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Dynamic Electron Delocalization and Spin-Spin Interactions in Redox Active Organic Polygons

Speaker

Yilei Wu,Department of Chemical Engineering, Stanford University, USA

Time

2019.01.02 10:00-11:00

Venue

Room 518, Chemistry Building A

Abstract

My research interests, which span organic, inorganic, physical and biochemistry, have focused broadly on photo- and redox-active molecules, especially those involving organic electronics, photovoltaics and spintronics, as well as molecular recognition and fluorescence imaging.[1-9] My PhD research under the joint supervision of Professor Wasielewski and Professor Fraser Stoddart has concentrated upon understanding electronic and magnetic coupling among multiple chromophoric and redox units in rigid and well-defined molecular architectures. We have reported on the synthesis, characterization and application of a series of chiral shape-persistent macrocycles comprising two, three and four equivalent rylene diimide units. We have investigated how the molecular geometry of redox-active diimides within these molecular “polygons” affects the physical properties associated with (i) through-space electron sharing, (ii) excited-state dynamics, (iii) spin-spin coupling, (iv) their cooperative solid-state packing and (v) their unusual redox behavior. These investigations demonstrated the potential of shape-persistent diimides-based macrocycles to carry out long distance electron transport required for organic electronics and photovoltaics applications. Moreover, we also studied the role of electron sharing on photoinduced electron transfer reactions, and the related spin coherence transfer dynamics, by utilizing these macrocycles as electron acceptors. Specifically, we have shown that the rapid electron hopping in photogenerated radical pair can shorten the spin coherence lifetime by mean of time-resolved optical, vibrational and electron paramagnetic resonance spectroscopies.[9] In order to furthers my understanding of charge and spin transport in organic materials I have joined Professor Zhenan Bao’s group at Stanford University as a postdoctoral fellow. I am currently working on structure-property relationships in organic semiconductors and their application in flexible electronics and photovoltaics.