Charles S. Williams

Bio: Charles S. Williams is an academic researcher. The author has contributed to research in topics: Halide & Pyridine. The author has an hindex of 1, co-authored 1 publications receiving 721 citations.

The Chemistry of Complexes Containing 2,2′-Bipyridyl, 1, 10-Phenanthroline, or 2,2′,6′,2”-Terpyridyl as Ligands

Abstract: Publisher Summary In this chapter, one attempts to present a review giving emphasis to these new fields, and to this end as much material as possible has been subdivided under the headings of the various techniques and types of information. As a result of the chosen subdivision, certain aspects, such as the nature of the metal-to-ligand bonding are discussed in more than one section. Little mention will be made of the analytical uses of these ligands, which have recently been reviewed separately (711), of the synthesis of ring-substituted derivatives of the parent ligands, although a potentially useful method using transition-metal complexes has been reported; or of related species, such as 4,4‘-bipyridyl. The coverage of the literature is complete up to the end of 1967, and usually to the end of April 1968, and although many publications have regretfully not been mentioned, one have attempted to discuss the great majority of those papers which one believe to be of special importance.

Size-dependence of the enhanced Raman scattering of pyridine adsorbed on Agn (n = 2-8, 20) clusters

Abstract: We present a time-dependent density functional theory (TDDFT) study of the size-dependence of the absorption and Raman scattering properties of pyridine interacting with small silver nanoclusters Agn (n = 2−8, 20). By employing a recently developed short-time approximation for the Raman scattering cross section we simulate both the normal and the “surface”-enhanced Raman spectra. The absorption spectra of the small silver clusters are studied both in the gas phase and embedded in rare gas matrices. We find that both the absorption and Raman properties depend strongly on cluster size and adsorption site. The normal Raman spectra of Agn−pyridine complexes resemble that of isolated pyridine, with enhancements which increase as cluster size increases. In contrast to this, both the enhancement and the appearance of the “surface”-enhanced Raman spectrum show a very strong dependence on cluster size. The total enhancements for the complexes are between 103 and 104 and quite surprisingly the strongest enhancement...