Uses of Point Group Symmetry

1 As we have seen, the formal definition or optical activity is based upon the absence off an improper axis of rotation. The two definitions are equivalent. 

14 For discussions off chiral organic molecules that do not contain asymmetric carbon atoms, see Wodc. L. C. Jr. Organic Chemistry, Prentice-Hall Englewood Clifts, NJ, 1987 pp 354-356. Schlogl K. Topics Curr. Chem. 1984,125,27. Laarhoven, W. Prinsen, W. J. C Ibid. 1984,125,61 Mcurer. K. P. Vijgllc, F. Ihid. 1985.127. I. 

Point groups for which dipole moments are symmetry allowed or symmetry forbidden 

Symmetry forbidden symmetry element( ) prohibiting dipole) 

The number of vibrational modes of a molecule composed of N atoms is 3N — 6 (or iN — 5 if linear).21 We may find which of these are infrared and Raman active by the application of a few simple symmetry arguments. First, infrared energy is absorbed for certain changes in the vibrational energy levels of a molecule. For a vibration to be infrared active, there must be a change in the dipole moment vector 

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A. The Electronic Transition Dipole and Use of Point Group Symmetry... 

Symmetry Elements and Symmetry Operations 46 Point Groups and Molecular Symmetry 53 Irreducible Representations and Character Tables 59 Uses of Point Group Symmetry 63 Crystallography 74... 

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