Yuxin Ren, Meiyu Jia, Cai-Cai Zhang, Pengcheng Jiang, Lukang Ji
A linear bola-type chiral conjugated gelator incorporating a naphthalene core, ethynyl linkers, and terminal chiral amide groups was designed and synthesized to investigate the spectroscopic features of solvent-dependent self-assembly and supramolecular chirality inversion. The compound formed stable supramolecular gels in both acetonitrile and tetrachloromethane, while exhibiting clearly different UV-vis absorption, fluorescence emission, and circular dichroism (CD) responses in the two media. In particular, opposite CD signals were observed, indicating inversion of supramolecular chirality under different solvent environments. The assemblies formed in tetrachloromethane showed bathochromically shifted absorption and emission bands together with a longer fluorescence lifetime compared with those formed in acetonitrile, suggesting stronger intermolecular electronic coupling and a more rigid aggregated state. FT-IR results further indicated solvent-dependent differences in the hydrogen-bonding environment of the amide groups. Combined with molecular dynamics simulations and theoretical calculations, the spectroscopic results reveal that solvent polarity plays a key role in determining the local packing mode of the aggregates. In acetonitrile, the molecules preferentially adopt an antiparallel arrangement of the naphthalene units, whereas in tetrachloromethane a parallel arrangement is favored, leading to a lower dipole moment, stronger intermolecular hydrogen bonding, and a more compact assembly structure. The calculated CD spectra of representative dimers are consistent with the experimental observations, supporting the proposed packing models. These results demonstrate that solvent-controlled reorganization of intermolecular packing can effectively modulate the spectral behavior and supramolecular chirality of a nonclassical bola-type conjugated system, and provide useful spectroscopic insight into the design of responsive chiral soft materials.