The nature of chirality induced by molecular aggregation and self-assembly.

In this paper, we theoretically analyze the nature of chirality induced by molecular self-assembly with molecular dynamics and visualization methods. Firstly, the dynamics of molecular self-assembly of biphenylenes system are demonstrated in detail. Secondly, the molecular interactions for the assembled molecules are analyzed with the weak intermolecular forces. Thirdly, electron-hole coherence and charge transfer in optical absorption are demonstrated with a transition density matrix and charge difference density, respectively. The detailed visualized analysis of electric and magnetic transition dipole moment integrals reveals the nature of chirality of assembled molecules in electronic circular dichroism (ECD) spectroscopy. The Raman optical activity (ROA) spectra demonstrate that the chirality of assembled molecules is strongly dependent on the pre-resonance Raman spectra, based on the optical absorption and ECD spectroscopy. Our visualized analysis method can well reveal the nature and origin of chirality of molecular self-assembly.