Misheer Natasha, Ndungu Patrick G, Pretorius Jan A
The Department of Chemistry, University of Pretoria. Private Bag X20, Hatfield, Zip Code 0028, South Africa.
ESKOM Research and Innovation Centre, Rosherville, Private Bag 40157, Cleveland, Johannesburg, 2022, South Africa.
Heliyon. 2024 Oct 5;10(20):e38796. doi: 10.1016/j.heliyon.2024.e38796. eCollection 2024 Oct 30.
This paper describes a group of sixty (60) sub and extended chlorine oxide species with the general formulae of ClO (with x ≤ 2, y ≤ 8). Their role in water treatment cycles, behaving as key reactive species, is represented by a complex sequence of chemical inter-dependencies, exposed as a cohesive set of chemical reactions to demonstrate their cyclic role in aqueous media. An empirical/semi-empirical computational approach, supported by Ab Initio simulations, in accordance with open-shell character, has been followed to determine their optimum molecular geometries, to obtain their thermochemical properties. Besides a single molecular analysis, Grand Canonical Ensemble simulations, supported by a revised library of force field parameters, constituted a core component of the computational approach and proved to be invaluable in confirming thermochemical properties. This approach also offered finite estimates of optimum model sizes, a benefit with wider modelling application. Extended molecular species of ClO display a complex sequence of bonding character, with a variable charge dissipation (reported as partial charges), which complicates selection of basis sets in optimizing molecular geometries, during Ab Initio analyses. Optimum molecular geometries were obtained using Gaussian and MOPAC, which in turn resulted in reliable Heats of Formation. These correlated well with energies extracted from the open literature. Thermodynamic Analysis of the reaction of selected chlorine oxides with water using FactSage, predicted the production of known and two previously undetected chlorine species, [ClO] and [ClOH].
本文描述了一组60种亚氯氧化物和扩展氯氧化物，其通式为ClOₓ（x≤2，y≤8）。它们在水处理循环中作为关键反应物种的作用，由一系列复杂的化学相互依存关系表示，这些关系以一组连贯的化学反应呈现，以展示它们在水介质中的循环作用。遵循了一种经验/半经验计算方法，并辅以从头算模拟，根据开壳特性来确定它们的最佳分子几何结构，以获得它们的热化学性质。除了单分子分析外，由修订的力场参数库支持的巨正则系综模拟构成了计算方法的核心组成部分，并被证明在确认热化学性质方面非常宝贵。这种方法还提供了对最佳模型大小的有限估计，这对更广泛的建模应用有益。ClO的扩展分子物种表现出复杂的键合特征序列，具有可变的电荷耗散（报告为部分电荷），这使得在从头算分析中优化分子几何结构时基组的选择变得复杂。使用高斯和MOPAC获得了最佳分子几何结构，进而得到了可靠的生成热。这些与从公开文献中提取的能量相关性良好。使用FactSage对选定的氯氧化物与水的反应进行热力学分析，预测了已知的和两种以前未检测到的氯物种[ClO]和[ClOH]的产生。
