Abstract:
A cationic iridium(Ⅲ) complex (ppy)
2Ir(DPPTA)PF
6 was synthesized by using 2-phenylpyridine (ppy) as main ligand and N, N-diphenyl-4-(4-phenyl-5-(pyridin-2-yl)-4
H-1,2,4-triazol-3-yl)aniline (DPPTA) as ancillary ligand. This complex showed mechanochromic luminescence with high contrast. When it was just obtained via precipitating from CH
2Cl
2 solution, it emitted green light and the maximum emission wavelength (λ
em,max) was 525 nm. It emitted yellow light (λ
em,max=576 nm) after it was ground, then it emitted yellow-green light (λ
em,max=531 nm) when it was fumed by CH
2Cl
2. The color changes caused by grinding and fumigation can be repeated for many times with high stability, the difference of the λ
em,max in two states was as high as 45 nm. The emissive color of (ppy)
2Ir(DPPTA)PF
6 was sensitive to mechanical force and being fumed by organic solvents, but it was not sensitive to temperature changes, which was different from many reported mechanochromic luminescence materials.