Date of Graduation

Spring 2018

Degree

Master of Science in Chemistry

Department

Chemistry

Committee Chair

Matthew Siebert

Keywords

physical organic chemistry, computational chemistry, DFT, CASSCF, Lawesson's reagent, bifluorenylidene, organic photovoltaics, 1, 2-dioxetane, 1, 2-dithietane

Subject Categories

Organic Chemistry | Physical Chemistry

Abstract

The ambition of this work is to start a path to the a priori rational design of high yield production for electron acceptors with finely tuned band gaps, from the comfort of an armchair. To this end, organic photovoltaics offer a cheap and sustainable means of manufacture using readily available materials and avoids the toxicity of some of the heavy metals used in first and second-generation solar cells such as cadmium. The microwave assisted Lawesson’s reagent mediated one-pot one-step solventless synthesis takes less than 3 minutes and results in an 84% yield of 9,9’-bifluorenylidene from two equivalents of fluorenone. While fullerenes have traditionally been the most widely used electron acceptors in organic photovoltaics, bifluorenylidenes have been gaining attention due to their superior absorption in the visible spectrum, highly tunable band gap and cheap/efficient synthesis. Using an analog system to study the reaction divided into two parts; intermediate formation and sulfur extrusion, a molecular pathway has been devised that fits the reaction conditions and explains differences in % yields of substituted 9,9’-bifluorenylidenes reported in a manner readily conducive to making predictions based on the substituents chosen in the 9-fluorenylidene scaffold.

Copyright

© Andrew Jourdan Eckelmann

Open Access

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