Siamese-Twin Porphyrin Goes Platinum: Group 10 Monometallic, Homobimetallic, and Heterobimetallic Complexes
Siamese-Twin Porphyrin Goes Platinum: Group 10 Monometallic, Homobimetallic, and Heterobimetallic Complexes
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DOI：
10.1021/acs.inorgchem.0c00714
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发表时间：
2020-05-18
影响因子：
4.6
通讯作者：
Meyer, Franc
中科院分区：
文献类型：
--
作者：
Dorazio, Sarina J.;Vogel, Anastasia;Meyer, Franc
制备了一系列Pt-II基单金属（H2 PtL）、同双金属（Pt 2L）和杂金属（NiPtL和PdPtL）的10族扩展孪晶卟啉（H4 L）配合物。结构表征的Pt-II系列（Pt 2L，NiPtL，和PdPtL）显示其相似的一般结构，与离子大小的轻微差异。金属离子插入过程的改进也允许有效地制备已知的Pd 2L络合物，并且还对新的杂环化合物NiPdL络合物进行了结构表征。紫外-可见光谱，NMR光谱，磁圆二色性（MCD），和（光谱）电化学被用来表征的配合物;电子性质主要遵循既定的线的双卟啉金属配合物，除了Pt-II-为基础的系统表现出更复杂的紫外-可见光谱特征。MCD光谱伴随着密度泛函理论（DFT）/含时DFT计算（TDDFT）合理化的孪生卟啉的光学特性的起源。可以看到非平面的非芳香族大环π系统的存在，其共轭途径局限于分子的每一半。在可见光区的几个跃迁中，预测了显着的吡唑（pi）->吡咯（pi*）电荷转移特性。这项研究增加了我们的基本理解的形成，结构和电子结构的ESTA类扩展的金属卟啉含有nonpyrrolic部分的配合物。
A series of Pt-II-based monometallic (H2PtL), homobimetallic (Pt2L), and heterobimetallic (NiPtL and PdPtL) group 10 complexes of the previously established expanded twin porphyrin (H4L) were prepared. Structural characterization of the bimetallic Pt-II series (Pt2L, NiPtL, and PdPtL) revealed their similar general structures, with slight differences correlated to the ion size. An improvement of the metal-ion insertion process also allowed efficient preparation of the known Pd2L complex, and the novel heterobimetallic NiPdL complex was also structurally characterized. UV-vis spectroscopy, NMR spectroscopy, magnetic circular dichroism (MCD), and (spectro)electrochemistry were used to characterize the complexes; the electronic properties followed largely established lines for metal complexes of the twin porphyrin, except that the Pt-II-based systems exhibited more complex UV-vis spectral signatures. MCD spectra accompanied by density functional theory (DFT)/time-dependent DFT computations (TDDFT) rationalize the origins of the optical features of the twin porphyrin. The presence of the nonplanar, nonaromatic macrocyclic pi system with conjugation pathways confined to each half of the molecule could be visualized. Significant pyrazole(pi) -> pyrrole(pi*) charge-transfer character was predicted for several transitions in the visible region. This study adds to our fundamental understanding of the formation, structure, and electronic structure of bimetallic complexes of this class of expanded metalloporphyrins containing nonpyrrolic moieties.