Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure.
Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure.
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二元离子卟啉纳米片：晶体结构调节的电子和光捕获特性。
DOI：
10.1039/c2nr11826b
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发表时间：
2012
期刊：
影响因子：
6.7
通讯作者：
J. Shelnutt
中科院分区：
文献类型：
--
作者：
Yongming Tian;C. Beavers;T. Busani;Kathleen E. Martin;J. L. Jacobsen;B. Mercado;B. Swartzentruber;F. van Swol;C. Medforth;J. Shelnutt
由阴离子和阳离子卟啉自组装的晶体固体提供了一类新的多功能光电微米和纳米材料。答1：四（4-磺酸基苯基）卟啉锌（II）（ZnTPPS）和四（N-甲基-4-吡啶鎓基）卟啉锡（IV）（SnTNMePyP）的组合得到具有高纵横比和不同厚度的卟啉纳米片。纳米片的室温制备提供了合作二元离子（CBI）固体的第一个X射线晶体结构。晶胞含有一个半分子的水-ZnTPPS（4-）（电子供体）和三个半分子的二羟基-SnTNMePyP（4+）（电子受体）。在没有任何非卟啉离子的情况下达到固体中的电荷平衡，如先前通过非晶体学手段对其他CBI纳米材料所确定的。晶体结构揭示了一个复杂的分子排列与滑移π-π堆积只发生在孤立的二聚体的一个对称独特的锌卟啉。与晶体结构一致，未观察到指示激子离域和扩展的π-π堆叠的UV-可见J聚集带。XRD测量表明，Zn/Sn纳米片的结构不同于先前报道的Zn/Sn四叶草状CBI固体。与表现出J聚集带并且是光电导的Zn/Sn三叶草相比，纳米片不是光电导的。即便如此，纳米片在人工光合作用系统中充当捕光结构，能够将水还原为氢，但效率不如Zn/Sn三叶草。
Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1 : 1 combination of zinc(II) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(IV) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room temperature preparation of the nanosheets has provided the first X-ray crystal structure of a cooperative binary ionic (CBI) solid. The unit cell contains one and one-half molecules of aquo-ZnTPPS(4-) (an electron donor) and three half molecules of dihydroxy-SnTNMePyP(4+) (an electron acceptor). Charge balance in the solid is reached without any non-porphyrinic ions, as previously determined for other CBI nanomaterials by non-crystallographic means. The crystal structure reveals a complicated molecular arrangement with slipped π-π stacking only occurring in isolated dimers of one of the symmetrically unique zinc porphyrins. Consistent with the crystal structure, UV-visible J-aggregate bands indicative of exciton delocalization and extended π-π stacking are not observed. XRD measurements show that the structure of the Zn/Sn nanosheets is distinct from that of Zn/Sn four-leaf clover-like CBI solids reported previously. In contrast with the Zn/Sn clovers that do exhibit J-aggregate bands and are photoconductive, the nanosheets are not photoconductive. Even so, the nanosheets act as light-harvesting structures in an artificial photosynthesis system capable of reducing water to hydrogen but not as efficiently as the Zn/Sn clovers.