Aggregation-Induced Emission Governed by Self-Assembly Pathways in NHC-Au(I) Carbazolate Complexes

Aggregation-induced emission has emerged as a powerful strategy to develop luminescent materials with enhanced solid-state performance. Here, we report two N-heterocyclic carbene (NHC) gold(I) complexes, featuring a donor-metal-acceptor architecture composed of a carbazolate donor, a linear Au(I) bridge, and cyano-substituted acceptor units. Both complexes display strong luminescence upon aggregation. Isophthalonitrile derivative forms orange-emissive supramolecular fibers stabilized by π-π stacking, where metallophilic Au···Au interactions are present. The benzonitrile derivative, lacking any aurophilic interactions, exhibits pathway complexity, initially generating a metastable green emissive aggregate that slowly converts into a thermodynamically stable orange assembly. Photophysical studies highlight the coexistence of fast nanosecond fluorescence and long-lived charge-transfer phosphorescence. Here, we show how molecular design dictates supramolecular dynamics and offers a route to programmable emissive behavior in metal-based AIE systems.