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杯[4]芳烃对单糖及嘧啶衍生物的分子识别和分子开关 总被引:1,自引:0,他引:1
用AM1和INDO/SCI方法对八羟基杯[4]芳烃与单糖及嘧啶衍生物形成的超分子体系进行理论研究,结果表明,主体通过CH-π相互作用对单糖类进行分子识别,尤其对赤藓糖识别效果更好;主体与嘧啶没有明显的π-π堆砌作用,但能识别含吸电子基团的嘧啶衍生物,据此可设计酸碱调控的分子开关.讨论了配合物的UV谱带与主体相比发生红移的原因. 相似文献
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用INDO系列方法对C77Si的21种可能异构体进行了理论研究,表明最稳定异构体是由C78(C2v)椭球长轴所穿过的六元环上原子C35被Si取代所形成的,椭球短轴附近的原子不宜被取代;C77Si光谱吸收峰与C78相比发生红移,讨论了吸收峰红移的原因. 相似文献
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用AM1及MNDO方法对环双(对-苯基-对草快)与中性客体的配合物进行理论研究,得到稳定化能和配合物相互转换的△△E值;以AM1优化构型为基础,用INDO/SCI方法计算4种配合物光谱,并用AM1方法计算主体与二苯醚衍生物在H^ 存在下的势能曲线,探讨分子开关形成机理。 相似文献
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用INDO(Intermediate neglect differential overlap)系列方法对Cn78进行系统研究.结果表明,Cn78(G2v)比Cn78(C2v')稳定;Cn78(C2v)和Cn78(C2v')未发生Jahn-Teller畸变;Cn78随n绝对值增大,体系能量升高.以优化构型为基础,首次计算Cn78电子光谱,对电子跃迁进行理论指认,讨论Cn78光谱特征吸收与C78相比发生红移的原因. 相似文献
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Twenty-tow possible isomers for C76BN were studied by INDO methods. The two most stable geometries are 52,53-C76BN and 29,28-C76BN, in which boron and nitrogen atoms are connected with each other and located at the 6/6 bond near the longest axis of C78(C2v). Electronic spectra of C76BN were investigated with INDO/SCI method. UV absorptions of C76BN are red-shifted compared with those of C78(C2v). The structures and IR spectra for the four stable isomers of C76BN were calculated by AM1 method. It was indicated that the substitution of the BN unit weakens the conjugation of carbon atoms, leading to the decrease of IR frequencies. 相似文献
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The semi-empirical INDO method was used to study the electronic structures and the spectra of all of the 34 possible isomers of C78O based on C78 with group C2v. This calculation can simulate positions of an additional oxygen atom in C78 and predict the spectroscopic characteristics of the isomers. The most stable geometry of C78O is the 73,78-C78O molecule with an epoxide structure. The added 73,78-bond is located between two hexagons (6-6) and is intersected by the shortest C2 axis in C78 with group C2v. Atomic orbitals of the oxygen atom play an important role in lowering HOMO energy of 73,78-C78O. Compared with C78 with group C2v, the blue-shift in the electronic absorption spectrum for 73,78-C78O was observed.The reason of the blue-shift effect was discussed, and the electronic transitions were assigned based on the theoretical calculations. 相似文献
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Kx C76 不同于 K3C6 0 的半导体行为 [1]引起了我们对 Cn- 76 的研究兴趣 .自 Ettl[2 ]分离表征 C76 以来 ,相应的实验及理论研究已经开始 [3,4 ] ,但对 C- 76 以外其它离子的电子结构和光谱的理论研究尚未见报道 .本文用 INDO系列方法对 Cn76 进行系统研究 ,考察其是否发生 Jahn-Teller畸变 ,首次计算了 Cn76 单态离子的电子光谱 ,对电子跃迁进行理论指认 ,讨论了 Cn76 光谱的特征吸收与 C76 相比发生红移的原因 .1 研究方法以球心为坐标原点 ,将 C76 椭球体水平放置 ,取最短轴为 z轴 ,按 D2 [2 ]对称性作出 C76 的初始坐标 ,用 … 相似文献