Our main activities are

• Research: The goal of our research is to discover new and better ways to control and optimize photoinduced processes in organic and biological materials.  Our research involves both the synthesis of new materials and the use of laser spectroscopy and microscopy to study dynamics.  This work has practical applications ranging from solar energy conversion to photoprotection against skin cancer.

• Education: Since 2000, we've graduated 8 Ph.D., 3 M.S., 18 B.S. students, and continued in the training of 6 post-docs. Our people get great jobs in both academics and industry-read more about them here.

• Outreach: In collaboration with Professor Greg Beran and a group of motivated UCR undergrads, we have developed a program that brings chemistry demonstrations to RUSD schools. We've tailored the program to meet the California State Science Requirements for States of Matter, The Water Cycle, and Electricity & Magnetism.

Photomechanical Molecular
Crystal Nanowires

  A novel anthracene-9-(1,3-butadiene) derivative, dimethyl-2(3-(anthracen-9-yl)allylidene)malonate (DMAAM) has been synthesized.  We have studied its solid-state structure and reactivity and show that a pulse of visible light can induce a dramatic curling motion in crystalline nanowires. 

Considerable effort has been devoted to making static coiled nanowires, usually by changing extrinsic factors like the nanowire’s surface chemistry or solvent environment. The coiling observed in this paper is qualitatively different, since it relies on intrinsic chemical changes taking place inside the wire itself, namely the E↔Z photoisomerization.  This motion occurs under uniform illumination conditions and illustrates how a molecular crystal nanostructure can undergo a nontrivial and possibly useful geometry change after photoexcitation.

The photoinduced motion is observed for nanowires composed of either (E)- or (Z)-DMAAM and may involve interactions between crystalline reactant and amorphous product phases.