Chen Wei, Li Zhi-Ru, Wu Di, Li Ying, Sun Chia-Chung, Gu Feng Long
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Chang-Chun, China.
J Am Chem Soc. 2005 Aug 10;127(31):10977-81. doi: 10.1021/ja050601w.
A new compound with electride characteristics, Li@calix[4]pyrrole, is designed in theory. The Li atom in Li@calix[4]pyrrole is ionized to form a cation and an excess electron anion. Its structure with C(4v) symmetry resembles a cup-like shape. It may be a stable organic electride at room temperature. The first hyperpolarizability of the cup-like electride molecule is first investigated by the DFT (B3LYP) method. The result shows that this electride molecule has a considerably large first hyperpolarizability with beta(0) = 7326 au (63.3 x 10(-30) esu), while the beta(0) value of the related calix[4]pyrrole system is only 390 au. Obviously, the Li atom doped in calix[4]pyrrole brings a dramatic change to the electronic structure, so that the first hyperpolarizability of Li@calix[4]pyrrole is almost 20 times larger than that of calix[4]pyrrole. We find that the excess electron from the Li atom plays an important role in the large first hyperpolarizability of Li@calix[4]pyrrole. The present investigation reveals a new idea and different means for designing and synthesizing high-performance NLO materials.
理论上设计了一种具有电子化物特性的新型化合物Li@杯[4]吡咯。Li@杯[4]吡咯中的锂原子被电离形成一个阳离子和一个多余的电子阴离子。其具有C(4v)对称性的结构类似杯状。它可能是室温下稳定的有机电子化物。首次采用DFT(B3LYP)方法研究了杯状电子化物分子的第一超极化率。结果表明,该电子化物分子具有相当大的第一超极化率,β(0)=7326 au(63.3×10⁻³⁰ esu),而相关杯[4]吡咯体系的β(0)值仅为390 au。显然,掺杂在杯[4]吡咯中的锂原子给电子结构带来了显著变化,使得Li@杯[4]吡咯的第一超极化率几乎是杯[4]吡咯的20倍。我们发现来自锂原子的多余电子在Li@杯[4]吡咯的大第一超极化率中起重要作用。本研究揭示了设计和合成高性能非线性光学材料的新思路和不同方法。