Synthesis and applications of large heterometallic cluster systems

Work has proceeded according to schedule on all research topics. Uniquely well defined clusters of gold are now available for optical measurements. A comprehensive experimental investigation has been carried out to determine the non-linearity of these samples on a femtosecond timescale. These results are presented and prove that: the nonlinear refractive index rises and relaxes on a sub-picosecond timescale; the nonlinearity is predominant positive imaginary originating from a hot electron contribution; and the nonlinearity is independent of the size of the particle.