Synthesis, structure, and reactivity of two-coordinate mercury alkyl compounds with sulfur ligands: relevance to mercury detoxification.
Synthesis, structure, and reactivity of two-coordinate mercury alkyl compounds with sulfur ligands: relevance to mercury detoxification.
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具有硫配体的二配位汞烷基化合物的合成、结构和反应性：与汞解毒的相关性。
DOI：
10.1021/ic900721g
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发表时间：
2009
影响因子：
4.6
通讯作者：
Parkin,Gerard
中科院分区：
文献类型：
--
作者：
Melnick,JonathanG;Yurkerwich,Kevin;Parkin,Gerard
X−Hg−R 型二配位汞烷基化合物（其中 X 是单齿硫供体）对质子裂解的敏感性已得到研究，作为持续努力的一部分，以获得与了解有机汞裂解酶 MerB 作用机制相关的信息。具体来说，研究了二配位汞烷基化合物PhSHgR、[mimBut]HgR和{[HmimBut]HgR}+(HmimBut=2-巯基-1-叔丁基咪唑；R=Me，Et)对PhSH的反应性，从而证明裂解Hg-C键的能力很大程度上取决于系统的性质。例如，PhSHgMe 与 PhSH 的反应需要在 145 °C 下加热数周才能释放 CH4，而 PhSHgEt 与 PhSH 的类似反应会在 100 °C 下 2 天内产生 C2H6。此外，HmimBut 还促进 PhSH 对 Hg−C 键的质子裂解。例如，虽然 {[HmimBut]HgEt}+ 与 PhSH 的反应在高温下消除了 C2H6，但在 HmimBut 存在下，质子裂解在室温下发生了 2 天。 HmimButto 促进质子裂解的能力可以解释为更高配位物种 {[HmimBut]nHgR}+ 的形成，该物种比二配位 {[HmimBut]HgR}+ 更容易受到 Hg−C 键裂解的影响。这些观察结果支持这样的观点，即获得配位数大于二的物种对于 MerB 的有效活动至关重要。
The susceptibility of two-coordinate mercury alkyl compounds of the type X−Hg−R (where X is a monodentate sulfur donor) towards protolytic cleavage has been investigated as part of ongoing efforts to obtain information relevant to understanding the mechanism of action of the organomercurial lyase,MerB. Specifically, the reactivity of the two-coordinate mercury alkyl compounds PhSHgR, [mimBut]HgR and {[HmimBut]HgR}+(HmimBut= 2-mercapto-1-t-butylimidazole; R = Me, Et) towards PhSH was investigated, thereby demonstrating that the ability to cleave the Hg−C bond is very dependent on the nature of the system. For example, whereas the reaction of PhSHgMe with PhSH requires heating at 145 °C for several weeks to liberate CH4, the analogous reaction of PhSHgEt with PhSH leads to evolution of C2H6over the course of 2 days at 100 °C. Furthermore, protolytic cleavage of the Hg−C bond by PhSH is promoted by HmimBut. For example, whereas the reaction of {[HmimBut]HgEt}+with PhSH eliminates C2H6at elevated temperatures, the protolytic cleavage occurs over a period of 2 days at room temperature in the presence of HmimBut. The ability of HmimButto promote the protolytic cleavage is interpreted in terms of the formation of a higher coordinate species {[HmimBut]nHgR}+that is more susceptible to Hg−C bond cleavage than is two-coordinate {[HmimBut]HgR}+. These observations support the notion that access to a species with a coordination number greater than two is essential for efficient activity ofMerB.