Mechano-responsive circularly polarized luminescence of organic solid-state chiral emitters.

ABSTRACT: Two difluoro-boron ?-diketonate complexes bearing chiral amido groups have been synthesized. Their mechano-responsive luminescence and chiroptical properties have been investigated in the solid state. Both compounds display a bright blue-green emission and a significant circularly polarized luminescence (CPL) signal in the crystalline state, with |g _lum| values as high as 2.2-2.4 × 10^-2. A bathochromic shift in emission, together with a decrease of |g _lum| values to c.a. 3 × 10^-3, is induced upon application of a shearing stress. For the DFB-Hex-amide compound, interestingly, sign inversion of the anisotropy factor g _lum is observed under mechanical stimulation ("mechano-CPL effect"), which can be rationalized by a switching between monomer and excimer emission.

SUBMITTER: Louis M 

PROVIDER: S-EPMC6345345 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature