The triplet state of C70. A zero-field study

We report the optical detection in zero field of the three microwave transitions between the triplet sublevels of C70. In n-pentane the bandwidth is 4 MHz (30 MHz in decalin/cyclohexane) and the fine-structure parameters, particularly E, have been found to be site-dependent. The intrinsic population and decay characteristics of the sublevels have been determined. A common decay of the Tz↔Tx and Tz↔Ty transitions has been observed owing to pseudo-rotation within the C70 molecule at 1.2 K.