scholarly journals Adsorption of Methanol on the MgO(100) Surface:  An Infrared Study at Room Temperature

2004 ◽  
Vol 108 (47) ◽  
pp. 18311-18317 ◽  
Author(s):  
Jennifer Rudberg ◽  
Michelle Foster
1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.


1967 ◽  
Vol 71 (9) ◽  
pp. 2938-2945 ◽  
Author(s):  
Enzo Borello ◽  
Adriano Zecchina ◽  
Claudio Morterra

1995 ◽  
Vol 60 (7) ◽  
pp. 1094-1100 ◽  
Author(s):  
Ivona Malijevská ◽  
Martin Polášek

Spectra of acetic acid solutions in carbon tetrachloride were taken at room temperature over the concentration range 0.025-0.00125 mol dm-3. Solutions of acetic acid were modelled as an ideal mixture of monomers, and cyclic and linear dimers. Regression analysis effected separation of the experimental envelope into its component bands. Band shapes were approximated by a Lorenzian function with the resolved band peak frequencies 1 712 cm-1 for the cyclic dimer, 1 724 cm-1 for the linear dimer and 1 765 cm-1 for the acetic acid monomer. Mean values of equilibrium constants for the standard state of unit concentration are 2 700 for the cyclic and 393 for the linear dimer, respectively.


1996 ◽  
Vol 25 (12) ◽  
pp. 1089-1090 ◽  
Author(s):  
Xue-Zhong Sun ◽  
Ian G. Virrels ◽  
Michael W. George ◽  
Hideo Tomioka

1978 ◽  
Vol 56 (12) ◽  
pp. 1681-1686 ◽  
Author(s):  
Ginette Trudeau ◽  
K. C. Cole ◽  
Rachel Massuda ◽  
C. Sandorfy

It has been shown previously that certain anesthetics hinder the formation of hydrogen bonds of the [Formula: see text] types. An attempt bas now been made to correlate this hydrogen bond 'breaking' property with anesthetic potency. As a measure of the former, relative intensifies of infrared bands related to 'free' and hydrogen bonded species were used. The band which was chosen for this purpose is the OH or NH stretching + in-plane bending combination band. This made it possible to carry out the measurements at room temperature. A semi-quantitative relationship has been found. Its significance for the theories of anesthesia is discussed.


1967 ◽  
Vol 71 (9) ◽  
pp. 2945-2951 ◽  
Author(s):  
Enzo Borello ◽  
Adriano Zecchina ◽  
Claudio Morterra ◽  
Giovanna Ghiotti

2008 ◽  
Vol 62 (10) ◽  
pp. 1124-1128 ◽  
Author(s):  
Andrea Pesapane ◽  
Christopher M. Snively ◽  
Richard M. Ikeda ◽  
D. Bruce Chase ◽  
John F. Rabolt

Planar array infrared (PA-IR) spectroscopy was used to study polyphenylene sulfide (PPS) at room temperature during the application of a sinusoidal elastic deformation. All of the intensity in the dynamic spectra was contained within the in-phase spectrum, which was expected since the measurements were carried out at room temperature, far below the glass transition temperature. The contributions of chain orientation, sample thinning, and stress-induced band shifts were separated in the dynamic spectra. It was found that the effects of chain orientation and sample thinning canceled each other out. Stress-induced band shifts far below the spectral resolution, on the order of 0.01 cm−1, were quantified and used to calculate the stress optical coefficients and mode Gruneisen parameters for PPS.


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