Showing papers in "Journal of Molecular Structure in 2002"

TL;DR: Fluorescence emission spectra of serum albumin in the presence of MMI or PTU, recorded at the excitation wavelengths 280 and 295 nm, clearly show that the studied drugs act as quenchers.

TL;DR: The concept of core and valence basins as mentioned in this paper is a topological approach of chemical bonding that enables a position space partition of the electron density in terms of basins of attractor whose chemical significance is given by their location with respect to the nuclei.

TL;DR: In this article, the spectral properties of urea in crystal and in water solution were investigated and it was shown that the series of spectra recorded at various concentrations in water can be decomposed into four basic spectra: the first is the same as the spectrum of liquid water, the second one has features only due H 2 O but is slightly disturbed as compared with the first one and the other two display in addition features due to vibrations in urea.

TL;DR: In this paper, the conformational peculiarities of macromolecules of cellulose of various structural modifications have been studied by the methods of Fourier transform infrared and Raman spectroscopy and theoretical conformational analysis.

TL;DR: FTIR-PAS spectroscopy has the potential to become a non-destructive analysis tool in food safety related research and was used to differentiate and identify microorganisms on a food (apple) surface.

TL;DR: In this paper, the FT-IR and FT-Raman spectra of a sample of acid paper (Paper 3-bleached sulfite softwood pulp) in extreme humid conditions (100% humidity and 100°C) were presented.

TL;DR: In this article, different chemical and spectroscopic techniques have been applied to investigate a peat humic acid (HA) separated by tangential ultrafiltration into different nominal molecular weight (NMW) fractions, each fraction analyzed showed a characteristic DRIFT and NMR pattern.

TL;DR: In this paper, the importance of cooperative interactions and the consequent failure of pairwise models to explain hydrogen-bonding interactions in the solid state and peptides is emphasized. But the results of the calculations have not been discussed.

TL;DR: Weak interactions involving fluorine have been analyzed in the structure of 6-methoxy-1,2-diphenyl with fluorine substitution at para-, meta-, and ortho positions, respectively, on the 1-phenyl ring.

TL;DR: In this paper, the supramolecular hydrogen-bonded molecular networks are formed by the monoanion of squaric acid by itself or in association with the parent acid.

TL;DR: In this article, the synthesis of a novel pyridine containing self-assembling system, L, was reported, which was prepared from the reaction between 2,6-pyridinedicarboxylic acid, [pydc.H2], and 2, 6-pryidinediamine,[pyda], in the presence of Et3N in THF as solvent in 88% yield.

TL;DR: In this paper, the properties of the hydrogen-bonded structures of oxalates are discussed in detail, besides relating their thermal stability to the strength of the networks, showing that the first five amines have different types of hydrogen bonded networks.

TL;DR: In this article, it was shown that cyclodextrins must be flexible not only in solution but also in the solid state, due to weak nonbonded interactions.

TL;DR: In this paper, the results of extended MO calculations using density functional theory (DFT) approximation supported by experimental Raman, 1 H and 13 C NMR studies on thiophene are reported.

TL;DR: The lengths of short strong hydrogen bonds (SSHBs) on enzymes have been determined with high precision (±005 A) from the chemical shifts (δ), and independently from the D/H fractionation factors (φ) of the highly deshielded protons involved as discussed by the authors.

TL;DR: In this article, a 1:1 adduct was observed in an argon matrix using matrix isolation infrared spectroscopy, where acetylene acts as a proton donor to the π cloud of benzene.

TL;DR: In this article, the acceptability of methoxybenzene and its complexes with HF, H 2 O, C 2 H 2, C 2 C 2, H 2 H 4, CH 4 F, CH 3 F and NH 2 CH 3 was investigated using results of DFT calculations at B3LYP/6-311+G ∗ level of theory.

TL;DR: In this paper, the influence of modifying additions of Ce, Zr, La and Cs oxides on the surface electronic states of supported gold have been studied using the methods of IR spectroscopy of adsorbed CO, XRD, XPS, EXAFS and electron microscopy.

TL;DR: In this paper, the proton transfer in the intramolecular hydrogen bond in a series of Schiff bases derivatives of aromatic ortho-hydroxyaldehydes and trans-1,2-diaminocyclohexane has been studied by means of IR, UV-Vis, 1H and 13C NMR spectroscopies.

TL;DR: The results of extended MO calculations using density functional theory (DFT) approximation and multinuclear HR NMR studies on uracil (U) and 5-fluorouracil(5FU) are reported in this article.

TL;DR: The potential use of organic phosphorus acids for the architecture of supramolecular hydrogen-bonded assemblies has been demonstrated by the structural determination of phenylphosphonic acid as discussed by the authors.

TL;DR: In this article, extreme ultraviolet (EUV) spectroscopy was performed on microwave discharges of helium with 2% hydrogen, where lines were identified as hydrogen transitions to electronic energy levels below the ground state corresponding to fractional quantum numbers.

TL;DR: In this paper, the effect of metal on different ligands (benzoic, salicylic, and nicotinic acids) has been compared and linear correlations between changes of the wavenumber of selected bands and the ionic potential as well as electronegativity of cation have been found.

TL;DR: The microwave spectrum of KrAgF has been assigned between 8-18 GHz using a cavity pulsed-jet Fourier transform microwave spectrometer as discussed by the authors, and the structure of the molecule has been calculated from the measured rotational constants of four isotopomers.

TL;DR: Two Schiff's bases of racemic gossypol with amino derivatives of crown ethers were synthesised and studied by FT-IR and 1 H NMR spectroscopy, while their structures were calculated by the PM5 semi-empirical method.

TL;DR: In this article, the EPR signal centred at g = 2.023 has been attributed to CO 3 − radical, which is found to coordinate with occluded water.

TL;DR: In this paper, the pseudo-lattice vibrations characteristic of isolated rings of alumino- and silico-oxygen terahedra were determined using PM3 method.

TL;DR: In this paper, the aggregation of methylene blue (MB), rhodamine 6G (R6G), and rhodamines B (RB) in liquid crystalline solution (anisotropic host) was studied using polarised spectroscopy and in a guest-host system.

TL;DR: In this paper, the polarized IR spectra of 2-hydroxybenzothiazole (HBT) and 2-mercaptobenzothiazoles (MBT) were analyzed using X-ray diffraction.

TL;DR: In this article, X-ray, 13 C NMR and IR data were used to characterize the hydrogen bonds of betaine-acid complexes with different acids and showed that the resulting hydrogen bonds indicate conditions and possible inversion mechanisms of the bonding proton positions.