Fig. 4: Single-crystal structures revealing the formation of single and double helical π-aggregates.
From: Double helical π-aggregate nanoarchitectonics for amplified circularly polarized luminescence
a–c The single-crystal structure of L-TPE and its structural features. d The rotational configurations of TPE chromophore in L-TPE (left) and L-TPE/L-Fmoc (right) crystals. e The unit cell of L-TPE/L-Fmoc co-crystal. f–h The co-crystal structure of L-TPE/L-Fmoc and its structural features, g consists of three parallel stacked unit cells and the middle one was covered with a double-helix cartoon figure. i, j The average dihedral angel (α) of benzene ring/ethene plane (left figures) and the geometry relations of three nearest neighboring TPE chromophores (right figures) in L-TPE (upper) and L-TPE/L-Fmoc (bottom) crystals. The blue arrows indicate the direction of TPE transition moment. k Illustration of S0-S1 electric transition moment (μ) of TPEHis calculated by TD-DFT at B3LYP 6-311G** level and visualized by VMD program51, the z axis points outside the plane.
