12/5 - Faculty Candidate Seminar (materials): Rebekka Klausen, Columbia University
Host: Rob Knowles
Functional Molecules for Catalysis and Electronics
Coupling synthetic chemistry and mechanistic insight is a powerful approach to understanding and enhancing the function of a molecule: this approach unites my graduate and post-doctoral research in asymmetric catalysis and molecular electronics. First, I describe the discovery that the combination of two acids – benzoic acid and a chiral thiourea derivative – catalyzes a highly enantioselective Pictet-Spengler reaction. Yet, identification of a base-promoted rate- and ee-determining step raises fascinating questions about catalyst function and enantioinduction. I use quantitative structure-activity relationships to elucidate this unprecedented catalytic mechanism. Second, I show the design and synthesis of novel organosilicon nanowires. These are highly conductive molecules, with a decay constant rivaling that of conjugated olefins, as shown by incorporation into single molecule circuits. The modular molecular design not only facilitates fine-tuning of the conductance features, but also leads to the proposal of group additivity rules for molecular conductance.