Spectroscopic and Chemical Evidence for Methylene Singlet-Triplet Intersystem Crossing in Solution

摘要

Singlet-triplet intersystem crossing of methylene in perfluorohexane solution has been investigated by CIDNP. Evidence of this process is shown by the polarized absorption H-NMR signal of C1 3C-CH 2D, a triplet product, which is obtained upon direct irradiation of diazirine in perfluorohexane solution containing saturated deuteriochloroform. These results are confirmed by product analysis as a function of dilution by perfluorohexane. The rate constant for intersystem crossing for singlet methylene to triplet methyllene is evaluated as ca per sec 8xten to the eight power from the data.