Selection Rules for Singlet‐Triplet Perturbations in Polyatomic Molecules

1949 ◽  
Vol 17 (7) ◽  
pp. 665-666 ◽  
Author(s):  
Donald S. McClure

C. V. Raman was born on 7 November 1888. A 100th anniversary • is a milepost, an occasion on which to review the best known of his contributions to science: the recognition that light scattered from a transparent medium includes wavelengths shifted from that of the incident radiation. It was realized from the outset that these shifts were due to an interaction, subtly different from the ordinary processes of absorption and emission, involving exchange of energy between radiation and the molecules of the medium. The discovery was promptly christened the Raman effect by Pringsheim (1), a phrase that caught on immediately and survives today. Its announcement in 1928 drew the attention of scientists around the world and ushered in a period of rapid development that brought the new spectroscopy onto a plateau where it remained, with few changes of substance, for practically a quarter of a century. For most purposes the experimental procedures were easily adapted from tried and true methods already in place for measurement of fluorescence: such instruments were put together from basic building blocks and examples already existed in a number of laboratories. The necessary theory, including selection rules and related symmetry considerations, emerged more gradually and several years elapsed before their framework was firmly in place. To some extent, however, this delay could be attributed to the greater attention now given to polyatomic molecules whose spectra had not been seriously addressed in the older forms of spectroscopy.


2000 ◽  
Vol 98 (21) ◽  
pp. 1763-1770 ◽  
Author(s):  
Vincenzo Aquilanti, Andrea Beddoni, Simonett

Sign in / Sign up

Export Citation Format

Share Document