title: A Study of Boratriazaroles: An Underdeveloped Class of Heterocycles.
abstract: Boratriazaroles were discovered in the late 1960s, and since then, a variety of substituted boratriazarole derivatives have been prepared. However, no study has compared the properties of these BN heterocycles with their carbon-based analogues. In this work, we have prepared a series of boratriazarole derivatives and have investigated how structural variations in the five-member heterocycle affect photophysical and electronic properties. Boratriazaroles exhibit absorption and emission spectra comparable to those of their azacycle analogues but have a markedly lower quantum yield. The quantum yield can be increased with the incorporation of a 2-pyridyl substitution on the boratriazaroles, and the structural and optoelectronic properties are further influenced by the nature of the B-aryl substituent. Introducing an electron-deficient p-cyano group on the B-phenyl substituent creates a twisted intramolecular charge transfer state that causes a large Stokes shift and positive solvatochromism. Our work should serve to guide future synthetic efforts toward the application of boratriazaroles in materials science.
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Sean K
authors: SK
authors: Liew
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Aleksandra
authors: A
authors: Holownia
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Andrew J
authors: AJ
authors: Tilley
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Elisa I
authors: EI
authors: Carrera
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Dwight S
authors: DS
authors: Seferos
authors: Davenport and Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors: Andrei K
authors: AK
authors: Yudin