Chapter 6. Spectra of X–H Systems (with Emphasis on O–H and N–H Groups)

Summary

Chapter 6 completes the discussion of the group frequencies associated with the hydrocarbon frameworks of organic molecules by surveying those frequencies identified in aromatic (arene) ring systems. The chapter deals primarily with the benzene ring and its derivatives. However, the extension of these arguments to aromatic ring systems in general is established. A distinct difference between aromatic and aliphatic spectra is pointed out. There is a significant amount of information contained in the vibrational spectra that can be applied to establish the substitution pattern of these rings. The chapter contains two examples where the application of the aromatic group frequencies establishes the molecular structure including the substitution pattern.

Chapter 6 is followed by the first of three exercise sections.

The Introduction to the Exercises explains how the exercises are organized and also includes information about individual exercises.

Exercise Section I contains four exercises, first and most importantly, in Exercises 1–3 the reader is immersed in the interpretation of ten pairs of infrared and Raman spectra, all of which are hydrocarbons. Secondly, it requires that the reader review in particular detail the discussions of Chapter 2 that involve strategies employed in the interpretation of the spectra. This first set of exercises signal that this is a point where the reader is asked to go back and review not just the protocol of interpretation but all of the details of the material discussed in chapters 2–6.