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11.
12.
环状芴基张力半导体由于其特殊的分子结构,发射状排布的p轨道和纳米级空腔等诸多特点,引起了科学家广泛的关注.相对于直链型芴基半导体,环状芴基张力半导体展现出独特的光电性质.然而,迄今为止其振动性质没有被报道.对四元环芴的晶体与直链四聚芴粉末样品进行拉曼光谱表征和归一化处理,并结合理论计算.结果表明,与直链寡聚芴相比,环芴类似于碳纳米管的G峰发生了偏移,并且低频区域拉曼频移峰的峰强增加.其原因是由于张力的引入,改变了芴基主链的骨架和电子结构,加强芴骨架上π电子离域,同时使环芴中每个芴单元都参与到振动中.该研究结果为芴基张力半导体材料拉曼光谱的研究提供了一定的工作基础. 相似文献
13.
Ludovic Jullien Jean-Marie Lehn 《Journal of inclusion phenomena and macrocyclic chemistry》1992,12(1-4):55-74
An approach to a transmembrane cation channel is described. It is based on the grafting of oxygen bearing side-chains on a macrocyclic polyether unit that constitutes the organizing core. The resulting species has a structure of overall bouquet shape. The synthesis of such a molecule .
M
0
,14a is described, together with that of its analogue bearing polymethylene side-chains
M
C
,14b. The physicochemical properties of these molecules indicate that they possess the features expected on the basis of their structure.This paper is dedicated to the memory of the late Dr C. J. Pedersen. 相似文献
14.
Sergey?P.?BabailovEmail author Lubov?D.?Nikulina 《Journal of inclusion phenomena and macrocyclic chemistry》2005,51(1-2):103-109
1H and 13C NMR measurements are reported for the CDCl3 and CD2Cl2 solutions of [La(NO3)3(18-crown-6)] (I), [Pr(NO3)3(18-crown-6)] (II) and [Ce(NO3)3(18-crown-6)] (III) complexes. Temperature dependencies of the 1H NMR spectra of II have been analyzed using the dynamic NMR methods for multi-site exchange. Two types of conformational dynamic processes in II were identified (the first one with activation enthalpy ΔH
‡=26 ± 4 kJ/mol is conditioned by interconversion of complex enantiomeric form and pseudorotation of macrocycle molecule upon the C
2 symmetry axis, the second one with ΔH
‡=46 ± 5 kJ/mol is conditioned by macrocycle molecule inversion). Studies of the values of the lanthanide-induced shifts revealed that the structure of complexes in solution is similar to that reported for the complex I in the crystal state.This revised version was published online in July 2005 with a corrected issue number. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(18):1965-1972
New metal-free phthalocyanine (7) fused symmetrically in peripheral positions with four dithiatetraoxa macrocycles, has been synthesized by cyclotetramerization of the isoindolinediimine derivative of macrocyclic 6. Metallophthalocyanine (8) was synthesized by reaction of phthalonitrile derivative (5) with anhydrous nickel(II) chloride. The new compounds were characterized by elemental analysis, 1H and 13C-NMR, IR UV–Vis and mass spectroscopies. 相似文献
16.
17.
Triphenylamine derivatized phenylacetylene macrocycle with large two-photon absorption cross-section
Zhen Fang Marek SamocRichard D. Webster Anna SamocYee-Hing Lai 《Tetrahedron letters》2012,53(36):4885-4888
A phenylacetylene macrocycle (PAM) derivative containing triphenylamine as the framework was synthesized in one-step Sonogashira coupling. The photophysical and electrochemical properties were investigated in details. This hexamer shows significant enhancement in two-photon absorption cross-section relative to reported PAM derivatives. 相似文献
18.
Abbas Shockravi Esmael Rostami Ali Dehjurian Rahim Tohidi Samad Bavili Tohidi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):535-541
Bis(dibenzosulfoxo)-27,30,35,38-tetramethyl-24-crown-6, bis(dibenzosulfoxo)-21,24,29,32-tetramethyl-18-crown-4, dibenzosulfoxo-15,18-dimethyl-12-crown-3 and dibenzosulfoxo-12,15-dimethyl-9-crown-2 macrocycles are synthesized by the reaction of 2,2′-sulfinyl-bis(4-methyl phenol)and 1,2-dibromoethane and diethyleneglycol di-p-toluenesulfonate. 相似文献
19.
Esmael Rostami 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1694-1701
Abstract New dinaphthosulfide aza oxa thia crowns from 1-naphthol were prepared. At first, 2,2′-thiobis(1-hydroxynaphthalene) (a dinaphthol) was prepared from 1-naphthol. Then diester was prepared from the reaction of dinaphthol and methylchloroacetate. Aza crowns were synthesized from the reaction of diester and diamines (ethylene diamine, 1,3-diaminopropane, 1,4-diaminobutane, and 1,6-diaminohexane) in methanol. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT 相似文献
20.
Abstract Chiral crystals of tryptamine and achiral carboxylic acids such as p-chlorobenzoic acid, cinnamic acid, p-chlorocinnarnic acid and p-methylcinnamic acid were prepared by crystallization from the solutions of both components. All the crystals belonged to typical chiral space group P212121. The crystal chirality is generated through the formation of a unidirectional twofold helix between the two components through quaternary ammonium salt interaction and hydrogen bonding in the lattice. This kind of spontaneous crystallization necessarily gives crystals of both clockwise and counterclockwise helicites. Here, pseudo-seeding based on utilizing these crystals as seed crystals was examined, resulting in successful helicity control in crystallization from solutions of tryptamine and different carboxylic acids. 相似文献