Carbene-carbanion equilibrium for tris(2-pyridylthio)methanido Fe(II) complexes
Carbene-carbanion equilibrium for tris(2-pyridylthio)methanido Fe(II) complexes
复制标题
DOI：
10.1039/c0dt00615g
复制
发表时间：
2010-01-01
影响因子：
4
通讯作者：
Kinoshita, Isamu
中科院分区：
文献类型：
--
作者：
Kuwamura, Naoto;Kato, Ryo;Kinoshita, Isamu
FeCl(2) 与三(2-吡啶硫基) 甲烷 (tptmH) 反应生成碳负离子络合物 [Fe(tptm)(CH(3)CN)(2)](FeCl(4)){(C(2)H(5))(3)NH}。当使用 FeI(2) 代替 FeCl(2) 时，分离出卡宾配合物 [FeI(pyt)(bptmd)]（pyt = 2-吡啶硫醇，bptmd = 双（2-吡啶硫基）亚甲基）。在氯仿中观察到 [Fe(tptm)(CH(3)CN)(2)](FeCl(4)){(C(2)H(5))(3)NH} 和 [FeI(pyt)(bptmd)] 的卡宾形式 [FeX(pyt)(bptmd)](n+)（n = 1，X = CH(3)CN，n = 0，X = I），而通过核磁共振测量在乙腈中观察到卡宾-碳负离子平衡。使用抗磁性盐 [Fe(tptm)(CH(3)CN)(2)]PF(6) 通过变温 (1)H NMR 测量来评估热力学参数 [Fe(tptm)(CH(3)CN)(2)](+) 可逆箭头 [Fe(pyt)(bptmd)(CH(3)CN)](+) + CH(3)CN (Delta H = 23 kJ mol(-1), Delta S = 55 J mol(-1) K(-1))。
A reaction of FeCl(2) with tris(2-pyridylthio) methane (tptmH) produced the carbanion complex [Fe(tptm)(CH(3)CN)(2)](FeCl(4)){(C(2)H(5))(3)NH}. When FeI(2) was used instead of FeCl(2), the carbene complex [FeI(pyt)(bptmd)] (pyt = 2-pyridinethiolate, bptmd = bis(2-pyridylthio)methylidene) was isolated. The carbene forms [FeX(pyt)(bptmd)](n+) (n = 1 for X = CH(3)CN, n = 0 for X = I) were observed for [Fe(tptm)(CH(3)CN)(2)](FeCl(4)){(C(2)H(5))(3)NH} and [FeI(pyt)(bptmd)] in chloroform, whereas the carbene-carbanion equilibrium was observed in acetonitrile by NMR measurements. The thermodynamic parameters were evaluated by variable temperature (1)H NMR measurements using the diamagnetic salt [Fe(tptm)(CH(3)CN)(2)]PF(6) for [Fe(tptm)(CH(3)CN)(2)](+) reversible arrow [Fe(pyt)(bptmd)(CH(3)CN)](+) + CH(3)CN (Delta H = 23 kJ mol(-1), Delta S = 55 J mol(-1) K(-1)).