Prodigiosin analogue designed for metal coordination: stable zinc and copper pyrrolyldipyrrins.
Prodigiosin analogue designed for metal coordination: stable zinc and copper pyrrolyldipyrrins.
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DOI：
10.1021/ic5008439
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发表时间：
2014-07-21
影响因子：
4.6
通讯作者：
Tomat, Elisa
中科院分区：
文献类型：
--
作者：
Chang, Tsuhen M.;Sinharay, Sanhita;Astashkin, Andrei V.;Tomat, Elisa
吡咯基二吡咯基序存在于几种天然存在的灵菌红素色素中。然而，灵菌红素与过渡金属的相互作用和金属结合的吡咯基二吡咯的性质的潜在作用，一直难以评估，因为数量非常有限的充分表征的稳定络合物。在这里，我们表明，一个内消旋芳基取代基和乙基酯基团的顺序组装过程中的三个杂环的引入提供了一个吡咯基二吡咯增强的协调能力相比，天然灵菌红素。紫外-可见吸收研究表明，该配体迅速结合Zn（II）离子与2：1配体-金属化学计量和Cu（II）离子与1：1化学计量。值得注意的是，不需要添加碱来形成所得的稳定络合物。晶体结构表明，而四面体锌中心从事每个配体上的两个氮供体，pseudosquare平面铜配合物的功能协调的所有三个吡咯氮原子，并采用酯基作为中性配体。通过电子顺磁共振光谱法研究了氧化还原活性过渡金属在完全共轭的吡咯基二吡咯骨架内配位的第一个例子，表明晶体结构中发现的1：1的金属与配体比例也在溶液中保持。吡咯基二吡咯基序，其特征在于细菌来源的灵菌红素天然产物，被工程化以提供用于过渡金属配位的稳定的三吡咯骨架。锌和铜离子的迅速结合在室温下不存在添加的碱的情况下发生。通过X射线衍射和EPR/ENDOR技术的完整结构和光谱表征记录了迄今为止在该配体框架中的Cu（II）离子的难以捉摸的配位。
The pyrrolyldipyrrin motif is found in several naturally occurring prodigiosin pigments. The potential roles of the interactions of prodigiosins with transition metals and the properties of metal-bound pyrrolyldipyrrins, however, have been difficult to assess because of the very limited number of well-characterized stable complexes. Here, we show that the introduction of a meso-aryl substituent and an ethyl ester group during the sequential assembly of the three heterocycles affords a pyrrolyldipyrrin of enhanced coordinating abilities when compared to that of natural prodigiosins. UV–visible absorption studies indicate that this ligand promptly binds Zn(II) ions with 2:1 ligand-to-metal stoichiometry and Cu(II) ions with 1:1 stoichiometry. Notably, no addition of base is required for the formation of the resulting stable complexes. The crystal structures reveal that whereas the tetrahedral zinc center engages two nitrogen donors on each ligand, the pseudosquare planar copper complex features coordination of all three pyrrolic nitrogen atoms and employs the ester group as a neutral ligand. This first example of coordination of a redox-active transition metal within a fully conjugated pyrrolyldipyrrin framework was investigated spectroscopically by electron paramagnetic resonance to show that the 1:1 metal-to-ligand ratio found in the crystal structure is also maintained in solution. The pyrrolyldipyrrin motif, which characterizes the prodigiosin natural products of bacterial origin, is engineered to afford a stable tripyrrolic scaffold for coordination of transition metals. Prompt binding of zinc and copper ions occurs in the absence of added bases at room temperature. Full structural and spectroscopic characterization by X-ray diffraction and EPR/ENDOR techniques documents the hitherto elusive coordination of the Cu(II) ion in this ligand framework.
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影响因子：
1.5
作者：
Broering, Martin;Koehler, Silke;Pietzonka, Clemens
通讯作者：
Pietzonka, Clemens
DOI：
10.1002/cmr.b.20064
发表时间：
2006-08-01
影响因子：
0.9
作者：
Astashkin, A. V.;Enemark, J. H.;Raitsimring, A.
通讯作者：
Raitsimring, A.
影响因子：
21.8
作者：
Davis, Jeffery T.;Gale, Philip A.;Quesada, Roberto
通讯作者：
Quesada, Roberto
影响因子：
3.6
作者：
Garcia-Valverde, Maria;Alfonso, Ignacio;Quesada, Roberto
通讯作者：
Quesada, Roberto
影响因子：
56.9
作者：
Hennessy, Elisabeth T.;Betley, Theodore A.
通讯作者：
Betley, Theodore A.