O2(1Δ) Yield Measurement by Raman Spectroscopy With Elimination of Chlorine Fluorescence Interference

Deleterious chlorine fluorescence was found to occur at the same frequency as the Raman scattering of O₂(1Δ) and O2(³∑), seriously affecting the O₂(1Δ) yield measurement in the re-action of chlorine with basic hydrogen peroxide by use of the Raman spectroscopy technique. To solve this problem we have taken advantage of the fact that Raman radiation is always strongly polarized while fluorescence is essentially non-polarized in a gaseous medium. When chlorine utilization of a singlet oxygen generator is 88%, O₂(1Δ) yield reaches (42.4±7.4)% with the effect of chlorine fluorescence completely eliminated.     

CIONO2与O(3P)的反应机理

采用密度泛函方法Ｂ３ＬＹＰ／６－３１Ｇ＾＊研究了反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→ＣｌＯ＋ＮＯ３反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→Ｏ２＋ＣｌＯＮＯ的反应机。该结果与大部分实验者的推论是一致的,对于后一反应,其两种反应途径的活化势垒较为相近,表明两种反应途径均是可能的。     

Über die Gasphasenstruktur von CF3NCl2 und die Darstellung von CF3NCl2F+MF6− (M = As,Sb) und CF2 = NClF+SbF6−

Gas Phase Structure of CF₃NCl₂ and Preparation of CF₃NCl₂F⁺MF₆^? (M = As, Sb) and CF₂ = NCl₂F⁺SbF₆^? The gas phase structure of CF₃NCl₂ is reported. The following skeletal parameters are derived (r_a-values, error limits are 3σ values): N? C = 1.470(6) Å, N? Cl = 1.733(3) Å, ClNCl = 111.5(4)° and ClNC = 107.6(5)°. CF₃NCl₂F⁺MF₆^? is prepared by fluorination of CF₃NCl₂ with XeF⁺MF₆^?. The same educt CF₃NCl₂ reacts with XeF⁺SbF₆^? at ?40°C to CF₂ = NClF⁺SbF₆^? under elimination of ClF.     

示波滴定法在环境监测中的应用——水中溶解氧、氯、钙及镁的测定

本文运用示波滴定法定于水中对溶解氧、Ca~(2+)、Mg~(2+)及Cl~-离子进行测定。利用示波器观察荧光点的移动或示波极谱图切口的产生指示滴定终点。方法简便、灵敏、符合定量分析要求。可用于环境监测之中。     

Excimer laser projection etching of copper foils in chlorine gas

Low-fluence XeCl laser etching of copper foils in a chlorine environment has been studied. The etch rate is fluence-dependent in the range 0.05–1.0 J cm^?2 and is governed by the growth characteristics of the chloride layer formed in the interpulse period. Projection etching with good pattern reproduction and resolution for high-aspect-ratio features is demonstrated.     

Electrochemical Determination of a Free Chlorine Residual Using Cathodic Potential‐Step Chronocoulometry

The cathodic reaction of chlorine residual (CR) combined with anodic pre‐electrolysis enables the quantification of CR as a gaseous chlorine. Potential‐step chronocoulometry was successfully applied to extend the CR detection range.     

Alternative spectrophotometric method for standardization of chlorite aqueous solutions

The chlorite ion is the principal by-product of the treatment of drinking water by chlorine dioxide. In function of the chlorite salt instability, standard solutions of this ion need standardization by iodometric titration, which is a reliable method although labor intensive and time consuming. An alternative method to standardization of aqueous chlorite solutions, based on its direct UV absorption measurement, was presented. Besides the maximum absorption (260 nm) generally used in other studies, the minimum (239 nm) and isosbestic (248 nm) wavelengths were proposed as supplementary points to chlorite quantification and their molar absorptivity coefficients were estimated (155.2 ± 0.6, 104.5 ± 1.0 and 69.0 ± 1.2 L cm⁻¹ mol⁻¹, respectively). The direct spectrophotometric determination of chlorite could be made selectively even in the presence of high concentration of major contaminants (chorine dioxide, chloride and chlorate), being a simple and rapid method, consuming very low volume of sample and generating low quantities of laboratory wastes.     

A review on the electrochemical production of chlorine dioxide from chlorates and hydrogen peroxide

Chlorine dioxide is one of the most interesting oxidants because it combines a strong capacity of oxidation with low formation of hazardous byproducts such as chlorinated organics during its application. Because of that, it is widely used in disinfection of drinking water and, currently, it is aimed to be used in the disinfection of surfaces or buildings. Although it is usually produced by the chemical interaction of chlorite with hypochlorite/chlorine or hydrochloric acid, one interesting alternative for its production is the combination in strongly acidic media of chlorate and hydrogen peroxide. Both compounds are known to be efficiently manufactured with electrochemical technology, opening the possibility of a complete electrochemical process to produce this important oxidant. This review summarizes the recent progress in the electrochemical production of the two raw materials, as well as the complete electrochemical production of chlorine dioxide, not only paying attention to the scientific literature but, most importantly, to recent patents, trying to see in which technology readiness level are each of the technologies and what are the elements of the value chain required for a complete implementation of the technology.     

The rotational spectrum of chlorine nitrate (ClONO2) in the four lowest nν9 polyads

The analysis of the recently recorded 78-378 GHz broadband spectrum of ClONO₂ has been extended to cover rotational transitions in all 14 excited vibrational states up to 650 cm⁻¹ above the ground state. We report new measurements and analysis of the 2ν₉ and 3ν₉ dyads, and first assignment and analysis for the 4ν₉ and 5ν₉ triads. The polyad fits encompass a total of over 20 000 newly measured transition frequencies and spectroscopic constants are reported for 10 vibrationally excited states in each of ³⁵ClONO₂ and ³⁷ClONO₂. All polyads were fitted with a new coupling scheme between the perturbing states combining c-axis Coriolis and Fermi interactions. The scheme is validated by multiple tests of the physical significance of the derived parameters and it results in improved deviations of fits and significant reduction in the number of adjustable parameters.