 914-919 ◽  
Author(s):  
Beverley G. Eatock ◽  
William L. Waltz ◽  
Paul G. Mezey
Keyword(s):  
Hydroxyl Radical ◽  
Radiation Damage ◽  
Gas Phase ◽  
Solvent Effects ◽  
Oh Radical ◽  
Mo Calculations ◽  
Relative Stabilities ◽  
Ring Atom ◽  
Living Tissues ◽  
Abinitio Calculations

Abinitio calculations have been carried out on the relative stabilities of various possible products of the reaction between cytosine and the OH radical. These products are of importance in modelling radiation damage to living tissues. The preferred theoretical gas-phase addition site is the C6 ring atom according to these calculations. The analysis of a series of possible contributions to solvent effects strongly suggests the predominance of intermolecular H bonds in stabilizing the experimentally observed C5 adduct.

Effects of side chains in gas-phase amino acids: Conformational analysis and relative stabilities

2009 ◽  
Vol 901 (1-3) ◽  
pp. 81-87 ◽  
Author(s):  
Gang Yang ◽  
Lijun Zhou ◽  
Yuangang Zu ◽  
Yujie Fu ◽  
Rongxiu Zhu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Conformational Analysis ◽  
Gas Phase ◽  
Side Chains ◽  
Relative Stabilities

Ab Initio Theoretical Studies of Relative Stabilities and IR Spectrum of 5-Methylcytosine Tautomers

2003 ◽  
Vol 2003 (4) ◽  
pp. 195-199 ◽  
Author(s):  
Lida Ghassemzadeh ◽  
Majid Monajjemi ◽  
Karim Zare
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Relative Energy ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Relative Stabilities ◽  
B3lyp Method ◽  
Wide Range ◽  
Good Agreement

The structure and relative energies of the tautomers of 5-methylcytosine in the gasphase and in different solvents are predicted using MP2 and density functional theory methods. The order of stability for these tautomers is C3>C1>C2>C4>C5>C6 calculated by MP2 and C1>C3>C2>C4>C5>C6 calculated by the B3LYP method. Relative energy calculations are performed in wide range of solvent dielectrics and in all solvents the oxo-amino C1 is predicted as the most stable tautomer. The infrared spectra of two dominant tautomers are calculated in the gas phase using HF and density functional theory. Good agreement between calculated (DFT) and experimental harmonic vibrational frequencies is found.

Relative stabilities of tetramethyl orthosilicate and tetraethyl orthosilicate in the gas phase

1991 ◽  
Vol 12 (3) ◽  
pp. 179-184 ◽  
Author(s):  
Jason C.S. Chu ◽  
James Breslin ◽  
N.S. Wang ◽  
M.C. Lin
Keyword(s):  
Gas Phase ◽  
Tetraethyl Orthosilicate ◽  
Relative Stabilities

Computational study of relative stabilities of C60(Ih) and C70(D5h) gas-phase clusters

1988 ◽  
Vol 125 ◽  
pp. 155-162 ◽  
Author(s):  
Jerzy M. Runziński ◽  
Zdeněk Slanina ◽  
Masatomo Togasi ◽  
Eiji Ōsawa ◽  
Takeshi Iizuka
Keyword(s):  
Gas Phase ◽  
Computational Study ◽  
Relative Stabilities ◽  
Gas Phase Clusters

Abinitio SCF MO calculations on the reactions of OH radical with pyridine and pyridinium ion

1982 ◽  
Vol 60 (7) ◽  
pp. 813-819 ◽  
Author(s):  
M. C. Anthony ◽  
W. L. Waltz ◽  
P. G. Mezey
Keyword(s):  
Hydroxyl Radical ◽  
Experimental Information ◽  
Electron Delocalization ◽  
Oh Radical ◽  
Reaction Paths ◽  
Mo Calculations ◽  
Relative Stabilities ◽  
Electrophilic Character ◽  
Determining Factor ◽  
Pyridinium Ion

Relative energies of various products formed in the reaction of pyridine and pyridinium ion with the hydroxyl radical are calculated using non-empirical SCF MO techniques. The favourable electron delocalization in the meta-products, rather than the electrophilic character of the OH radical is the determining factor of relative stabilities. Calculated energy barriers along approximate reaction paths correlate with the available experimental information.

Sign in / Sign up

Export Citation Format

Share Document