Construction of an Exciplex-Based Zero-Dimensional Complex with Dual Force-/Acid-Triggered Stimuli-Responsive Luminescence

Stimuli-responsive luminescent materials (SLMs) are capable of realizing the transition of luminescence properties by perceiving external stimuli, exhibiting great application potential in various emerging fields. Despite the increasing maturity of research regarding the design, synthesis, and modulation of properties of the single-SLMs, the development of efficient design strategies for multi-SLMs remains an area requiring further exploration and breakthroughs. Herein, a dual-ligand zero-dimensional cadmium complex [Cd(9-ADC) 2 (Phen) 2 ]·4.5H 2 O (9-HADC for 9-acridinecarboxylic acid and Phen for 1,10-Phenanthroline) was synthesized, exhibiting characteristic blue luminescence derived from the 9-ADC/Phen exciplex. External grinding disrupted the hydrogen bonds, π···π stacking, and C–H···π interactions between structural units, which in turn transformed the ordered crystal structure into an amorphous state, induced the spatial rearrangement of 9-ADC and Phen ligands, and ultimately achieved the mechanochromic luminescence (MCL) performance. The deprotonated 9-ADC ligand with dual proton-accepting sites (carboxylate group and acridine N atom) endowed the material with acid-responsive properties. Reversible protonation–deprotonation of 9-ADC under alternating acid–alkali fumigation drove dynamic disruption and reformation of the exciplex system, realizing reversible acidochromic luminescence (ACL) performance. This study provided substantial theoretical insights and experimental foundations for the targeted development of novel intelligent luminescent responsive materials.