Abstract

Neat cyclopentanone (CYP), when cooled to ⩽4.2 K and irradiated with ultra­violet light, exhibits a sharp zero-field optically detected magnetic resonance (zf-ODMR) spectrum. Three transitions were initially found [1,2]; however, Shain and Sharnoff [3] subsequently detected six additional resonances (two "satellite" triads) of much lower intensity separated from the "normal" triad by 9-214 MHz. A double resonance experiment using two microwave fields to excite transitions in different triads seemed to indicate some communication between them. For this reason, it was suggested that different electronic and/or nuclear configurations of the isolated molecule are responsible for the different triads, and that these communicate via a rapid exchange process, perhaps enhanced by tunneling. But later CW and pulsed ODMR experiments [4] failed to reveal the existence of such a process, thus casting doubt on this interpretation.

© 1984 Optical Society of America