Premium
Theoretical investigation of curved π‐conjugated fullerene flakes: open‐shell character, aromaticity, and third‐order nonlinear optical property
Author(s) -
Fukuda Kotaro,
Fujiyoshi Junya,
Minamida Yuka,
Nagami Takanori,
Matsui Hiroshi,
Ito Soichi,
Kishi Ryohei,
Kitagawa Yasutaka,
Champagne Benoît,
Nakano Masayoshi
Publication year - 2017
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.3581
Subject(s) - open shell , conjugated system , aromaticity , chemistry , singlet state , planar , shell (structure) , molecule , fullerene , molecular physics , computational chemistry , chemical physics , electronic structure , atomic physics , materials science , excited state , physics , organic chemistry , computer graphics (images) , computer science , composite material , polymer
Open‐shell singlet nature, aromaticity, and second hyperpolarizabilities of two kinds of curved π‐conjugated fragments of C 60 fullerene, called C 60 flakes, together with their corresponding planar analogues are theoretically investigated. It is found that one curved system, A-1 , exhibits intermediate open‐shell singlet nature, while the other structure, B-1 , and the two corresponding planar systems possess a closed‐shell ground state. The variation of the open‐shell singlet nature is explained by the number of Clar's sextets in the resonance structures, which is associated with the local aromaticity, as quantified by the NICS0 values. The calculated orientationally averaged second hyperpolarizabilities show that the intermediate open‐shell singlet system A‐1 exhibits the best performance, and that the other curved system B‐1 is the worst among the four C 60 flakes, whereas all systems exhibit better performance than the original spherical C 60 system. This tendency suggests that a lower dimensionality in the π‐conjugated structure is beneficial to the construction of efficient nonlinear optical molecules. The present results not only show that the open‐shell singlet system A‐1 is a performant nonlinear optical molecule, but they also contribute to a deeper understanding of the electronic structure of curved π‐conjugated molecules. Copyright © 2016 John Wiley & Sons, Ltd.