C S Akshaya Keerthi, Das Sandip, Bhardwaj Prabhakar, Sk Md Palashuddin, Kumar Pankaj
Department of Chemistry, Indian Institute of Science Education and Research (IISER), Tirupati 517507, India.
Department of Chemistry, Aligarh Muslim University (AMU) Aligarh, Uttar Pradesh 202001, India.
Dalton Trans. 2023 Nov 14;52(44):16492-16499. doi: 10.1039/d3dt03177b.
Here, we report the nitric oxide oxygenation (NOO) reactions of two distinct metal nitrosyls {Co-nitrosyl ( = 0) . Cr-nitrosyl ( = 1/2)}. In this regard, we synthesized and characterized [(BPMEN)Co(NO)] ({CoNO}, 1) to compare its NOO reaction with that of [(BPMEN)Cr(NO)(Cl)] ({CrNO}, 2), having a similar ligand framework. Kinetic measurements showed that {CrNO} is thermally more stable than {CoNO}. Complexes 1 and 2, upon reaction with the superoxide anion (O˙), generate [(BPMEN)Co(NO)] (Co-NO, 3) and [(BPMEN)Cr(NO)Cl] (Cr-NO, 4), respectively, with O evolution. Furthermore, analysis of these NOO reactions and tracking of the N-atom using N-labeled NO (NO) revealed that the N-atoms of 3 (Co-NO) and 4 (Cr-NO) derive from the nitrosyl (NO) moieties of 1 and 2, respectively. This work represents a comparative study of oxidation reactions of {CoNO} {CrNO}, showing different rates of the NOO reactions due to different thermal stability. To complete the NOM cycle, we reacted 3 and 4 with NO, and surprisingly, only 3 generated {CoNO} species, while 4 was unreactive towards NO. Furthermore, the phenol ring nitration test, performed using 2,4-di--butylphenol (2,4-DTBP), suggested the presence of a proposed peroxynitrite (PN) intermediate in the NOO reactions of 1 and 2.
在此，我们报告了两种不同的金属亚硝酰基化合物{钴亚硝酰基（= 0）. 铬亚硝酰基（= 1/2）}的一氧化氮氧化（NOO）反应。在这方面，我们合成并表征了[(BPMEN)Co(NO)]（{CoNO}，1），以将其NOO反应与具有相似配体框架的[(BPMEN)Cr(NO)(Cl)]（{CrNO}，2）的NOO反应进行比较。动力学测量表明，{CrNO}在热稳定性上比{CoNO}更高。配合物1和2与超氧阴离子（O˙）反应时，分别生成[(BPMEN)Co(NO)]（Co - NO，3）和[(BPMEN)Cr(NO)Cl]（Cr - NO，4），并伴有氧气释放。此外，对这些NOO反应的分析以及使用N标记的NO（NO）对N原子的追踪表明，3（Co - NO）和4（Cr - NO）的N原子分别源自1和2的亚硝酰基（NO）部分。这项工作代表了对{CoNO} {CrNO}氧化反应的比较研究，显示出由于热稳定性不同导致NOO反应速率不同。为了完成NOM循环，我们使3和4与NO反应，令人惊讶的是，只有3生成了{CoNO}物种，而4对NO无反应。此外，使用2,4 - 二叔丁基苯酚（2,4 - DTBP）进行的苯酚环硝化试验表明，在1和2的NOO反应中存在一种假定的过氧亚硝酸盐（PN）中间体。
