Construction of Pseudorotaxanes and Rotaxanes Based on Cucurbit[n]uril

¹H-NMR spectroscopic analysis indicates that cucurbit[7]uril can form a stable inclusion complex with 1,6-hexanediamine, while cucurbit[5]uril cannot form pseudorotaxane with 1,6-hexanediamine under our experimental conditions. This was confirmed by the crystal structure of the complex. The cavity of cucurbit[8]uril seems to be large for binding 1,6-hexanediamine efficiently. And a simple, mild, high-yield (>80%) method has been described for the synthesis of rotaxanes through the self-assembly of pseudorotaxanes of cucurbit[n]uril (n=6, 7)/1, 6-hexanediamine and sodium tetraphenylborate. The obtained rotaxanes are held intact solely by noncovalent interactions, and are characterized by elemental analysis, ¹H-NMR, ESI-MS and MALDI-TOF MS.     

Synthesis and Cation-Binding Properties of Novel p-Isopropenylcalix[n]arenes and Their Acetylated Derivatives

A novel two-step method was developed to prepare individual p-isopropenylcalix[n]arenes [n=4, 6, 8]. In the first step, linear phenolic oligomers were prepared in a basic medium from p-isopropenylphenol and paraformaldehyde. The second step, cyclization of the linear oligomers was carried out at higher temperatures. Ethylene glycol was used as medium, and sodium tetraborate-decahydrate as the catalyst. O-Acetylated derivatives were obtained by acetylation of the phenolic hydroxyl groups of p-isopropenylcalix[n]arenes [n=4, 6, 8]. The p-isopropenyl-calix[n]arenes and their acetylated derivatives were characterized by IR, ¹H NMR and UV spectroscopy, and elemental analysis. Their ability to extract metal cations from aqueous solutions was evaluated via metal picrate extraction experiments. A parallel investigation of the cation-binding ability of the p-tert-butylcalix[n]arenes [n=4, 6, 8] and their acetylated derivatives was also performed. The p-isopropenylcalix[6]arene hexaacetate is the most effective extracting agent for metal picrates, and shows strong affinity towards Rb cation.     

六～八元瓜环与咪唑[4,5-f]-1',10'-菲咯啉衍生物的相互作用

合成了2-苯基-咪唑[4,5-f]-1',10'-菲咯啉和对二甲氨基-2-苯基-咪唑[4,5-f]-1',10'-菲咯啉两种咪唑[4,5-f]-1',10'-菲咯啉衍生物, 并经过一、二维核磁共振谱以及质谱方法的验证. 利用¹H NMR、质谱以及紫外可见分光光度法, 考察了以六～八元瓜环为主体, 咪唑[4,5-f]-1',10'-菲咯啉衍生物为客体的作用体系, 以及形成的主客体包结配合物的结构特征. 研究结果表明: 三种瓜环均与2-苯基-咪唑[4,5-f]-1',10'-菲咯啉发生相互作用, 客体以较小的苯基一端穿过瓜环内腔直至苯基部分和菲咯啉部分分别露置在瓜环的两个端口外, 特别是八元瓜环能容纳两个客体分子. 而对二甲氨基-2-苯基-咪唑[4,5-f]-1',10'-菲咯啉仅能与七及八元瓜环相互作用, 作用模式与前者相同.     

Thermodynamic and electrochemical aspects ofp-tert-butylcalix[n]arenes (n=4, 6, 8) and their interactions with amines

Attention is drawn to the need of detailed thermodynamics in calixarene chemistry. The reasons for increasing efforts in this area are underlined and suggestions for new issues to be addressed are given. The solution thermodynamics ofp-tert-butylcalix[n]arenes (n=4, 6, 8) is discussed with particular reference to transfer Gibbs energies which reflect the selective solvation that the tetramer and the octamer undergo in the various solvents. This is followed by recent solution studies on amine-p-tert-butylcalix[n]arene (n=4, 6, 8) in nitrobenzene and in benzonitrile at 298.15 K which indicate the lower acidic character of the tetramer relative to the hexamer and the octamer in these solvents. As an implication of these results, very low conductivities are observed in studies involving the interaction of the former with amines. Thus, thermodynamic studies suggest thatp-tert-butylcalix[4]arene interacts with triethylamine in benzonitrile and in nitrobenzene through hydrogen bonding or ion-pair formation. A thermodynamic cycle is used to investigate the effect associated with the interaction of the amine with the tetramer in these solvents.This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes.     

Synthesis and metal complexation studies of [2n]thiacalix[m]arene[m]pyrazine

Novel [2_n]thiacalixarenepyrazine and [2_n]thiacalixarenetriazine systems were synthesised by one-pot S_NAr reactions. A screening of the metal-complexing ability of [2₆]hexathiacalix[3]arene[3]pyrazine revealed its affinity for Cu^I, Cu^II and Ag^I metal salts.     

A Quantitative Spectrometric Assay for the Determination of Solution Concentration of para-sulphonato-calix[n]arenes and Their Derivatives

A spectrometric assay for the determination of concentration of para-sulphonato-calix[n]arenes and their derivatives has been developed using dimethylmethylene blue (DMMB) as a probe. Interaction with para-sulphonato-calix[n]arenes leads to a metachromatic shift in the spectrum of DMMB with appearance of a peak at 536 nm and diminution of the spectral intensity of the peaks at 594 and 649 nm. The method shows good linearity in the concentration range 0–6 μg/ml for para-sulphonato-calix[n]arenes. in final form: 27 December 2004     

Theoretical studies of [n]paracyclophanes and their valence isomers

Summary The valence isomerisations of benzene, [6]- and [7]paracyclophane to their Dewar benzene and prismane isomers are studied with the MNDO method using the unrestricted Hartree-Fock (UHF) and the configuration interaction (C.I.) approximations. The enthalpy of the reaction Dewar benzene benzene is H° _r =–68.9 kcal/mol and the activation enthalpy is H°=27.9 kcal/mol (with C.I.). The reaction path hasC _2v symmetry.The determination of several points of the lowest potential energy surface of [6]- and [7]paracyclophanes leads to a minimum reaction path having the same topology as for the potential energy surface of the nonbridged benzene. The only difference is a quantitative change in the energy values of the aromatic isomers due to the deformation introduced by the alkyl chain. For [6]paracyclophane, the activation enthalpy is H°=24.6 kcal/mol and the activation entropy is S ⁰=0.6 cal K^–1 mol^–1 calculated with C.I.The enthalpy of the reaction prismane Dewar benzene is H° _r –32 kcal/mol and the activation enthalpy is H°19 kcal/mol. The highest molecular symmetry group common to both molecules isC _2v , whereas the symmetry group of the reaction path is lowered toC _s . Along this reaction path is located a biradicaloid intermediate, separated by low activation barriers from the products. No significant changes of the potential energy surfaces are found for the bridged [n]prismanes and the [n]Dewar benzenes.All the calculated values, reaction enthalpies, activation enthalpies and entropies, are in a good agreement with literature experimental data.This article is dedicated to Professor A. Pullman     

Benzo[b]tellurophene, Dibenzo[b,d]tellurophene, and Their Derivatives. (Review)

Data on the synthesis, reactions, crystal structure, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]tellurophene, and their derivatives are reviewed and analyzed.     

Condensed Pyridine Bases. Synthesis and Reactions of Benzofuro[2,3-c]indeno[2,1-e]-, Benzothieno[2,3-c]Indeno[2,1-e]-, Benzofuro-[3,2-c]Indeno[2,1-e]- and Thieno[2,3:4′,5′]-thieno[3,2-c]indeno[2,1-e]pyridines

Condensation of hetarene carboxaldehydes with phthalide gave 2-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 2-(3-hydroxy-1-oxoinden-2-yl)-5-ethylthieno[2,3-b]thiophene. Starting from hetaryl acetic acids gave 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]thiophene. Acylation of 3-hydroxy-1-oxoinden-2-yl-substituted heterocycles using acetic anhydride in the presence of 70% HClO₄ leads to the formation of pentacyclic pyrilium salts. Pentacyclic indenopyridines are prepared by treating the pyrilium salts with ammonia. The reaction of the carbonyl group in the indenopyridines with hydroxylamine, hydrazine hydrate, and in reduction using NaBH₄ has been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 435–443, March, 2005.     

二氯化二(N-甲基-N′-苄基-乙二胺)(二水)合镍的合成及其与瓜环相互作用的研究

以氯化镍与N-甲基-N′-苄基-乙二胺(NMEA)反应合成了配合物二氯化二(N-甲基-N′-苄基-乙二胺)二水合镍([Ni(NMEA)₂·(H₂O)₂]·Cl₂)。利用元素分析、IR光谱、NMR对其结构进行了表征。通过1H NMR和UV-Vis光谱研究了该配合物与六、七、八元瓜环的相互作用，并且考察了其动力学行为。结果表明六、七元瓜环与配合物能形成物质的量比为2∶1的超分子结构，而八元环与配合物的作用则具有不同的模式。     

Synthesis of 3-alkyl-1,4-dihydrocyclopenta[b]indoles: unexpected formation of dimeric compounds

Acid-catalyzed dehydration of 3-alkyl(aryl)-4-methyl-1,2,3,4-tetrahydrocyclopenta[b]indol-3-ols gives dimeric derivatives of 3-alkyl(aryl)-4-methyl-1,4-dihydrocyclopenta[b]indole.     

一类新型环型笼状化合物 瓜环：(Ⅱ)酸度、IA、IIA金属离子对瓜环溶解性的影响

The experimental results reveal that solubility of cucurbit[n=5～8]urils is related with acidity of solution and metal ions. In hydrochloric acid， cucurbit[7]uril is the most soluble one， and cucurbit[8]uril is the least soluble one. There is no significant influence of alkaline metal ion on the solubility of cucurbiturils. The solubility of cu-curbit[7]uril increases greatly in a SrCl₂ solution. However， increase of weight of cucurbit[n=5～8]urils suggest that cucurbit[n]urils can catch Ba²⁺ in a solution.     

Theoretical calculations of95Mo-NMR chemical shifts for compounds [MoO4−n S n ]2−

Summary Theoretical calculation of⁹⁵Mo-NMR chemical shifts for [MoO_4–n S _n ]^2– (n=0–4) compounds is reported here for the first time on the basis of Fenske-Hall method and Sum-Over-State (SOS) perturbation theory. A systematic decrease in shielding of⁹⁵Mo nuclei with increase of number of sulfur in [MoO_4–n S _n ]^2–, which is observed experimentally, can be reasonably explained by our calculation. A good linear relationship between chemical shifts of calculation and experiment is obtained. The electronic structure and bonding in these compounds are also discussed.Supported by Nature Science Foundation of China     

在平面构型[PdnClm]2-阴离子驱动下三种瓜环基超分子框架化合物的构筑

采用无机阴离子诱导方法,以具有平面构型的[Pd_nCl_m]~(2-)阴离子为结构导向试剂,成功制备了3种具有框架结构特征的瓜环基超分子化合物:{Na_2(H_2O)_6TMeQ[6]}[Pd_2Cl_6]·3H_2O (1)、(H_3O)_2{CyH_5Q[5]}[Pd_2Cl_6]·3H_2O (2)及(H_3O)_2{Q[5]}[PdCl_4]·23H_2O (3)。X射线单晶衍射的结果表明:在1中,Na+离子与TMeQ[6]端口羰基氧直接配位形成一维结构的超分子链,在[Pd_2Cl_6]~(2-)阴离子与TMeQ[6]的外壁作用下,进一步构筑形成三维的框架结构;在2中,在[Pd_2Cl_6]~(2-)阴离子与CyH_5Q[5]的外壁作用下,CyH_5Q[5]以一维链有序排列,且4条CyH_5Q[5]分子链可堆砌成一孔道,孔道中填充了[Pd_2Cl_6]~(2-)阴离子,最终形成三维框架结构;在3中,8个[PdCl_4]~(2-)阴离子与4个Q[5]分子通过瓜环外壁相互作用,形成二维层状框架结构,层与层之间再通过非共价键作用力,最终形成三维层状框架结构。在这3种瓜环基超分子框架化合物中,[Pd_nCl_m]~(2-)阴离子促进了瓜环分子有序化排列,形成了具有框架结构特征的自组装体。这种主要驱动力来源于瓜环的外壁作用,即瓜环"正电性外壁"与[Pd_nCl_m]~(2-)阴离子间的离子偶极作用。     

Synthesis of hexahydroazonino[5,6-b]indoles from hexahydroazepino[4,3-b]-and-[3,4-b]indoles and activated alkynes

A reaction of substituted hexahydroazepino[4,3-b]-and-[3,4-b]indoles with activated alkynes was studied. A one-step method for the synthesis of isomeric hexahydroazonino[5,6-b]indoles different by positions of the double bond in the azonine ring was developed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2244–2250, November, 2007.     

四个CyB5Q[5]-Ca配合物的晶体结构和在不同阴离子环境下的不同配位状态

在不同阴离子介质中,利用瓜环家族新成员CyB₅Q[5]与钙离子生成了4个CyB₅Q[5]-Ca配合物（1~4）,用X射线单晶衍射确定了它们的结构。晶体结构表明,在Cl^-、[ZnCl₄]^2-、[ZnCl₄]^2-+ClO₄^-和ClO₄^-环境下,分别生成了不同配位类型的配合物。     

An Absence of Non-specific Immune Response towards para-Sulphonato-calix[n]arenes

The effects of para-Sulphonato-calix[4]arene, para-Sulphonato-calix[6]arene and para-Sulphonato-calix[8]arene on the activation of NADPH oxidase in neutrophils has been studied. All three molecules do not induce NADPH oxidase activation, and hence do not stimulate neutrophils. Measurement of cell viability demonstrates that these three water-soluble calix[n]arene derivatives are not cytotoxic.