PUB - Publikationen an der Universität Bielefeld

Diazaborolyl anions are species with electronically and coordinatively unsaturated boron centers, and as six-electron systems they are analogues of the more familiar N-heterocyclic carbenes and N-heterocyclic silylenes. In contrast to the latter compounds lithium diazaborolyls are thermally unstable, they are extremely strong bases and versatile nucleophiles. With these properties they overcome the paradigm that low-coordinated borane derivatives are mainly electrophiles. In keeping with this, the metal diazaborolyls discussed here serve as excellent transfer reagents of the borolyl anion to main group elements and transition and rare earth metals. Thereby they establish a novel synthetic approach to the class of metal boryl complexes. A series of iridium complexes produced by this protocol have meanwhile found application as emitter materials in organic light-emitting diodes (OLEDs).