Crystal and Molecular Structure of the Silver(II) and Zinc(II) Derivatives of meso- Tetraphenylporphyrin.
Crystal and Molecular Structure of the Silver(II) and Zinc(II) Derivatives of meso- Tetraphenylporphyrin.
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内消旋四苯基卟啉的银（II）和锌（II）衍生物的晶体和分子结构。
DOI：
10.1002/chin.198628090
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
J. Hoard
中科院分区：
文献类型：
--
作者：
W. Scheidt;J. U. Mondal;C. Eigenbrot;A. Adler;L. Radonovich;J. Hoard
测定了四配位四苯基卟啉酸银（II）和锌（II）的晶体结构和分子结构。这两种配合物均在三斜体系中结晶，并与母体大环HjTPP的三斜改性呈同构。这两种配合物的中心对称配位基的键距在统计上是不相等的。化合物的晶体排列特征表明，这种不对称性是由不对称的晶格排列引起的。Ag-N的平均距离为2.092 Á(个别值为2.082（3)和2.101 (3)Á）， Zn-N的平均距离为2.037 Á(个别值为2.045（2)和2.029 (2)A）。AgTPP晶体数据：三斜，a= 10.503 (2) a, b= 12.485 (2) a, c= 6.351 (2) a, a= 97.72 (1)， ß= 100.68 (1), 7= 97.150 (9)， Z= 1，空间群Pi， 5616个观测数据，P = 0.059。ZnTPP晶体数据：三斜，a= 10.382 (1) a, b= 12.421 (2) a, c= 6.443 (1) a, a= 98.30 (1), d= 101.15 (1), y= 96.47 (1)， Z= 1，空间群Pi， 3729个观测数据，J？, = 0.036。由于各种不同的原因，四坐标AgTPP和ZnTPP4的结构测定间隔了好几年。然而，两者有一个共同的重要特征，那就是晶体填塞约束可能会调制卟啉到氮-金属键的距离。在这些d9和d10配合物中，MN键长度的统计显著变化在任何电子基础上都是意想不到的。然而，值得注意的是，这两种同形配合物的晶体学相似性，以及三斜型H2TPP的晶体学相似性5表明，这种偏差的基础在于晶体堆积效应。虽然这一结论主要基于间接证据，但锌（II）和银（II）衍生物的比较支持了这一结论，锌（II）和银（II）衍生物代表了尺寸和络合要求明显不同的金属离子。AgTPP最初是作为具有大中心金属离子的一系列金属卟啉衍生物的一员（在康奈尔大学）进行研究的。这些研究旨在探讨准刚性卟啉大环中可能影响的径向膨胀的极限。d9银离子的络合确实导致了大环的径向膨胀；Ag-N的平均键距为2.092 Á。一个完全不可参与的结构特征是两个晶体学上独特的络合距离：2.082(3)和2.101 (3)Á的巨大差异。考虑到核中其他化学上相等的键距之间的接近一致，这种差异出乎意料地大。事实上，0.019 Á的差值是差值的正式估计标准差的5倍。三斜H2TPP的某些构象特征，虽然完全适用于减轻H2TPP晶体中环内H-H接触，但令人惊讶的是，它们仍然存在于AgTPP的晶体结构中。不相等的Ag-N键距离似乎是结晶agtpp中意想不到的构象特征保留的结果，而构象本身是不对称结晶环境的结果。两个Ag-N键距离中哪一个最适合无约束核（Dih几何）是不确定的。几年后（在巴黎圣母院），在其他研究过程中制备了未溶剂化形式的ZnTPP7晶体
The crystal and molecular structures of four-coordinate silver (II) and zinc (II) tetraphenylporphyrinates have been determined. Both complexes crystallize in the triclinic system and are isomorphous with the triclinic modification of the parent macrocycle HjTPP. Bond distances in the centrosymmetric coordination groups of both complexes are found to be statistically nonequivalent. Features of the crystal packing of the compounds suggest that this inequivalence arises from asymmetric lattice packing. The average Ag-N distance is 2.092 Á (individual values 2.082 (3) and 2.101 (3) Á), and that for Zn-N is 2.037 Á (individual values 2.045 (2) and 2.029 (2) A). Crystal data for AgTPP: triclinic, a= 10.503 (2) A, b= 12.485 (2) A, c= 6.351 (2) A, a= 97.72 (1), ß= 100.68 (1), 7= 97.150 (9), Z= 1, space group Pi, 5616 observed data, P,= 0.059. Crystal data for ZnTPP: triclinic, a= 10.382 (1) A, b= 12.421 (2) A, c= 6.443 (1) A, a= 98.30 (l), d= 101.15 (1), y= 96.47 (1), Z= 1, space group Pi, 3729 observed data, J?,= 0.036.The determinations of structure for four-coordinate AgTPP and ZnTPP4 were performed several years apart for a disparate variety of reasons. However, one important feature common to both is the probable modulation of porphinato nitrogen-metal bond distances by crystal-packing constraints. The statistically sig-nificant variation inthe complexing MN bond lengths in these d9 and d10 complexes is unexpected on any electronic grounds. However, it is to be noted that crystallographic similarities in these two isomorphous complexes, along with that of triclinic H2TPP, 5 suggest that the basis for the deviations lies incrystal-packing effects. This conclusion, although principally based on indirect evidence, is buttressed by the comparison of the zinc (II) and silver (II) derivatives, which represent metal ions of significantly different size and complexing requirements. AgTPP was initially studied (at Cornell) as a member of a series6 of metalloporphyrin derivatives with large central metal ions. These studies were designed to probe the limits of radial expansion that could be effected in the quasi-rigid porphyrin macrocycle. Complexation of the d9 silver ion does indeed lead to substantial radial expansion of the macrocycle; the average Ag-N bond distance was found to be 2.092 Á. A wholly unan-ticipated structural feature is the large disparity in the two crystallographically unique complexing distances: 2.082 (3) and 2.101 (3) Á. This difference is unexpectedly large considering the close agreement between other chemically equivalent bond distances in the core. Indeed, the difference of 0.019 Á is 5 times the formal estimated standard deviation for the difference. Certain conformational features of triclinic H2TPP, while wholly appropriate for relieving intraannular H—H contacts in crystalline H2TPP, surprisingly remain in the crystal structure of AgTPP. It seemed plausible that the unequal Ag-N bond distances were the consequence of this unexpected retention of conformational features in crystallineAgTPP and that the conformation was itself a result of an asymmetric crystalline environment. It was uncertain which of the two Ag-N bond distances represents that most appropriate for an unconstrained core(Dih geometry). Some years later (at Notre Dame), crystals of an unsolvated form of ZnTPP7 were prepared in the course of other investiga-