Design of Bis(1,10-phenanthroline) Copper(I)-Based Mechanochromic Indicators

In the growing field of single-molecule mechanochromism, the potential of transition metal complexes is yet to be examined . In this work, we have synthesized a series of [Cu(phen)(2)](+) complexes: bis-Cu(I)-phenanthrol i n e , bis-Cu(I)-phenanthroline-2-amine, and bis-Cu(I)-phenanthroline-2-acetamide. After that, we characterized the complexes by UV-vis spectroscopy and employed density functional theory (DFT) calculations to investigate the changes in UV-vis upon mechanical pulling via force calculations. The results of our examination of time-dependent (TD)-DFT-calculated UV-vis suggests that the bis-Cu(I)-phenanthroline-2-acetamide complex is predicted to have an observable shif t of the metal-to-ligand charge transfer band upon pulling from 0 to 0.6 nN in the visible region. We have demonstrated the abi l i t y to synthesize and characterize bis-Cu(I)-phenanthroline-2-acetamide. In addition, the TD-DFT calculations predict an observable shift in the visible region of the UV-vis spectrum. This indicates that transition metal complexes are feasible candidates as mechanophores and are worthy of further exploration as to their potential role in a new subclass of mechanochromic indicators.

Automated summary

In this work, a series of copper complexes were synthesized and characterized. The changes in UV-vis spectrum under mechanical pulling were investigated using UV-vis spectroscopy and density functional theory calculations. The results suggest the potential of copper complexes as mechanophores for mechanochromic indicators.