Ronald E. Erickson

Bio: Ronald E. Erickson is an academic researcher. The author has contributed to research in topics: Infrared spectroscopy & Infrared spectroscopy correlation table. The author has an hindex of 2, co-authored 2 publications receiving 47 citations.

Infrared Spectra of Charge‐Transfer Complexes. VI. Theory

Abstract: The general theory of molecular vibrational transition intensities is discussed with emphasis on electronic reorientation contributions to the intensities. The wavefunctions used by Mulliken to represent the electronic states of donor—acceptor complexes are written to include an explicit dependence on the vibrational coordinates. These functions and the general theory are applied to the intensities of halogen vibrations in donor—acceptor complexes. Specific application to actual complexes requires the estimation of the derivative of the vertical electron affinity of the halogen molecule with respect to its internuclear distance, the electronic transition moment of the charge‐transfer band, the coefficients in the donor—acceptor ground‐state wavefunctions and the difference between the energies of the dative‐ and no‐bond states. Evaluation of each of these parameters is discussed for a number of complexes of halogens and relationships between the wavefunction coefficients and the infrared frequency shifts are described. The calculations indicate that all of the intensity enhancement of the halogen—halogen stretching vibration may be due to electronic reorientation during the vibration. Partly as a result of this conclusion, it is argued that no information about the geometry of the benzene—halogen complexes may be deduced form the infrared spectrum, at least in any simple way. The argument is extended qualitatively to hydrogen‐bonded systems to indicate the probable similarity in explanation for the enhancement of the X—H stretching vibrations. In conclusion, a number of generalizations are presented regarding the spectra of complexes.

Hydrogen Bonding Interaction between Adsorbate Molecules and Surface Hydroxyl Groups on Silica

Abstract: The interactions of the surface hydroxyl groups on amorphous silica with two series of adsorbates, the methylbenzenes and the chloromethanes, have been studied. A correlation is demonstrated between the frequency shifts of the surface hydroxyl stretching vibration and the ionization potential of the adsorbate. A similar correlation is found for the interaction of the hydroxyl group of a carbinol with the methylbenzene series. The importance of charge‐transfer interaction in hydrogen bonding, which is indicated by these correlations, is discussed.

Infrared and Raman Spectra, Force Constants, and the Structures of Some Polyhalide Ions: ICl2−, ICl4−, BrCl2−, and Br3−

Abstract: The infrared and Raman spectra for the polyhalide ions (ICl2−, ICl4−, BrCl2−, and Br3−) are presented. From these data, the X—Y stretching force constant fr, the interaction force constants frr between bond stretching coordinates at 180° to each other, and the interaction force constant frr′ for bond stretching coordinates at an angle of 90° (for ICl4−) have been calculated. The values of fr for the trihalide ions are roughly one‐half the values for the free halogens, and the values of the interaction force constants frr are very large (approximately 35% the value of the stretching constant fr). These rather unusual force constants have been interpreted in terms of the description of the bonding in these ions using p orbitals, which was first suggested by Pimentel. In fact, these results offer rather strong support for the recent evidence from nuclear quadrupole coupling constant measurements of Cornwell and Yamasaki favoring this structure. Attention is drawn to the qualitative similarity between these f...