Properties. The absorption spectra of crystalline 1-R and 1-S exhibit two major peaks around 230 nm and 280 nm (Figure ). The circular dichroism (CD) spectra in the crystalline state display a distinct mirror pattern for the crystals of both enantiomers, with a major CD response at approximately 310 nm. At the same time, variable temperature CD measurements of crystalline samples in 213K-333K range indicated a slight decrease in the CD signal (Figure ), while the absorption spectra show a slight increase (Figure ) upon heating. This indicates that the observed changes on the CD spectra at different temperatures may not be related to electronic effects but rather to a potential "loss" of chirality at the high temperature. The conducted TD-DFT calculations [PBE0-D3(BJ)/def2SVP+MDF60 level] for the solid-state structure of 1-S showed good agreement with experimental CD data (Figure ). Notably, the major CD absorption peak (furtherly used for photoexcitation) corresponds to the S0→S1 and S0→S2 transitions, which are mainly attributed to ligand-to-ligand (LLCT) and metal-to-ligand (MLCT) charge transfers from the para-phenylene bridging ligand and the Au(I) atom to the NHC ligands, involving their phenyl substituents (Figure ). Therefore, their rotational motion may impact the chiroptical properties of 1-R and 1-S. 1-R and 1-S exhibit relatively weak photoluminescence in dichloromethane solution, with a single broad band emission maximum at 396 nm (Figure ) and a quantum yield (ΦPL) of approximately 3%. Notably, the studied complexes do not display any Circularly Polarized Luminescence (CPL) signal in solution, regardless of the excitation wavelength (Figure ). At the same time, their crystallization leads to a dramatic increase in ΦPL at room temperature up to approximately 30%, with a general red shift of the emission profile displaying two major peaks at 466 and 496 nm (Figure ). Such behavior is characteristic of aggregation-induced emission systems and relies on the restriction of the intramolecular motion model, suggesting the suppression of motion-induced emission quenching in the solid state. Remarkably, the obtained crystalline complexes also demonstrate thermo-responsive emission properties, with approximately a 2-2.5-fold increase in luminescent intensity upon cooling from 333K to 213K (IPL, Figure ,b, Figure ) while preserving almost the same emission profile and lifetime (Figure and Table ). Previously, we observed the similar behavior for relevant organogold(I) crystalline molecular rotors and associated it with the effect of phenylene or pyrazine moiety rotational motion on the excited state deactivation through a nonradiative relaxation pathway. Unlike in solution media, the crystalline 1-R and 1-S display clear mirrored CPL signals with two maximums at 466 nm and 496 nm under excitation at 315 nm (Figure ). Notably, the CPL signal has the opposite sign compared to their CD signals. Similar to the general emission intensity (IPL) of 1-R and 1-S, the CPL intensity (ΔICPL) also shows a strong dependence on temperature, increasing up to 4-fold upon cooling from 333K to 213K (Figure ). While both the IPL and ΔICPL show an increase with cooling, the ΔICPL rises faster with temperature increase. This also suggests a change in the luminescence dissymmetry factors (glum) of crystalline 1-R and 1-S, which increase almost up to ~50% with cooling (Figure ), from ±3-6 × 10 -3 at 333K to ±7-9 × 10 -3 at 213K (Table ). The obtained |glum| values of 1-R and 1-S complexes are above those of the recently reported crystalline chiral aminocarbene Au(I) complexes (0.1-5.8 × 10 -3 ). In order to ensure the reproducibility of the temperature effect on ΔICPL and glum values, measurements for each complex were conducted using three independently prepared crystalline samples. Moreover, the thermal reversibility of the effect was confirmed on the crystalline sample of 1-R using three heating-cooling cycles from 333K to 213K (Figure ).