Syntheses of new ladder molecules and exploration of their electrical and optical properties

University Of Chicago, Chicago IL

Investigators

Abstract

Professor Luping Yu of the University of Chicago is supported by the Macromolecular, Supramolecular and Nanochemistry (MSN) Program of the Division of Chemistry to develop synthetic approaches to prepare new electron donor-acceptor molecular building blocks and link them together in small chains termed oligomers. The oligomers have the shape of a ladder. The ladder oligomers are investigated to determine the relationship between molecular structure and function as electric charge transporters. The objective is to develop oligomers with enhanced emission of electrons as a result of absorption of light. The project integrates synthetic chemistry, material science, theoretical computation and device generation. The ultimate goal is to establish the foundation upon which useful organic materials are developed for potential applications in organic light emitting transistor (OLETs) and other molecular electronic devices. The intellectual properties developed during the course of conducting the project is commercialized by industrial partners. Another goal of this project is to nurture the next generation of scientists in materials chemistry and electronic device generation. Students and other professionals receive interdisciplinary training and learn the skills necessary to face future scientific challenges. Underrepresented minority students are involved in the project and encouraged to pursue scientific careers. Conjugated ladder oligomers are a class of important materials that exhibit interesting optical and electrical properties. In this project, synthetic approaches involving several annulation reactions to ladder oligomers containing new electronic donor-acceptor (D-A) building motifs are developed. New concepts with emphasis on improved solubility and improved optoelectronic properties are formulated and a new generation of D-A ladder oligomers with unique charge transport properties are explored. Theoretical calculations are employed to inform the synthetic effort. These oligomers represent a new classis of organic semiconductors with controlled band gap, orbital energy levels and crystal structures. The electrical and optical properties of these materials and the relationship between molecular structure/crystal structure and charge transport property (mobility) are investigated. The aim is to prepare ladder oligomers with enhanced photoemission efficiency for applications in organic light emitting transistor (OLETs) and other electronic devices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.