【作者】 王银锋；

【导师】 孙家钟； 李志儒；

【作者基本信息】 吉林大学 ， 物理化学， 2010， 博士

【摘要】 本论文中对若干具有拓扑兴趣的的分子：分子笼、分子篮和分子瓶体系进行了理论研究。主要贡献在于以下六个方面：(1)首次预测了有趣的Mobius篮子分子的结构及其光学性质。展现了成篮效应和扭曲效应对结构和光学性质等的影响,特别是提出了改变分子结构来实现电荷迁移方向控制的可能性。(2)类Klein分子瓶是否存在对化学是一个挑战。首次设计并研究KB-C318、KB-C320和KB-C374三个类Klein分子瓶。发现类Klein分子瓶具有接近于C36和C74分子的稳定性,这些Klein瓶分子可作为一个新的碳瓶家族。(3)首次使用一个大分子笼子C60F60束缚一个额外电子得到单分子溶剂化单电子体系。它们是一种新的内接化合物--电子内接化合物。发现了稳定性与笼子形状的关系,提出了形成单分子溶剂化单电子的条件。(4)首次使用一个双笼子分子来束缚一个电子,首次实现了电子定域化的结构和轨道,并发现了电子定域化跃迁存在。找到了控制电子定域化跃迁的可能性。(5)首次报道了苯的环二聚体体系中的分子内环间σ／(π／π)共价相互作用及其与分子结构特性间的关系。提出了环间多中心多电子σ／(π／π)键,讨论了相互作用能及其决定性影响因素。本论文中出现的长的第四种C-C(1.561～1.628 (?))键引起了国际同行的关注(美国橡树岭国家实验室等)。(6)首次研究了新型金属-金属氧化物-非金属夹心超碱金属化合物Li3OMC5H5 (M=Be, Mg和Ca)的结构和性质。提出了面外σ-芳香性的存在条件,揭示了它们的碱金属化物和电子化物的特征。更多还原

【Abstract】 The structures and properties of the topologically interesting molecules including cage, basket and bottleTopologically interesting molecules represent a permanent challenge for synthetic chemists and theoreticians。In this paper, the structures of some cage-like, basket-like, and bottle-like molecules are obtained for the first time. The stabilities and the special properties of these molecules are exhibited. This paper has enhanced the knowledge on novel physics and chemistry of the one-sided (nonorientable) surface, excess electron chemistry andπ/πinteraction. This paper also provides the new design approaches of the new optical and photoelectric materials and devices. Four aspects are included in this paper:(1) Study on the one-sided topologically interesting moleculeExpanding the non-knot region of the famous Mobius strip with topological one-sided characteristics, an interesting structure of Mobius basket molecule with all real frequencies was obtained at the B3LYP/6-31G(d) level for the first time. The twisted handle joints the outer and inner surfaces of the bowl to form a one-sided container molecule. Comparing the Mobius basket with its isomers of Mobius strip and normal basket, the framework shape effects on the structure and properties are systematically exhibited. Especially, (1) the basket-making effect increases kinetic stability (the HOMO-LUMO gap increases from 1.116 eV for Mobius strip to 1.608 eV for Mobius basket); (2) from the normal basket to the Mobius basket, the twisting effect obviously increases the static first hyperpolarizability (from 2836 to 3773 au) and IP (from 6.622 to 6.857 eV). It is found that the aza atom, knot, the bowl, and the combination of the knot and bowl units are important regulating factors for the charge transfer direction in the crucial transitions. This provides a possibility on the control of charge transfer direction in crucial transitions by the variation of the structures.How to construct the fantastic bottle molecule and reveal its stability is a theoretical challenge. The Klein bottle is a closed non-orientable (one-sided) surface in 4 dimension space and its immersion in 3 dimension space contains a one-sided closed, continuous curve of self-intersection between the bottleneck and bottle body. Here, by quantum mechanics method, we report a novel carbon-bottle family of Klein bottle molecules:KB-C318、KB-C320 and KB-C374. The stabilities of them are close to the stable C36 and C74 fullerenes, which indicates the existence of the family of Klein bottle molecules. A synthetic possibility of Klein bottle molecule is suggested in single-molecule level. This work may excite the experimental researches on chemistry and physics of the non-orientable surface.(2) Study on the cage-like single molecular solvated electron systemsUsing the one-cage-like molecule and double-cage-like molecules to trap the excess electrons, the new kind, of single molecular solvated electron systems, one-cage-like e-@C60F60(In and D6h) and double-cage-like e-@C24F22(NH)2C20F18 and e-@C20F18(NH)2C20F18 with all the frequencies are obtained at the B3LYP/6-31G(d)+4s4p level. They are new endohedral complexes, the electron endohedral fluorinated fullerene complexes. What kind of single molecular cages can encapsulate the excess electron? (1) The cage has polar bonds and the dipoles of those polar bonds are directed to the center of the cage to generate sufficiently interior attractive potential. (2) The cage is a saturated molecule and can provide an internal s-type LUMO for the occupancy of one additional electron. Owing to such excess electron localizations, the inter-cage excess electron transfer transition takes places. It corresponds to SOMO→LUMO transition between two s-type orbitals. This indicates that the inter-cage excess electron transfer transition may be controlled by regulating the molecular structure. This allows the design of materials with controlled intramolecular charge transfer for the photoelectric and nanoelectronic devices.(3) Study on the intra-molecular inter-ringπ/πinteraction.To study the inter-ringσ/(π/π) covalent interactions between non-radicalπ-systems, five structures of cyclodimers of benzene (C6H6)2 with all the real frequencies, i.e. o-p’-dibenzene (A), the pentacyclic dimer (B), p-p’-dibenzene (C), syn-o,o-dibenzene (D), and hexaprismane (E), are obtained at the MP2/6-311G (d, p) level. Five inter-ring bonding mode types forming the inter-ring multicenter multielectronσ/(π/π) covalent bonds are represented:A, ring-edge type between a butterfly-shaped ring and a planar ring (4-center 4-electron bond); B, edge-edge and ring-ring types between two identical butterfly-shaped rings (8-center 8-electron bond); C, ring-ring type between two identical butterfly-shaped rings (4-center 4-electron bond); D, edge-edge type between two identical planar rings (4-center 4-electron bond); and E, face-face type between two identical planar rings (12-center 12-electron bond). The order of the large inter-ring interaction energies at the MP2/6-311+G (3d, 2p)+BF level is-99.15 (A with two inter-ring C-C bonds)>-98.57 (B with four C-C bonds)>-85.76 (C with two C-C bonds)>-61.35 (D with two C-C bonds)>-60.40 kcal/mol (E with six C-C bonds). However, this does not show an obvious relationship between the interaction energy and the number of the inter-ring C-C bonds. The reason is that the number of decisive influencing factors of the inter-ring interaction energy is not one but five:the number of the favorable inter-ring C-C single bonds, the number of the unfavorable four-membered rings themselves, the participating number of the four-membered rings in unfavorable interaction among those rings, the number of the favorable non-planar melted six-membered ring, and the weak inter-ringπ/πinteraction (between twoπbonds in different rings).(4) Study on the novel sandwich-like superalkali compound.The structures of novel metal-[metal oxide]-nonmetal sandwich-like superalkali compounds, i.e., H- and T-shaped Li3OMC5H5 (M=Be, Mg and Ca), with all the real frequencies are obtained for the first time at the MP2/6-311+G(2d, p) level. Four factors to increase the NICS of Li3+ ring in Li3OMC5H5 systems are found. (1) Replacing the T-shaped structure with parallel Li3+ and C5H5 ring by the corresponding H-shaped structure with perpendicular Li3+ and C5H5 ring, the NICS value considerably increases from-7.8～－8.2 to-22.2～-43.4 ppm. (2) The existence of the neighboring alkaline earth metal oxide subunit evidently increases the NICS in H-shaped structures from about -11.1 to -16.1～－37.0 ppm. (3) Basing on the finding that the alkaline earth atomic number dependence of the aromaticity of Li3+ ring, the larger atomic number increases the NICS value. (4) The end C5H5" subunit increases the NICS value. For example, the increase is -6.4 ppm for H-shaped Li3OCaC5H5. In addition, the expected out-of-planeσ-aromaticity of Li3+ ring is not exhibited, in contrast to that in the sandwich-like structure of Li3OLi3 (J Chem Phys 2005,123,164306), but the in-planeσ-aromaticity of it is increased. Why? This is because (1) the size of the OM subunit near the Li3+ ring is small, and (2) the large-sized C5H5- subunit is far from the Li3+ ring. For these Li3OMC5H5, the H-shaped structure exhibits electride characteristics and the T-shaped structure with lithium anion exhibits alkalide characteristics.更多还原