CRYSTALLOGRAPHY OF MOLECULAR EXCITED-STATES - TRANSITION-METAL NITROSYL COMPLEXES AND THE STUDY OF TRANSIENT SPECIES

The study of photoinduced processes in crystals is a frontier area of crystallographic research, which requires development of novel experim ental and computational methods, In a series of studies, long-lived me tastable states, generated upon photoirradiation of transition-metal n itrosyl complexes, have been identified as eta(2) nitrosyl and isonitr osyl linkage isomers, and their detailed geometry has been determined, Calculations using density functional theory indicate that the specie s correspond to minima on the ground-state potential energy surface, T he time-structure of synchrotron sources opens the possibility of time -resolved studies of transient species in crystals at the atomic level , Possible strategies for such experiments are described.