Highly-efficient solid-state emission of tethered anthracene-o-carborane dyads and their visco- and thermo-chromic luminescence properties

A facile and efficient method is described to greatly improve the emission efficiency of anthracene-o-carborane dyad by linking two o-carborane building blocks together through tailored alkyl linkages. Improvement of the emission efficiency of the tethered anthracene-o-carborane dyads was achieved with the quantum yield up to 40.8% and 51.4% for BCAC4 and BCAC6 respectively, in contrast to that of CAH (4.3%) and CAA (36%), demonstrating that the cooperation advocates that one plus one is much bigger than two. In addition, these developed emissive AIE luminogens exhibit impressive response to the environmental stimuli of viscosity and temperature. DFT calculations were carried out to explore the influence of the anthryl and alkyl linkages on emission efficiency. Our materials and concepts are useful as a guideline for designing o-carborane-containing highly-efficient solid luminescent materials with stimuli-responsive properties.