Superatoms-Induced Effects of Phenalenyl π-Dimer on NICS and NLO Properties: Not Always Enhancement

5 years ago

Superatoms-Induced Effects of Phenalenyl π-Dimer on NICS and NLO Properties: Not Always Enhancement

Hong-Liang Xu, Feng-Yi Zhang, Zhong-Min Su

The introduction of the Li₃O and BeF₃ can exhibit an interlayer charge-transfer transition character for pure phenalenyl (PLY) dimer. A considerable question emerged: Can we modulate the interlayer charge-transfer transition character with different superalkalis and superhalogens? In the present work, nine complexes were designed with three superalkalis (Li₃O, Li₃S, and Na₃O) and three superhalogens (BeF₃, BeCl₃, and MgF₃) introduced into the PLY dimers, respectively. Results showed that the geometric structure, interlayer charge transfer, and electron transition character of PLY dimer were alternated by the superalkalis and superhalogens, especially for superalkali, with the increasing atomic number for alkali metals, interlayer distance and interaction energy between PLY monomers increased, while first hyperpolarizability (β_tot) decreased. The results of TD-DFT calculation indicated that the variation of β_tot was mainly caused by the alteration of the difference of the dipole moments between the ground state and the crucial excited state Δμ. Otherwise, due to the introduction of superatoms, the distribution of HOMO and LUMO was changed greatly as compared to that of pure PLY dimer. In addition, aromaticity was also analyzed, and it was intriguing to find that introduction of superatoms caused asymmetric distribution of aromaticity along the central-carbon axis. All of the above consequences suggested that the introduction of superatoms was really an effective strategy to alter the structure and the nonlinear optical property of the system.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b05234

DOI: 10.1021/acs.jpcc.7b05234