Vibrational spectra of highly oriented polyacetylene.

Infrared spectra of highly oriented polyacetylenes have been recorded and analysed in terms of their polarization properties. Polarized infrared data for the iodine doped polymer are also reported and discussed.     

Hydration, charge, size, and shape characteristics of peptides from their CZE analyses

A CZE model is presented for peptide characterization on the basis of well-established physicochemical equations. The effective mobility is used as basic data in the model to estimate relevant peptide properties such as, for instance, hydration, net and total electrical charge numbers, hydrodynamic size and shape, particle average orientation, and pH-microenvironment from the charge regulation phenomenon. Therefore 102 experimental effective mobilities of different peptides are studied and discussed in relation to previous work. An equation for the estimation of peptide hydration as a function of ionizing, polar, and non-polar amino acid residues is included in the model. It is also shown that the shape-orientation factor of peptides may be either lower or higher than one, and its value depends on a complex interplay among total charge number, molar mass, hydration, and amino acid sequence.     

Vibrational spectra of polyacetylenes

A considerable amount of information about optical and electronic properties of polyacetylenes has been obtained during the last decade from vibrational spectroscopy. In this lecture several basic points not yet fully understood will be discussed and a new method for evaluating the vibrational density of states for random defects will be presented.     

Infrared anisotropy of highly oriented CIS-rich polyacetylenes

Polarized infrared spectra of highly oriented (a = 7) polyacetylenes prepared using a new catalyst exhibit a regular pattern of interference fringes.The observed birefringence of the samples is consistent with a strong anisotropy of the refraction index (n6/n = 1.9). Our data are interpreted within the framework of the tight binding theory for the electronic states proposed by Cojan et al.     

A study of the conformational analysis and intermolecular hydrogen-bonding in solid malonaldehyde by infrared spectra

The low-temperature infrared spectrum of solid malonaldehyde (MA) is analyzed and discussed. It is shown that the open chain s-trans conformation is stabilized by the formation of a strong intermolecular H-bond.