Vanin Anatoly F, Sanina Natalia A, Serezhenkov Vladimir A, Burbaev Dosymzhan Sh, Lozinsky Vladimir I, Aldoshin Sergey M
Semenov Institute of Chemical Physics, Russian Academy of Sciences, Russian Federation.
Nitric Oxide. 2007 Feb;16(1):82-93. doi: 10.1016/j.niox.2006.07.005. Epub 2006 Aug 5.
Parameters of the EPR signals of monomeric dinitrosyl-iron complexes with 1H-1,2,4-triazole-3-thiol (DNIC-MT), obtained by treating MT+ferrous iron in DMSO solution with gaseous NO, have been compared with those of the crystalline monomeric DNIC-MT with tetrahedral structure. Dissolved DNIC-MT were characterized by the isotropic EPR signal centered at g=2.03 with half-width of 0.7 mT and quintet hyperfine structure when recorded at ambient temperature or the anisotropic EPR signal with g( perpendicular)=2.045, g( parallel)=2.014 from frozen solution at 77 kappa, Cyrillic. DNIC-MT in crystalline state showed the structure-less symmetrical singlet EPR signal centered at g=2.03 and half-width of 1.7 mT at both room and liquid nitrogen temperature. The Lorentz shape of this signal indicates the strong exchange interaction between these complexes in the DNIC-MT crystal. Being dissolved in DMSO the crystalline sample of DNIC-MT demonstrated the EPR signal typical for DNIC-MT, obtained by treating MT+ferrous iron in DMSO solution with gaseous NO. Low spin (S=1/2) d(9) electron configuration of DNIC-MT with tetrahedral structure (formula (MT-S(.))(2)Fe(-1)(NO(+))(2)) was suggested to be responsible for the signal of DNIC-MT in crystalline state. Dissolving of the crystals of DNIC-MT may result in the change of their spatial and electronic structure, namely, tetrahedral structure of the complexes characterized by low spin d(9) electronic configuration transforms into a plane-square structure with d(7) electronic configuration and low spin S=1/2 state (formula (MT- S(-))(2)Fe(+)(NO(+))(2)). The latter was suggested to be characteristic of other DNICs with various thiol-containing ligands in the solutions. The proposed mechanism of these DNICs formation from ferrous iron, thiol and NO shows that the process could be accompanied by the ionization of NO molecules to NO(+) and NO(-) ions in the complexes. Detailed analysis of the shape of the EPR signals of these complexes provided additional information about the exchange interaction typical for DNIC-MT in crystals.
通过在二甲基亚砜（DMSO）溶液中用气态一氧化氮（NO）处理1H-1,2,4-三唑-3-硫醇（MT）与亚铁得到的单体二亚硝基铁配合物（DNIC-MT）的电子顺磁共振（EPR）信号参数，已与具有四面体结构的结晶单体DNIC-MT的参数进行了比较。溶解的DNIC-MT的特征在于，在室温下记录时，各向同性EPR信号以g = 2.03为中心，半高宽为0.7 mT，具有五重态超精细结构；或者在77 K（西里尔文）的冷冻溶液中，具有g（垂直）= 2.045、g（平行）= 2.014的各向异性EPR信号。结晶态的DNIC-MT在室温和液氮温度下均显示出以g = 2.03为中心、半高宽为1.7 mT的无结构对称单重态EPR信号。该信号的洛伦兹形状表明DNIC-MT晶体中这些配合物之间存在强交换相互作用。将DNIC-MT的结晶样品溶解在DMSO中后，显示出通过在DMSO溶液中用气态NO处理MT +亚铁得到的DNIC-MT的典型EPR信号。具有四面体结构（分子式(MT-S(·))(2)Fe(-1)(NO(+))(2)）的DNIC-MT的低自旋（S = 1/2）d(9)电子构型被认为是结晶态DNIC-MT信号的原因。DNIC-MT晶体的溶解可能导致其空间和电子结构发生变化，即具有低自旋d(9)电子构型的配合物的四面体结构转变为具有d(7)电子构型和低自旋S = 1/2状态（分子式(MT - S(-))(2)Fe(+)(NO(+))(2)）的平面正方形结构。后者被认为是溶液中具有各种含硫醇配体的其他DNIC的特征。从亚铁、硫醇和NO形成这些DNIC的 proposed 机制表明，该过程可能伴随着配合物中NO分子电离为NO(+)和NO(-)离子。对这些配合物的EPR信号形状的详细分析提供了有关DNIC-MT晶体中典型交换相互作用的额外信息。 （注：原文中“proposed”未翻译完整，推测可能是“提出的”之类意思，这里保留英文供你参考完整意思）
