The purchase of a versatile picosecond optical pulse system consisting of generation, characterization, and transduction components is proposed. No such system exists in the University of North Carolina at this time. The system will be used as a tool to create excited states of moieties in chemical, biochemical, and biological systems. Determination of rise and fall times of photoexcited transient intermediates in the 10 ps to 10 ns time range will be the primary measurement. Direct emission from excited states will be used but the proposed system is far more versatile. It will enable measurement of characteristic times and mechanisms of change for non-emissive states by transient absorption techniques. The observed characteristic times are very sensitive to neighboring environments and will be used to measure energy transfer and electron transfer between donors and acceptors employed as markers in studies of structure and dynamics operative in biochemical and biological systems and will be used in the creative development of systems designed for energy conversion and unsaturated organometallic complexes useful in organic synthesis. The versatility of the system obtained by excitation and probe capabilities over broadly tunable ranges in the visible and near UV will be used in well developed ways to conduct new experiments concerned with: photoenergy conversion in polymers and artificial photosynthesis; characterization of biological macromolecules and studies of the motions of phages and other systems in which the molecules occur; characterization of macromolecules contained in and derived from invertebrate animals; the synthetic design and mechanistic characterization of molecules intended as high energy unsaturated organometallics. The system will be accessible to users throughout the university when not in the service of the primary groups. Extension of existing nanosecond capabilities of measurement, data acquisition, and data reduction to picosecond times is necessary for future innovative development by the primary user groups. The extension will significantly draw on resources established for studies in the nanosecond time range.
