Non-hydrogenous Materials and Carbon

Abstract

In this chapter we consider the analysis of the spectra from nonhydrogenous materials ( §11.1) with chlorine ( §11.1.1) and some minerals ( §11.1.2) as examples. Carbon ( §11.2) in its allotropic forms of diamond ( §11.2.1), graphite ( §11.2.2) and the fullerenes and their derivatives ( §11.2.3) has been studied extensively by INS spectroscopy.In addition to the pure forms of carbon, there are a wide range of carbons of varying crystallinity and hydrogen content that are industrially important. These materials form a continuum from almost pure carbon to those with carbon-hydrogen ratios typical of organic compounds. The materials include amorphous hydrogenated-carbon ( §11.2.4) and a range of industrial carbons ( §11.2.5) such as coal, catalyst supports, catalyst coke and carbon blacks. Finally, metal carbonyl complexes ( §11.2.6) are also considered.While most INS studies exploit the large incoherent cross section of hydrogen to achieve both sensitivity and selectivity, there are a number of non-hydrogenous systems that have been successfully studied. The motivation is generally the same as for hydrogenous systems: the ease of calculation of the INS spectrum and the absence of selection rules so all the modes are observable. The theory is the same as for hydrogenous systems so the intensity is amplitude dependent. Thus modes such as outof-plane bends and torsions give the strongest features and the lattice mode region is readily observed. These are all modes that are often difficult to observe by infrared and Raman spectroscopy.The major difficulty with studying non-hydrogenous compounds is lack of sensitivity. This largely accounts for why there are few studies of