School of Civil Engineering & Geosciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, United Kingdom.
Environ Sci Technol. 2012 Aug 7;46(15):8131-9. doi: 10.1021/es301165p. Epub 2012 Jul 10.
Chlordecone (C(10)Cl(10)O; CAS number 143-50-0) has been used extensively as an organochlorine insecticide but is nowadays banned under The Stockholm Convention on Persistent Organic Pollutants (POPs). A search for chlordecone-respiring organisms and choosing between reductive versus oxidative remediation tools and strategies to clean up chlordecone-polluted environments would benefit from the availability of Gibbs free energy data of chlordecone and its potential dechlorination products. Presently such data are not available. Polycyclic "cage" molecules of which chlordecone is an example contain considerable strain energy. It is not a priori clear how this affects the thermodynamic properties of the chlorinated members of this unique class of compounds and to what extent redox potentials for the halogenated congeners are different from those of other aliphatic and aromatic organohalogens. We performed ab initio quantum chemical calculations to estimate Δ(f)H(m)° and Δ(f)G(m)° values of chlordecone and selected dechlorination products and used these data to calculate their Gibbs free energy and redox potential. With redox potentials in the range of 336-413 mV chlordecone has an E(o)' value similar to that of other organochlorines. The results indicate that there are no thermodynamic reasons why chlordecone-respiring or -fermenting organisms should not exist.
氯丹（C(10)Cl(10)O；CAS 号 143-50-0）曾被广泛用作有机氯杀虫剂，但如今已根据《关于持久性有机污染物的斯德哥尔摩公约》被禁用。为了寻找能够分解氯丹的微生物，并在还原型和氧化型修复工具之间进行选择，以便对氯丹污染的环境进行清理，我们需要氯丹及其潜在脱氯产物的吉布斯自由能数据。目前，这些数据并不存在。多环“笼状”分子，如氯丹，就含有相当大的应变能。这并不清楚这将如何影响这一独特化合物类别的氯化成员的热力学性质，以及卤化同系物的氧化还原电位与其他脂肪族和芳香族有机卤化物的电位有多大差异。我们进行了从头算量子化学计算，以估算氯丹和选定脱氯产物的Δ(f)H(m)°和Δ(f)G(m)°值，并使用这些数据计算它们的吉布斯自由能和氧化还原电位。氯丹的氧化还原电位在 336-413 mV 之间，其 E(o)'值与其他有机氯杀虫剂相似。结果表明，没有热力学原因可以说明不存在能够分解或发酵氯丹的微生物。
