Fall Speaker Meeting: Dr. David Bialas

Please join the Erie ACS on Wednesday, November 15th for our November speaker meeting! The section is pleased to welcome Dr. David Bialas, Assistant Professor of Chemistry at Penn State Erie, The Behrend College, who will present research on the “Insight Into the Optical Properties of Organic Dye Aggregates”. The talk will be held at Penn State Behrend in the Hammermill Building, Room 144 at 6:30 pm. No RSVP is required to attend the talk.

All Erie ACS members and chemistry students are invited to have dinner at 5:00 PM with Dr. David Bialas at the Harbor House located at 4454 Buffalo Rd, Erie before the talk. Those interested in attending dinner should RSVP using this evite invitation http://evite.me/nyTUSHAgmX by Monday, November 13th. 

Abstract:

In the last two decades, organic dyes have gained tremendous research interest due to their potential for application in organic photovoltaics, electronics and bioimaging. In this talk, the synthesis and aggregation studies of perylene bisimide and squaraine dyes will be presented. Traditionally, the optical changes upon aggregation have mainly been attributed to a long-range Coulomb interaction between the chromophores. However, in these studies the optical features of the aggregates cannot be rationalized by this traditional exciton coupling model. Instead, the close spatial proximity of the dyes leads to significant orbital overlap causing a short-range coupling as revealed by quantum chemical calculations. This short-range coupling can significantly alter optical signatures and the properties of materials. To conclude the talk, I show the first experimental proof of a perylene bisimide “null-aggregate”, in which the long- and short-range exciton coupling fully compensate each other, deceptively resembling a monomer absorption spectrum.