Martirosyan Garik G, Azizyan Arsen S, Kurtikyan Tigran S, Ford Peter C
Armenian Research Institute of Applied Chemistry (ARIAC), 375005, Yerevan, Armenia.
Inorg Chem. 2006 May 15;45(10):4079-87. doi: 10.1021/ic051824q.
The heterogeneous reaction between NO gas and sublimed layers of manganese(II) porphyrinato complexes Mn(Por) (Por = TPP (tetraphenylporphyrinato dianion), TMP (tetramesitylporphyrinato dianion), or TPP(d20) (perdeuterated tetraphenylporphyrinato dianion)) has been monitored by IR and optical spectroscopy over the temperature range of 77 K to room temperature. These manganese porphyrins promote NO disproportionation to NO2 species and N2O, and the reaction proceeds via several distinct stages. At 90 K, the principal species observed spectrally are the nitric oxide dimer, cis-ONNO, two manganese nitrosyls, the simple NO adduct Mn(Por)(NO), and another intermediate (1) that is apparently critical to the disproportionation mechanism. This key intermediate is formed prior to N2O evolution, and proposals regarding its likely structure are offered. When the system is warmed to 130 K, the disproportionation products, N2O and the O-coordinated nitrito complex Mn(Por)(NO)(ONO) (2), are formed. IR spectral changes show that, upon further warming to 200 K, 2 isomerizes into the N-bonded nitro linkage isomer Mn(Por)(NO)(NO2) (3). After it is warmed to room temperature, the latter species loses NO and converts to the known 5-coordinate nitrito complex Mn(Por)(ONO) (4).
通过红外光谱和光学光谱在77 K至室温的温度范围内监测了一氧化氮气体与锰（II）卟啉配合物Mn（Por）（Por = TPP（四苯基卟啉二价阴离子）、TMP（四（对甲苯基）卟啉二价阴离子）或TPP（d20）（全氘代四苯基卟啉二价阴离子））升华层之间的多相反应。这些锰卟啉促进NO歧化成NO2物种和N2O，并且反应通过几个不同阶段进行。在90 K时，光谱观察到的主要物种是一氧化氮二聚体、顺式-ONNO、两种锰亚硝酰基、简单的NO加合物Mn（Por）（NO）以及另一种对歧化机理显然至关重要的中间体（1）。这个关键中间体在N2O逸出之前形成，并提出了关于其可能结构的建议。当系统升温至130 K时，形成了歧化产物N2O和O配位的亚硝酸根配合物Mn（Por）（NO）（ONO）（2）。红外光谱变化表明，进一步升温至200 K时，2异构化为N键合的硝基连接异构体Mn（Por）（NO）（NO2）（3）。升温至室温后，后一种物质失去NO并转化为已知的五配位亚硝酸根配合物Mn（Por）（ONO）（4）。
