Details

Autor(en) / Beteiligte

• Matsui, Hiroshi
• Fukuda, Kotaro
• Takamuku, Shota
• Sekiguchi, Akira
• Nakano, Masayoshi

Titel

Theoretical Study on the Relationship between Diradical Character and Second Hyperpolarizabilities of Four-Membered-Ring Diradicals Involving Heavy Main-Group Elements

Ist Teil von

• Chemistry : a European journal, 2015-01, Vol.21 (5), p.2157-2164

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• By using spin‐unrestricted density functional theory methods, the relationship between the diradical character y and the second hyperpolarizability γ (the third‐order nonlinear optical (NLO) properties at the molecular scale) for four‐membered‐ring diradical compounds, that is, cyclobutane‐1,3‐diyl, Niecke‐type diradicals, and Bertrand‐type diradicals, were investigated by focusing on the substitution effects of heavy main‐group elements as well as of donor/acceptor groups on the y and γ values. It has been found that i) γ is enhanced in the intermediate y region for these four‐membered‐ring diradicals, ii) Niecke‐type diradicals with intermediate y values, which are realized by tuning the combination of the main‐group elements involved, exhibit larger γ values than Bertrand‐type diradicals, and iii) the y value and thus γ value can be controlled by modifying the both‐end donor/acceptor substituents attached to carbon atoms in Nicke‐type C2P2 diradicals. These results demonstrate that four‐membered‐ring diradicals involving heavy main‐group elements exhibit high controllability of the y and γ, which indicates the potential applications of four‐membered‐ring diradicals as a building block of highly efficient open‐shell NLO materials. Relationship issues: The relationship between the diradical character (y) and second hyperpolarizability (γ; third‐order nonlinear optical property) for several four‐membered‐ring diradicals involving heavy main‐group elements was investigated (see figure). It is found that γ is enhanced in the intermediate y region, and that y and γ can be controlled by modifying the main‐group elements and the donor/acceptor groups substituted into the four‐membered ring.