Lecture Wybren Jan Buma
|21 September 2012||FWN-Building 5115.0017, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Prof. Dr. Wybren Jan Buma|
|Affiliation:||UvA, Van 't Hoff Institute for Molecular Sciences|
|Title:||The difference between left and right|
|Date:||Fri Sep 21, 2012|
|Host:||Thomas La Cour Jansen|
|Telephone:||+31 50 363 4957|
proven to be powerful means to unravel the stereochemistry and conformational heterogeneity of chiral molecules. Their practical applicability, however, is often impeded by small signal intensities. Strategies that would enhance VOA signals and thereby improve the ability of accurately differentiating between optical isomers by means of their vibrational signatures could therefore be of substantial importance.
Here, we present a novel approach to amplify VCD signals based on the controlled modulation of the energies of the electronically excited-state manifold. In a first example, we employ electrochemical modulation and show that VCD enhancements by one order of magnitude can be achieved. In a second approach, we adapt the excited-state manifold by using an auxiliary to provide electronically excited states with the appropriate properties. In this case we find that amplification factors of more than two orders of magnitude can be obtained, bringing vibrational differential absorption on an equal footing with electronic differential absorption. Finally, we will discuss an all-optical amplification approach based on preparing molecules in electronically excited states.
|Last modified:||22 October 2012 2.31 p.m.|