Generation of H2S from Thiol-Dependent NO Reactivity of Model [4Fe-4S] Cluster and Roussin’s Black Anion

作者：Kady Oakley, Ziyi Zhao, Ryan L. Lehane, Ji Ma, Eunsuk Kim · 发表于：Inorganic Chemistry · 年份：2021 · DOI：10.1021/acs.inorgchem.1c01328 · 被引用次数：12 · 研究领域：Sulfur Compounds in Biology、Industrial Gas Emission Control、Nitric Oxide and Endothelin Effects

Iron–sulfur clusters (Fe–S) have been well established as a target for nitric oxide (NO) in biological systems. Complementary to protein-bound studies, synthetic models have provided a platform to study what iron nitrosylated products and byproducts are produced depending on a controlled reaction environment. We have previously shown a model [2Fe-2S] system that produced a dinitrosyl iron complex (DNIC) upon nitrosylation along with hydrogen sulfide (H 2 S), another important gasotransmitter, in the presence of thiol, and hypothesized a similar reactivity pattern with [4Fe-4S] clusters which have largely produced inconsistent reaction products across biological and synthetic systems. Roussin’s black anion (RBA), [Fe 4 (μ 3 -S) 3 (NO) 7 ] −, is a previously established reaction product from synthetic [4Fe-4S] clusters with NO. Here, we present a new reactivity for the nitrosylation of a synthetic [4Fe-4S] cluster in the presence of thiol and thiolate. [Et 4 N] 2 [Fe 4 S 4 (SPh) 4 ] ( 1 ) was nitrosylated in the presence of excess PhSH to generate H 2 S and an “RBA-like” intermediate that when further reacted with [NEt 4 ][SPh] produced a {Fe(NO) 2 } 9 DNIC, [Et 4 N][Fe(NO) 2 (SPh) 2 ] ( 2 ). This “RBA-like” intermediate proved difficult to isolate but shares striking similarities to RBA in the presence of thiol based on IR υ (NO) stretching frequencies. Surprisingly, the same reaction products were produced when the reaction started with RBA and thiol. Similar to 1 /NO, RBA in...