摘要/Abstract

通过Bu^tPCl₂与两倍量原位形成的邻位胺基取代苯基锂的反应合成了二胺基-膦配体H₂（^MesN₂P^Bu-t）和H₂（^dcpN₂P^Bu-t）.利用H₂（^MesN₂P^Bu-t）和H₂（^dcpN₂P^Bu-t）与[Fe（N（SiMe₃）₂）₂]₂的胺消除反应合成得到二胺基-膦配位的高自旋亚铁配合物[（κ³-N，N，P-^MesN₂P^Bu-t）Fe（OEt₂）]（1）和[（κ³-N，N，P-^dcpN₂P^Bu-t）Fe（OEt₂）]（2）.配合物1与重氮化合物（p-tolyl）₂CN₂和PhC（N₂）CO₂Et反应分别生成重氮配位的铁配合物[（κ³-N，N，P-^MesN₂P^Bu-t）Fe（η²-N，N-（p-tolyl）₂CN₂）]（3）和[（κ³-N，N，P-^MesN₂P^Bu-t）Fe（κ²-N，O-PhC（N₂）CO₂Et）]（4）.配合物2可以催化重氮化合物（p-tolyl）₂CN₂转化为酮连氮化合物（p-tolyl）₂-C=NN=C（tolyl-p）₂.配合物2与重氮化合物DmpC（N₂）H反应生成二胺基-膦叶立德配位的高自旋亚铁配合物[（κ³-N，N，C-^dcpN₂P^Bu-tC^H，Dmp）Fe]（5）.二胺基-膦配体H₂（^MesN₂P^Bu-t）和H₂（^dcpN₂P^Bu-t）以及配合物1～5通过了各种谱学数据的表征.其中配合物2～5的结构还通过单晶X射线衍射得到确认.理论计算显示配合物3可看作为低自旋型四价铁末端亚胺基配合物.配合物4的电子结构可描述为中间自旋的三价铁中心与重氮自由基阴离子反铁磁性耦合形成基态自旋为S=1的配合物.
关键词: 铁, 重氮化合物, 二胺基-膦配体
Treatment of Bu^tPCl₂ with 2 equiv. of (2,4,6-Me₃C₆H₂)(2-LiC₆H₄)NLi and (2,6-Cl₂C₆H₃)(2-LiC₆H₄)NLi, which were generated in situ by the interaction of (2,4,6-Me₃C₆H₂)(2-BrC₆H₄)NH and (2,6-Cl₂C₆H₃)(2-BrC₆H₄)NH with 2 equiv. of BuⁿLi, followed by quenching with water, afforded new tridentate diamine-phosphine compounds (o-(N-(2,4,6-Me₃C₆H₂)-NH)C₆H₄)₂PBu^t and (o-(N-(2,6-Cl₂C₆H₃)NH)C₆H₄)₂PBu^t (denoted as H₂(^MesN₂P^Bu-t) and H₂(^dcpN₂P^Bu-t)), respectively. H₂(^MesN₂P^Bu-t) and H₂(^dcpN₂P^Bu-t) underwent amine-elimination reaction with[Fe(N(SiMe₃)₂)₂]₂ (0.5 equiv.) to afford iron(Ⅱ) complexes[(κ³-N,N,P-^MesN₂P^Bu-t)Fe(OEt₂)] (1) and[(κ³-N,N,P-^dcpN₂P^Bu-t)Fe(OEt₂)] (2) bearing tridentate diamido-phosphine ligands. Treatment of 1 with organic diazo compounds (p-tolyl)₂CN₂ and PhC(N₂)CO₂Et rendered the formation of diazo coordinated iron complexes[(κ³-N,N,P-^MesN₂P^Bu-t)Fe(η²-N,N-(p-tolyl)₂CN₂)] (3) and[(κ³-N,N,P-^MesN₂P^Bu-t)Fe(κ²-N,O-PhC(N₂)- CO₂Et)] (4), respectively. Complex 2 can catalyze the conversion of (p-tolyl)₂CN₂ to (p-tolyl)₂C=NN=C(tolyl-p)₂. Treatment of 2 with organic diazo compound DmpC(N₂)H rendered the formation of a high-spin iron(Ⅱ) complex featuring the tridentate bisamido-phosphine ylide ligand[(κ³-N,N,C-^dcpN₂P^Bu-tC^H,Dmp)Fe] (5). These complexes have been characterized by elemental analysis, ¹H NMR, solution magnetic susceptibility measurements, zero-field ⁵⁷Fe Mössbauer spectroscopy and single-crystal X-ray diffraction studies. The spectroscopic data in combination with theoretical study suggest that complex 3 can be viewed as a low-spin iron(IV) imido complex featuring an dianionic ligand[η²-N,N-(p-tolyl)₂CN₂]^2-, whereas 4 has an intermediate-spin iron(Ⅲ) center that is antiferromagnetically coupled to a diazoalkane radical anion[κ²-N,O-PhC(N₂)-CO₂Et)]^•1-.
Key words: iron, diazo compounds, diamido-phosphine ligand


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