STEREOCHEMISTRY OF COORDINATION GROUP IN AN IRON(3) DERIVATIVE OF TETRAPHENYLPORPHINE
STEREOCHEMISTRY OF COORDINATION GROUP IN AN IRON(3) DERIVATIVE OF TETRAPHENYLPORPHINE
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DOI：
10.1021/ja00985a004
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发表时间：
1967-01-01
影响因子：
15
通讯作者：
GLICK, MD
中科院分区：
文献类型：
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作者：
HOARD, JL;COHEN, GH;GLICK, MD
对Fleischer等人报道的四方晶体的X-射线数据进行了重新分析，考虑到(1)所研究的材料实际上是四苯基卟啉(ClFeTPP)的氯铁(III)衍生物(ClFeTPP)，以及(2)晶体中分子的取向无序，在任何一种化学公式上，这对解释实验数据都是重要的。在重结晶之前对原始制剂的化学分析支持，但没有确定ClFeTPP的组成。每个公式的结构模型都为极性配位基团沿c方向的平行和反平行取向分配了相等的概率；这些模型的独立改进产生了一对统计平均的分子，它们具有客观上不可区分的几何结构。ClFeTPP公式对实验数据和推导结果的每一个方面都提供了合理的解释，而H2OFeOHTPP公式需要几个相当不确定的详细解释。ClFeTPP分子中的四方锥体配位基团Fe-N=2.049±0.009 A，Fe-Cl=2.192±0.012 A，与氯化高铁血红素相似。铁原子与氮原子的离面位移为0.383±0.005 A。
The X-ray data reported by Fleischer, et al.,* for tetragonal crystals assumed to be the aquohydroxyiron-(III) derivative of tetraphenylporphine (H2OFeOHTPP) are reanalyzed to take account of (1) the probability thatthe material studied was in fact the chloroiron (III) derivative of tetraphenylporphine (ClFeTPP) and (2) orientational disorder of the molecules in the crystal that, on either chemical formulation, is of major importance in interpreting the experimental data. Chemical analysis of the original preparation prior to recrystallization supports, but does not establish, the ClFeTPP composition. The structural modelfor each formulation assigns equal probabilities for parallel and antiparallel orientation of the polar coordination group along c; independent refinement of these models yields a pair of statistically averaged molecules that have objectively indistinguishable geometries. The ClFeTPP formulation provides a rational accounting for every aspect of the experimental data and the derived results, whereas the H2OFeOHTPPformulation requires several detailed interpretations that are rather uncon-vincing. The square-pyramidal coordination group in the ClFeTPP molecule, with Fe-N= 2.049±0.009 A and Fe-Cl= 2.192±0.012 A, closelyresembles that in chlorohemin. The iron atom is displaced out-of-plane from the nitrogen atoms by 0.383±0.005 A.