Bart Suzanne C, Lobkovsky Emil, Bill Eckhard, Chirik Paul J
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
J Am Chem Soc. 2006 Apr 26;128(16):5302-3. doi: 10.1021/ja057165y.
Treatment of the iron bis(dinitrogen) complex, (iPrPDI)Fe(N2)2 (iPrPDI = (2,6-iPr2C6H3N=CMe)2C5H3N), with a series of aryl azides resulted in loss of 3 equiv of N2 and formation of the corresponding four-coordinate iron imide compounds, (iPrPDI)Fe(NAr). These complexes, two of which (Ar = 2,6-iPr2-C6H3 and 2,4,6-Me3-C6H2) have been characterized by X-ray diffraction, are significantly distorted from planarity. The metrical parameters in combination with Mössbauer spectroscopic and SQUID magnetic data suggest an intermediate spin iron(III) center antiferromagnetically coupled to a ligand-centered radical. Nitrene group transfer has been accomplished by addition of 1 atm of CO, yielding aryl isocyanates, ArNCO, and (iPrPDI)Fe(CO)2. Hydrogenation of the more sterically hindered members of the series furnished free aniline and the previously reported iron dihydrogen complex. Catalytic aryl azide hydrogenation has also been achieved, and the observed relative rates are consistent with N-H bond formation as the rate-determining step in aniline formation.
用一系列芳基叠氮化物处理双（二氮）铁配合物（iPrPDI）Fe（N₂）₂（iPrPDI =（2,6-iPr₂C₆H₃N = CMe）₂C₅H₃N），导致3当量的N₂损失并形成相应的四配位铁酰亚胺化合物（iPrPDI）Fe（NAr）。这些配合物中的两种（Ar = 2,6-iPr₂-C₆H₃和2,4,6-Me₃-C₆H₂）已通过X射线衍射表征，明显偏离平面性。测量参数与穆斯堡尔光谱和超导量子干涉仪磁数据相结合表明，一个中间自旋铁（III）中心与一个以配体为中心的自由基反铁磁耦合。通过加入1个大气压的CO实现了氮烯基团转移，生成芳基异氰酸酯ArNCO和（iPrPDI）Fe（CO）₂。该系列中空间位阻较大的成员的氢化反应生成了游离苯胺和先前报道的二氢铁配合物。还实现了催化芳基叠氮化物氢化反应，观察到的相对速率与N-H键形成作为苯胺形成中的速率决定步骤一致。
