ROTATIONAL VIBRATIONAL AND ELECTRONIC SPECTROSCOPY WE have decided to divide this Report into three separate sections on Micro-wave Infrared and Raman and Electronic spectroscopy. The scope has been limited to a consideration of papers listed in Current Chemical Papers for 1967 and thus contains references to work published in the latter part of 1966. Approximately 4000 titles have been scanned and about 900 papers read; no attempt has therefore been made to make the treatment comprehensive. Only papers of special interest to the reviewers or typical of those involved in major advances have been cited. Some slight overlap with the relevant Reports of 19661*2 has been inevitable under the new framework for Annual Reports. Two books devoted to general spectroscopy have appeared recently one by Whiffen3 and the other a set of problems of interest to organic chemists by Baker et aL4 A. D. Walsh Annual Reports 1966,63,44. * D. B. Powell Annual Reports 1966 63 112. D. H. Whiffen ‘Spectroscopy’ Longmans London 1966. A. J. Baker T. Cairms G. Eglinton and F. J. Preston ‘More Spectroscopic Problems in Organic Chemistry’ Heyden London 1967