Fine structure disregard

As an example, consider an unknown substance that has the molecular formula C15H12. A comparison of its spectrum (Fig. 7.21) with that of anthracene (Fig. 7.19) shows that the two speetra are nearly identical. Disregarding minor bathochromic shifts, the same general peak shape and fine structure appear in the spectra of both the unknown and anthracene, the model compoimd. You may then conclude that the unknown is a substituted anthracene derivative. Further structure determination reveals that the unknown is 9-methylanthracene. The spectra of model compounds can be obtained from published catalogues of ultraviolet spectra. In cases in which a suitable model compound is not available, a model compound can be synthesized and its spectrum determined. 

V, the central part of the quark-antiquark potential, is flavour-independent. It may be supplemented by spin-spin, spin-orbit, or tensor components to describe the fine or hyperfine structure of the multiplets, but we shall disregard these corrections here. 

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