Conformational Landscapes of Metal(II) Porphyrinato, Chlorinato, and Morpholinochlorinato Complexes
Conformational Landscapes of Metal(II) Porphyrinato, Chlorinato, and Morpholinochlorinato Complexes
复制标题
金属（II）卟啉、氯化和吗啉氯化配合物的构象景观
DOI：
10.1021/acs.inorgchem.7b00799
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发表时间：
2017
影响因子：
4.6
通讯作者：
Brückner, Christian
中科院分区：
文献类型：
--
作者：
Sharma, Meenakshi;Ticho, Alexander L.;Samankumara, Lalith;Zeller, Matthias;Brückner, Christian
[中四芳基卟啉]金属配合物的大环构象是金属依赖的。此外，已知氢卟啉和它们的一些类似物比母体卟啉具有更强的构象柔性，但这在多大程度上反映在它们的金属依赖构象上的研究要少得多。中-四芳基morpholinochlorins本质上是非平面的氯类似物，其中五元吡啶部分被六元morphololine部分所取代。制备了介芳基2,3-二甲氧基氯和介芳基morpholinochlorins的金属配合物（M = Ni2+, Cu2+, Zn2+, Pd2+, Ag2+）。用x射线晶体结构衍射法确定了它们的构象，并与它们的自由碱基以及相应的金属卟啉的构象进行了比较。面外位移图分别可视化和量化了吡咯片段逐步转化为二甲氧基吡咯啉片段和二氧基啉片段时的构象变化。一般的非平面大环构象与中心金属有关，较小的离子表现出更多的非平面构象，而金属氯通常表现出比相应的金属氯大得多的构象范围，而金属氯又比相应的卟啉更非平面。这证明了与氯大环甚至卟啉大环相比，茂叶绿氯大环具有更大的构象灵活性。非平面性的程度影响金属配合物的电子结构，这也可以从它们的紫外-可见光谱的比较中看出。因此，我们进一步定义了控制吡咯修饰卟啉的构象和电子效应。
The macrocycle conformation of [meso-tetraarylporphyrinato]metal complexes is metal-dependent. Furthermore, hydroporphyrins and some of their analogues are known to be more conformationally flexible than the parent porphyrins, but the extent to which this is reflected in their metal-dependent conformations was much less studied.meso-Tetraarylmorpholinochlorins are intrinsically nonplanar chlorin analogues in which the five-membered pyrroline moiety was replaced by a six-membered morpholine moiety. The metal complexes (M = Ni2+, Cu2+, Zn2+, Pd2+, Ag2+) ofmeso-aryl-2,3-dimethoxychlorins andmeso-arylmorpholinochlorins were prepared. Their conformations were determined using X-ray crystal structure diffractometry and compared against those of their free bases, as well as against the conformations of the corresponding metalloporphyrins. Out-of-plane displacement plots visualized and quantified the conformational changes upon stepwise conversion of a pyrrole moiety to a dimethoxypyrroline moiety and to a dialkoxymorpholine moiety, respectively. The generally nonplanar macrocycle conformations were found to be central-metal-dependent, with the smaller ions showing more nonplanar conformations and with the metallomorpholinochlorins generally showing a much larger conformational range than the corresponding metallochlorins, which, in turn, were more nonplanar than the corresponding porphyrins. This attests to the larger conformational flexibility of the morpholinochlorin macrocycle compared to that of a chlorin or even a porphyrin macrocycle. The degree of nonplanarity affects the electronic structure of the metal complexes, as can also be seen in a comparison of their UV–vis spectra. We thus further define the conformational and electronic effects governing pyrrole-modified porphyrins.