Abstract: This study presents a novel physicochemical experiment investigating the mechanochromic behavior of a copper(I)-alkynyl coordination complex (Ph―C≡C―Cu_2.5). Utilizing the compound of Ph―C≡C―Cu_2.5 independently developed by our group as a model system, the experimental protocol involves monitoring macroscopic color responses under controlled mechanical stimuli (vertical pressure and shear forces), coupled with spectroscopic characterization through UV-Vis absorption and steady-state fluorescence measurements. The systematic investigation elucidates the relationship between mechanical-force-induced structural modifications and optoelectronic property variations, demonstrating a direct structure-activity correlation. Integrating principles from physical chemistry and advanced analytical techniques, this experiment enhances students’ understanding of mechanoresponsive materials while fostering critical thinking through mechanistic analysis of supramolecular interactions.

Key words: Ph―C≡C―Cu_2.5, Mechanochromism, Structure-activity relationship, Vertical pressure, Shear forces