Abstract: A atomic precise gold-copper coordination polymer of [AuCu(L)2]n (L = phenylacetylene) was synthesized in this work, which exhibits excellent luminescent properties in the aggregated state. [AuCu(L)2]n has a one-dimensional chain-like structure and can be efficiently synthesized in a one-pot method at room temperature. Upon grinding, the color of [AuCu(L)2]n changes from yellow to red, and the emission wavelength red-shifting from 550 nm to 620 nm. Under the action of dichloromethane vapor, the red [AuCu(L)2]n powders can revert to yellow. This reversible change process exhibits excellent fatigue resistance, making [AuCu(L)2]n suitable for the application in fluorescent anti-counterfeiting materials. Mechanistic study shows that [AuCu(L)2]n transforms from a crystalline state to an amorphous state after grinding. Meanwhile, the original metal-metal bonds and a large number of π-π interactions within and between molecules are disrupted, blocking the long-range cluster center luminescence channel, which is the main reason for its luminescence and color change.

Key words: Coordination polymer, Gold-copper cluster, Mechanochromism