简易型离子选择电极-流动注射分析仪的研制及卤水中氯、溴和碘的连续测定

本文设计研制了简单实用的流通池,组装了简易型离子选择电极—流动注射分析仪,对体系的分析特点和影响因素进行了考察。此装置性能可靠,能满足简单流注分析的需要,并建立了卤水中Cl~-、Br~-和I~-的连续测定方法。     

一锅法制备全乙酰吡喃溴代糖

将未保护的吡喃糖与醋酸酐在分子碘的催化下制得全乙酰吡喃糖 ,随后不经分离直接与溴化氢的冰醋酸溶液( 4 5 %)反应得到全乙酰吡喃溴代糖 .这种一锅法制备全乙酰吡喃溴代糖操作方便 ,收率高 ,经济实用且对环境友好     

A novel and direct synthesis of chroman derivatives using a hypervalent iodine(III) reagent

The direct aromatic carbon-oxygen bond-formation reaction was described and the novel and simple synthetic method for chroman derivatives involving aromatic cation radical intermediates was developed using the hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA).     

Direct measurements of HOx radicals in the marine boundary layer: testing the current tropospheric chemistry mechanism

OH and HO(2) radicals, atmospheric detergents, and the reservoir thereof, play central roles in tropospheric chemistry. In spite of their importance, we had no choice but to trust their concentrations predicted by modeling studies based on known chemical processes. However, recent direct measurements of these radicals have enabled us to test and revise our knowledge of the processes by comparing the predicted and observed values of the radical concentrations. We developed a laser-induced fluorescence (LIF) instrument and successfully observed OH and HO(2) at three remote islands of Japan (Oki Island, Okinawa Island, and Rishiri Island). At Okinawa Island, the observed daytime level of HO(2) agreed closely with the model estimates, suggesting that the photochemistry at Okinawa is well described by the current chemistry mechanism. At Rishiri Island, in contrast, the observed daytime level of HO(2) was consistently much lower than the calculated values. We proposed that iodine chemistry, usually not incorporated into the mechanism, is at least partly responsible for the discrepancy in the results. At night, HO(2) was detected at levels greater than 1 pptv at all three islands, suggesting the presence of processes in the dark that produce radicals. We showed that ozone reactions with unsaturated hydrocarbons, including monoterpenes, could significantly contribute to radical production.     

Synthesis of 3-arylisocoumarins, including thunberginols A and B, unsymmetrical 3,4-disubstituted isocoumarins, and 3-ylidenephthalides via iodolactonization of methyl 2-ynylbenzoates or the corresponding carboxylic acids

3-Aryl-4-iodoisocoumarins, which were readily and efficiently prepared by regioselective iodolactonization of methyl 2-ynylbenzoates or the corresponding carboxylic acids, were used as precursors either to 3-arylisocoumarins, including naturally-occurring thunberginols A and B, or to unsymmetrical 3,4-disubstituted isocoumarins. On the other hand, (Z)- and (E)-3-iodomethylidenephthalides, which were regioselectively prepared by iodolactonization of methyl 2-ethynylbenzoate, were employed as starting materials for the stereospecific synthesis of (Z)- and (E)-3-ylidenephthalides, respectively. Some 3-arylisocoumarins and unsymmetrical 3,4-disubstituted isocoumarins showed certain cytotoxic activity against human cancer cell lines in vitro.     

Facile oxidative conversion of alcohols to esters using molecular iodine

A simple, efficient, and high-yield procedure for the oxidative conversion of alcohols to various types of esters and ketones, with molecular iodine and potassium carbonate was successfully carried out.     

Natural zeolitic material of the clinoptilolite type doped with iodine and its ions

The aim of this study was the preparation of natural zeolitic materials doped with iodine and its ions. Natural zeolite from an East Slovakian deposit was used. The content of iodine in the zeolitic products depended on the experimental conditions used for the preparation. The products and their intermediates obtained at 100, 200, 400 and 900°C were identified.     

Molecular and crystal structure of nido-9-C5H5N-11-I-7, 8-C2B9H10: Supramolecular architecture based on hydrogen bonds X-H⋯I (X = B, C)

A single crystal X-ray diffraction study of a new iodine-containing cluster compound 9-(pyridine)-11-iodo-decahydro-7,8-dicarba-nido-undecaborane [9-C₅H₅N-11-I-7,8-C₂B₉H₁₀] has been performed. Crystal data: C₇H₁₅B₉NI, M = 337.39, monoclinic, space group P2₁/c, unit cell parameters: a = 9.348(1) Å, b = 11.159(1) Å, c = 13.442(2) Å, β = 98.13(1)°, V = 1388.1(5) ų, Z = 4, d _calc = 1.614 g/cm³, T = 295 K, F(000) = 648, μ = 2.276 mm^?1. The structure was solved by a direct method and refined in the full-matrix anisotropic approximation (isotropic for hydrogen atoms) to final agreement factors R ₁ = 0.0254, wR ₂ = 0.0454 for 2437 I _hkl ≥ 2σ_I from 3590 measured I _hkl (an Enraf-Nonius CAD-4 diffractometer, λMoK _α , graphite monochromator, θ/2θ-scanning). The molecules are joined into a supramolecular assembly by hydrogen bonds X-H?I (X = B, C).     

Encapsulating property of ap-t-butylcalix[6]arene derivative: Formation of charge-transfer complexes of alkadienes with iodine in the presence of octopus-type calix[6]arene

This paper deals with the ability ofp-tert-butylcalix[6]arene derivative1, which has six 3,6,9-trioxadecyl substituents at the phenolic oxygens, to encapsulate CT complexes of alkadienes with iodine. By adding I₂ to alkadienes in CH₂Cl₂ in the presence of1, the absorbance at 363 nm, which was ascribed to I ₃ ^– ion, increased in the order: 1,5-hexadiene<1,9-decadiene 1,7-octadiene. The reactivity features of the CT complexes in the presence of1 are discussed.