1,721,062 research outputs found
The influence of back-biting interaction oil the polymerization of conjugated dienes in the presence of Ziegler-Natta catalysts
No full textConformational behavior and magnetic properties of a nitroxide amino acid derivative in vacuo and in aqueous solution
No full textThe conformational behavior and magnetic properties of the R-acetylamino, N′-methylamide derivative of
TOAC(4-amino-2,2,6.6-tetramethylpiperidine-1-oxyl-4-carboxylic acid) have been investigated in vacuo and
in aqueous solution by an integrated computational approach including density functional, post-Hartree
Fock, and continuum solvent models. According to our computations, piperidine rings with an equatorial
placement of the nitroxide moiety are more stable by about 1 kcal/mol than their axial counterparts both in
vacuo and in aqueous solution. With respect to natural residues, TOAC shows a marked preference for helical
conformers, which is further enhanced by polar solvents. A comparison with other CR-tetrasubstituted residues
points out the difference between cyclic and open-chain substituents. The nitrogen isotropic hyperfine coupling
constants (AN) of folded TOAC conformers are similar to those of other nitroxides involving six-membered
rings and are well reproduced by a composite QM/QM/PCM model. The AN values of extended TOAC
conformers are significantly lower because of the constrained nearly planar structure of the piperidine ring
Interplay of electronic, environmental, and vibrational effects in determining the magnetic properties of organic free radicals
No full text
Interplay between “Neutral” and “Charge-Transfer” Excimers Rules the Excited State Decay in Adenine-Rich Polynucleotides
No full textThe excited states of adenine and thymine nucleoside and nucleotide in aqueous solution: a comparative study by time-dependent DFT calculations
No full textAbsorption and Fluorescence Spectra of Uracil in the Gas Phase and in Aqueous Solution: A TD-DFT Quantum Mechanical Study
No full textPCM/TD-DFT study of the two lowest excited states of uracil derivatives in solution: 3 The effect of the functional and of the cavity model
No full textA parameter-free quantum mechanical approach to the calculation of electron transfer rates for large systems in solution
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