Carborane-Decorated Siloles with Highly Efficient Solid-State Emissions - What Drives the Photophysical Properties?

New hybrids were synthesised by linking carboranes and siloles, both of which are known as aggregation-induced emission active units. Although most of the newly synthesised systems do not display notable quantum yield either in solution or in the aggregated state, they emit strongly in the solid-state, and a quantum yield of up to 100 % can be achieved. The tailorable quantum yield can be attributed to the packing of the molecules in the crystal lattice ruled by the carborane and phenyl moieties according to the SC-XRD data. Our experimental results, complemented by density functional theory calculations, show that the silole moiety primarily influences the photophysical properties. At the same time, the carborane serves as a steric building block without direct responsibility for the aggregation-induced emission property. The patterns of substituents can alter the absorption and emission properties.