Infrared spectroscopy intermolecular

Frohlich, H. Using Infrared Spectroscopy Measurements to Study Intermolecular Hydrogen Bonding, /. Chem. Educ. 1993, 70, A3-A6. 

Bimodal intermolecular proton transfer in water photoacid-base pairs studied with ultrafast infrared spectroscopy... 

The acid, base, and neutral Lewis base fractions consist of polar molecules capable of hydrogen bonding and, therefore, of intermolecular association. These polar fractions, which constitute nearly two-thirds of the 675°C+ residuum, have high concentrations of heteroelements in comparison to the nonpolar aromatic and saturate hydrocarbons, as shown in Table IX for the residuum from a Russian crude oil. Infrared spectroscopy of the acid fraction revealed mostly pyrroles with phenols but only traces of... 

Since infrared spectroscopy also provides information about physical structure, infrared imaging can be used to determine spatial distribution of physical properties as well. Some of the properties include intermolecular and intramolecular order, hydrogen bonding, protein secondary structure, complexation and functional group orientation. 

Infrared Spectroscopy. There are four principal contributions from IR measurements (1) they show the presence of H bonded N—H groups (2) they distinguish between intra- and intermolecular H bonds in solution (3) they help establish the trans configuration of the... 

Proton magnetic resonance, infrared spectroscopy and dielectric relaxation measurements, on ortho- and meta-disubstituted anilines, indicate that (despite what is expected on the basis of the usual steric hindrance arguments) a meta-substituted compound such as 32 results in more hindered rotation of the NH2 group than for orf/zo-substituted compounds such as 33. Solute/solvent and solute/solute intermolecular hydrogen bonding interactions are responsible for this hindered rotation73. 

One should remember that the atoms and molecules in liquids are not motionless but in a state of flux determined by the intermolecular interactions and temperature. From the study of microwave spectroscopy discussed in chapter 4, it was found that rotational diffusion processes in liquids are characterized by relaxation times the order of a few picoseconds. When a liquid is irradiated with UV or visible radiation which involves frequencies greater than 10 Hz, the atoms and molecules appear to be motionless because the frequency of the electromagnetic radiation is much greater than that associated with molecular motion (10 Hz and lower). The same is true for infrared spectroscopy except in the... 

Infrared spectroscopy is based on the conversion of IR radiation into molecular vibrations. For a vibration to be IR-active, it must involve a changing molecular dipole (asymmetric mode). For example, vibration of a dipolar carbonyl group is detectable by IR spectroscopy. Whereas IR has been traditionally used as an aid in structure elucidation, vibrational changes also serve as probes of intermolecular interactions in solid materials. 

Rini, M., Mohammed, O. F., Magnes, B.-Z., Pines, E., Nibbering, E. T. J, Bimodal intermolecular proton transfer in water photoacid-base pairs studied with ultrafast infrared spectroscopy, in Ultrafast Molecular Events in Chemistry and Biology , J. T. Hynes, M. Martin (Eds.), Elsevier, Amsterdam, 2004,... 

Infrared spectroscopy of condensed media under pressure is usually used to investigate the variation of the vibrational properties, which are a direct measure of the interatomic (intermolecular) restoring forces acting on the atoms, and thus of the effective interatomic interactions which are brought about by the electronic and ionic contributions. Ideally, the calculation of the vibrational properties of a solid should follow ab initio calculations of its pressure-temperature stability, of its equation of state, and of its electronic properties. This ideal is very seldom achieved, even for the k = 0 modes in the centre of the Brillouin zone which can be probed by optical measurements in the i.r. 

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