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Infrared and Raman spectroscopic characterization of the hydrogen-bonding netwo...
Jarmelo, S.; Reva, I.; Carey, P. R.; Fausto, R.The IR spectra (4000-400Â cm-1) of neat and isotopically substituted (ND/ODÂ <=Â 10% D and [congruent with]30% D) polycrystalline l-serine ([alpha]-amino-[beta]-hydroxypropionic acid; HO-CH2-CH(NH3)+-COO-) were recorded in the temperature range 300-10Â K and assigned. The isotopic-doping/low-temperature methodology, which allows for decoupling of individual proton vibrational modes from the crystal bulk vibrati...
The Raman spectra of serine and 3,3-dideutero-serine in aqueous solution
Jarmelo, S.; Carey, P. R.; Fausto, R.The Raman spectra of serine [[alpha]-amino-[beta]-hydroxypropionic acid; HOCH2CH(NH3)+COO-] and 3,3-dideutero-serine [HOCD2CH(NH3)+COO-] in aqueous solution were studied in the range 4000-300 cm-1. The data obtained for the deuterated compound are novel and provide compelling evidence that previously reported assignments for the undeuterated amino acid should be revised. ; http://www.sciencedirect.com/scienc...
Low-temperature infrared spectra and hydrogen bonding in polycrystalline dl-ser...
Jarmelo, S.; Reva, I.; Rozenberg, M.; Carey, P. R.; Fausto, R.The FT-IR spectra of polycrystalline dl-serine [[alpha]-amino-[beta]-hydroxypropionic acid; HO-CH2-CH(NH3)+-COO-] and isotopically substituted [ND/ODAlcohol (<10% and >90% D); CD2 (>98% D)] dl-serine were recorded in the range 4000-500Â cm-1 in the temperature range 300-10Â K, and fully assigned. The isotopic-doping/low-temperature methodology, which allows for decoupling of individual proton vibrational modes ...
Preferred Conformers and Photochemical (λ > 200 nm) Reactivity of Serine and 3,...
Jarmelo, S.; Lapinski, L.; Nowak, M. J.; Carey, P. R.; Fausto, R.A systematic investigation of the conformational potential energy surface of neutral serine [HOCH2CHNH2COOH] and 3,3-dideutero-serine [HOCD2CHNH2COOH] was undertaken, revealing the existence of 61 different minima. The structures and vibrational spectra of the most stable conformers, which were estimated to have relative energies within 7 kJ mol-1 and account for ca. 93% of the total conformational population a...
Cα−H Bond-Stretching Frequency in Alcohols as a Probe of Hydrogen-Bonding Stren...
Jarmelo, S.; Maiti, N.; Anderson, V.; Carey, P. R.; Fausto, R.The sensitivity of the νCα-H/D vibrational stretching frequency to hydrogen bonding in alcohols is examined by infrared and Raman spectroscopy, supported by DFT(B3LYP)/6-311++G(d,p) calculations. The model compound studied is (R,S)-n-[1-D]propanol. It is shown that the νCα-H/D mode can be successfully correlated with the hydrogen-bond strength in a given solvent, provided the O−H group involved in the hydrogen ...
Cα−H Bond-Stretching Frequency in Alcohols as a Probe of Hydrogen-Bonding Stren...
Jarmelo, S.; Maiti, N.; Anderson, V.; Carey, P. R.; Fausto, R.The sensitivity of the νCα-H/D vibrational stretching frequency to hydrogen bonding in alcohols is examined by infrared and Raman spectroscopy, supported by DFT(B3LYP)/6-311++G(d,p) calculations. The model compound studied is (R,S)-n-[1-D]propanol. It is shown that the νCα-H/D mode can be successfully correlated with the hydrogen-bond strength in a given solvent, provided the O−H group involved in the hydrogen ...
FTIR studies of hydrogen bonding between α,β-unsaturated esters and alcohols
Tonge, P.J.; Fausto, R.; Carey, P.R.The enthalpy (and entropy) of hydrogen bond formation has been measured between the ester carbonyl groups of the two α,β-unsaturated esters thienylacryloyl (TAOMe) and 5-methylthienylacryloyl (5MeTAOMe) methyl ester and the hydrogen bond donors ethanol, phenol and 3,5-dichlorophenol in CCl4. For the esters, the hydrogen bonding strengths were measured by quantitating the amount of bound and unbound donor, using...
Rotational Isomerism in CH3CH2-C(=S)SR (R = CH3, CH2CH3): A Combined Vibrational
Fausto, R.; Martins, A. Gabriela; Teixeira-Dias, J. J. C.; Tonge, P. J.; Carey, P. R.The vibrational and conformational properties exhibited by CHsCH2C(=S)SCHs and CH~CH~C(=S)SCHZCH3 were studied by Raman and infrared spectroscopies for the liquid and solid phases, and by ab initio calculations for the isolated molecule. It is shown that these molecules tend to adopt nonsymmetricconformations near the C(=S)S group, in contrast to their oxygen analogues whose most stable conformers correspond to...
Elucidation of the conformational properties of N-formylglycine dithio acid by ...
Fausto, R.; Teixeira-Dias, J. J. C.; Carey, P. R.Ab initio SCF-MO calculations were carried out for the molecule N-formylglycine dithio acid using STO-3G and 3-21G basis sets. Structures and energies of several conformations of this molecule determined by gradient geometry refinement are reported, and some conformationally dependent local geometry trends discussed. For conformations involving rotational isomerism about the NH-CH2 and CH,-C(=S) single bonds, t...
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