Pyrrolopyrrole-Based Materials for High Contrast Electrochromics
Disciplines
Computational Chemistry | Materials Chemistry | Organic Chemistry | Polymer Chemistry
Abstract (300 words maximum)
Electrochromic films are traditionally dominated by cathodically coloring polymers that suffer from residual absorbance of visible light when oxidized, which limits the maximum contrast when these materials are studied as films. Alternatively, anodically coloring electrochromic (ACEs) offer a potential solution to overcome the residual absorbance by absorbing ultraviolet light when neutral and visible light when oxidized. Unfortunately, ACEs are dominated by discrete molecules that are not solution-processable and require an increased synthetic complexity for attaining electrochromes amendable to forming films. Motivated to exploit the synthetic simplicity associated with pyrrolo[3,2-b]pyrrole (DHPP) molecules and the ability to incorporate diverse functionalities that readily manipulate optoelectronic properties, a family of DHPP chromophores was synthesized and studied as color-controlled ACEs. As molecules in solution, the DHPP chromophores absorb in the ultraviolet region of the electromagnetic spectrum and display vibrant colors in their oxidized states, demonstrating color-controlled DHPPs. Beyond fundamental studies into the influence of functionality on optoelectronic properties of molecules, and guided by theory, two DHPP-containing copolymers were synthesized to enable solution processability. Both polymers absorb in the UV region of the electromagnetic spectrum in their neutral state and, upon oxidation, produce colored films. Through this theory-guided approach, the residual absorbance associated with cathodically coloring electrochromes is eliminated while simultaneously demonstrating the first example of a solution-processable anodically coloring DHPP-based copolymer.
Academic department under which the project should be listed
Department of Chemistry and Biochemistry
Primary Investigator (PI) Name
Graham Collier
Pyrrolopyrrole-Based Materials for High Contrast Electrochromics
Electrochromic films are traditionally dominated by cathodically coloring polymers that suffer from residual absorbance of visible light when oxidized, which limits the maximum contrast when these materials are studied as films. Alternatively, anodically coloring electrochromic (ACEs) offer a potential solution to overcome the residual absorbance by absorbing ultraviolet light when neutral and visible light when oxidized. Unfortunately, ACEs are dominated by discrete molecules that are not solution-processable and require an increased synthetic complexity for attaining electrochromes amendable to forming films. Motivated to exploit the synthetic simplicity associated with pyrrolo[3,2-b]pyrrole (DHPP) molecules and the ability to incorporate diverse functionalities that readily manipulate optoelectronic properties, a family of DHPP chromophores was synthesized and studied as color-controlled ACEs. As molecules in solution, the DHPP chromophores absorb in the ultraviolet region of the electromagnetic spectrum and display vibrant colors in their oxidized states, demonstrating color-controlled DHPPs. Beyond fundamental studies into the influence of functionality on optoelectronic properties of molecules, and guided by theory, two DHPP-containing copolymers were synthesized to enable solution processability. Both polymers absorb in the UV region of the electromagnetic spectrum in their neutral state and, upon oxidation, produce colored films. Through this theory-guided approach, the residual absorbance associated with cathodically coloring electrochromes is eliminated while simultaneously demonstrating the first example of a solution-processable anodically coloring DHPP-based copolymer.