Improved mechanochromism and mechanoluminescence in fluoro-substituted NNC-coordinating cyclometalated platinum (II) complexes

Mechanochromism and mechanoluminescence of a series of fluoro-substituted chiral Pt(NNC)Cl complexes have been investigated. With the grafting of F substitutes, the absorption and emission in the solution give an obvious blue-shift. The molecular stacking of solids may also be affected, leading to different mechanochromic and mechanoluminescent behaviors for obtained yellow or orange solid powders of cyclometalated platinum(II) complexes. Remarkably, yellow crystallites of (-)-3FC display a sensitive and contrast mechanochromic and mechanoluminescent phenomenon, with color changing from yellow to orange and luminescence changing from bright green to red (Delta.tem approximate to 125 nm). The ground solids can be recovered to original crystallites by adding a drop of acetone. Furthermore, the mechanochromic and mechanoluminescent behaviors can be reversible for multiple cycles without perceivable performance degradation.

Automated summary

The mechanochromic and mechanoluminescent properties of a series of fluoro-substituted chiral Pt(NNC)Cl complexes have been investigated, showing blue-shift in absorption and emission with F substitutes. Different mechanochromic and mechanoluminescent behaviors were observed in obtained yellow or orange solid powders of cyclometalated platinum(II) complexes. Notably, (-)-3FC yellow crystallites exhibit a sensitive and contrast mechanochromic and mechanoluminescent phenomenon, with color and luminescence changing significantly. The reversible nature of these behaviors with multiple cycles and the recovery of original crystallites with acetone drop were also demonstrated.