J. V. Quagliano

Bio: J. V. Quagliano is an academic researcher. The author has contributed to research in topics: Infrared spectroscopy & Infrared. The author has an hindex of 19, co-authored 23 publications receiving 1431 citations.

The Infrared Spectra of Adsorbed Molecules

Abstract: Publisher Summary This chapter describes the chemisorption on supported-metal samples, chemisorption on acidic oxides, spectra of adsorbed water and surface hydroxyl groups on nonacidic oxides, infrared spectra of physically adsorbed molecules, the pressed-salt method for obtaining spectra of adsorbed molecules, and spectra of molecules adsorbed on unsupported metals. Not only is the infrared method applicable to studies of both chemisorptions and physical adsorption systems, but it also provides a means of distinguishing between chemisorption and physical adsorption. The infrared spectra of physically adsorbed molecules are similar to the spectra of the gaseous, liquid, or dissolved states. While, minor differences in band positions may be observed during physical adsorption, these differences are of the same magnitude as the differences between the various unadsorbed states. No new bands are observed in the spectra of physically adsorbed molecules which cannot be attributed to vibrations, which provide infrared or Raman bands in the liquid state.

Complex formation between metallic cations and proteins, peptides and amino acids.

Abstract: Publisher Summary The chapter discusses the complex formation between metallic cations and proteins, peptides, and amino acids. The chemistry of complex formation describes that the nature of metal-protein complexes must vary widely with the nature of the metal, and that the proteins with their many reactive side chains have the potential capacity to bind most metals very tightly. Apart from the alkali metals, it is safe to assume that any metallic cation that finds its way into a living organism will spend an important part of its time bound to proteins before it is excreted or laid down in skeletal tissue. The chapter explores those complexes, in which the bound metal is in equilibrium with clearly defined metal ions or simple complexes in solution. The equilibrium dialysis technique has proved to be particularly useful. Chrome tanning of animal hides is the most widespread practical application of complex formation between metal and protein. The chapter presents a survey of what has been gained from the experimental studies of complex formation between proteins and metal ions in a series of reversible systems. The chapter also discusses the effect of metal ions on the stability of proteins, and their interactions with other molecules. The solubility of proteins may be pictured as determined by a balance between attractive and repulsive forces, involving, on one hand, the interaction of the protein molecules with the solvent and, on the other hand, the interaction of the protein molecules with one another. The balance of these forces determines the degree to which the protein molecules tend to disperse and surround themselves with the medium and the degree to which they tend to aggregate together and surround themselves with other protein molecules.