Square planar vs tetrahedral geometry in four coordinate iron(II) complexes
Square planar vs tetrahedral geometry in four coordinate iron(II) complexes
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DOI：
10.1021/ic048202
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发表时间：
2005-05-02
影响因子：
4.6
通讯作者：
Chirik, PJ
中科院分区：
文献类型：
--
作者：
Hawrelak, EJ;Bernskoetter, WH;Chirik, PJ
本文系统地研究了一个四配位铁（Ⅱ）d（6）配合物的几何构型，其通式为L_2FeX_2。Fe-2（MeS）（4）（Mes = 2，4，6-Me_3C_6H_2）与单齿膦和亚磷酸酯配体反应得到正方形平面的反式-P_2Fe（MeS）（2）衍生物。的几何形状的识别已完成的组合的解决方案和固态磁力，并在两种情况下（P = PMe 3，PEt 2 Ph），X射线衍射。相比之下，在与螯合膦配体络合时观察到四面体和正方形平面配位。结晶学和磁化率数据的组合（depe）Fe（MeS）2（depe = 1，2-bis（diethylphosphino）ethane）建立了四面体分子几何结构，而SQUID磁强计和穆斯堡尔谱对（dppe）Fe（Mes）2（dppe = 1，2-bis（diphenylphosphino）ethane）样品的分析表明其为平面分子。当溶解在氯化溶剂中时，后一种化合物促进氯原子夺取，形成四面体（dppe）Fe（Mes）Cl和（dppe）FeCl 2。配体取代反应已被研究的两种结构类型，并迅速在NMR时间尺度在环境温度下。
The geometric preferences of a family of four coordinate, iron(II) d(6) complexes of the general form L2FeX2 have been systematically evaluated. Treatment of Fe-2(MeS)(4) (Mes = 2,4,6-Me3C6H2) with monodentate phosphine and phosphite ligands furnished square planar trans-P2Fe(MeS)(2) derivatives. Identification of the geometry has been accomplished by a combination of solution and solid-state magnetometry and, in two cases (P = PMe3, PEt2Ph), X-ray diffraction. In contrast, both tetrahedral and square planar coordination has been observed upon complexation of chelating phosphine ligands. A combination of crystallographic and magnetic susceptibility data for (depe)Fe(MeS)2 (depe = 1, 2-bis(diethylphosphino)ethane) established a tetrahedral molecular geometry whereas SQUID magnetometry and Mossbauer spectroscopy on samples of (dppe)Fe(Mes)2 (dppe = 1,2-bis(diphenylphosphino)ethane) indicated a planar molecule. When dissolved in chlorinated solvents, the latter compound promotes chlorine atom abstraction, forming tetrahedral (dppe)Fe(Mes)CI and (dppe)FeCl2. Ligand substitution reactions have been studied for both structural types and are rapid on the NMR time scale at ambient temperature.