Intensities Of IR Absorption Bands Research Articles

ChemInform Abstract: An ab initio “3.1” Quantum Chemical Investigation and LMO Interpretation of the Integrated Intensities of IR Absorption Bands in NH3, PH3, NF3, and PF3

ChemInform Abstract: An ab initio “3.1” Quantum Chemical Investigation and LMO Interpretation of the Integrated Intensities of IR Absorption Bands in NH3, PH3, NF3, and PF3

Study of the structure of butadiene-styrene copolymers by IR spectroscopy

A study is made of temperature dependences of the intensity of IR absorption bands of block and statistical butadiene-styrene copolymers and PS. Five relaxation transitions are observed in the temperature range of 25–150°. Special features of these transitions are discussed. The presence of high-temperature relaxation transitions of the same type for block-and statistical butadiene-styrene copolymers proves similar structural heterogeneity.

IR spectra and structure of poly(p-phenylene) - a theoretical study

The frequencies and the intensities of IR absorption bands are calculated for poly(p-phenylene) (PPP) transferring the parameters from toluene, and they are found to correspond well to the experimental ones. Hence significant effects of electron delocalization and electron-phonon coupling are absent in (the IR spectrum of) PPP, in contrast to polyacetylene; the electronic structure of PPP is similar to that of the monomer. Symmetry considerations are utilized to discuss effects of possible nonplanarity of PPP and of orientation.

Effect of Medium on the Intensity of Infrared Absorption Bands

The paper presents an extensive study of the solvent effect upon the intensity of ir absorption bands. Because of the special importance of the (X—H) bonds =C, O, H), this study is restricted to the (N—H) and the (O—H) bonds of diphenylamine and α-naphthol, respectively. An easy way to calculate the integrated intensity directly from the record chart, saving much time and effort and avoiding a source of appreciable error, has been developed. The determination of the intensity in the gas phase ( Ag) is difficult. An extrapolation method for determining ( Ag) is presented. The values found are: [Formula: see text] It is also found that the absolute solvent interactions play an important role in the intensity variation.

Studies on Reaction of Poly (vinyl alcohol) with 2-Substituted 4-Amino-6-chloro-1, 3, 5-triazines

In order to clarify the mechanism of the reaction of hydrophilic fiber with reactive dyes, the studies were carried out on the system of poly (vinyl alcohol) (PVA) and 2-substituted 4- amino-6-chloro-1, 3, 5-triazine as the model reaction. The reaction proceeded in dimethyl sulfoxide solution in the presence of sodium hydroxide aqueous solution. The reaction rate was determined by the ratio of the intensity of IR absorption band at 805 cm-1 to that at 2900 cm-1. It was found that the empirical reaction was of the first order and its rate was proportional to the concentrations of PVA, reactant and NaOH in the dilute solution, respectively, but the initial reaction rate decreased with increasing concentration of NaOH. Assuming the second order nucleophilic substitution, it was found that the relation between the reaction rate constant and the substitution constant in triazine derivatives obeyed the Hammett's rule approximately and Q=+2.8. The rate of initial reaction between PVA and the compounds having a substituent on p-position of benzene ring of 2-anilino 4-amino-6-chloro-1, 3, 5-triazine was found to be the following order, p-NO2 p-Cl H p-CE3. It was also clarified that the effect of substituent of -s- triazine ring on the rate of the reaction of PVA with cyanuric chloride derivatives was dependent on its electron density.