INVESTIGATION OF OPTICALLY GENERATED TRANSIENT ELECTRONIC DEFECTS ANDPROTONIC TRANSPORT IN HYDROGEN-BONDED MOLECULAR-SOLIDS - ISOMORPHS OFPOTASSIUM DIHYDROGEN PHOSPHATE

Recent results are reported from our study of a new class of transient electronic defects generated with ultraviolet (UV) photons in hydroge n-bonded molecular solids represented by isomorphs of dihydrogen phosp hate. At room temperature, the defect forms 1.6 +/- 0.4 ps after UV tw o-photon excitation, decays nonexponentially in almost-equal-to 20 s, and absorbs from the UV to the near-IR. The defect is identified as a HPO4- radical and supports proposed formation and decay mechanisms bas ed on protonic transport. These findings also call into question inter pretations of ionizing radiation results.