Reversible stimuli-responsive luminescence of bimetallic cuprous complexes based on NH-deprotonated 3-(2′-pyridyl)pyrazole

Color regulation of solid-state luminescence is desirable and challenging. Herein, we report two new three- and four-coordinate bimetallic cuprous complexes 1 and 2, which bear a NH-deprotonated 3-(2'-pyridyl)pyrazole adopting the monoanionic tridentate mu-eta(1)(N)eta(2)(N,N) bonding mode and exhibit reversible stimuli-responsive luminescence. It is revealed that the reversible stimuli-responsive luminescence for 1 and 2 is triggered by the destruction and restoration of orderly molecular stacking, along with the loss and recovery of the CH2Cl2 solvent molecules for 1. Virtually, this reversible stimuli-responsive luminescence originates from the breaking and rebuilding of various CH center dot center dot center dot O hydrogen bonds around ClO4-, as supported by X-ray single-crystal analysis, the H-1 NMR spectra, and the PXRD and FT-IR spectra in various forms. In addition, the possible applications of this reversible stimuli-responsive luminescence have also been investigated.

Automated summary

The reversible stimuli-responsive luminescence in the two newly reported bimetallic cuprous complexes 1 and 2 is triggered by the destruction and restoration of orderly molecular stacking, along with the loss and recovery of CH2Cl2 solvent molecules. This innovative reversible luminescence mechanism through breaking and rebuilding hydrogen bonds holds potential applications.