Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Chemphyschem. 2011 Feb 25;12(3):580-94. doi: 10.1002/cphc.201000947. Epub 2011 Feb 17.
We discuss artificial photonic antenna systems that are built by incorporating chromophores into one-dimensional nanochannel materials and by organizing the latter in specific ways. Zeolite L (ZL) is an excellent host for the supramolecular organization of different kinds of molecules and complexes. The range of possibilities for filling its one-dimensional channels with suitable guests has been shown to be much larger than one might expect. Geometrical constraints imposed by the host structure lead to supramolecular organization of the guests in the channels. The arrangement of dyes inside the ZL channels is what we call the first stage of organization. It allows light harvesting within the volume of a dye-loaded ZL crystal and also the radiationless transport of energy to either the channel ends or center. One-dimensional FRET transport can be realized in these guest-host materials. The second stage of organization is realized by coupling either an external acceptor or donor stopcock fluorophore at the ends of the ZL channels, which can then trap or inject electronic excitation energy. The third stage of organization is obtained by interfacing the material to an external device via a stopcock intermediate. A possibility to achieve higher levels of organization is by controlled assembly of the host into ordered structures and preparation of monodirectional materials. The usually strong light scattering of ZL can be suppressed by refractive-index matching and avoidance of microphase separation in hybrid polymer/dye-ZL materials. The concepts are illustrated and discussed in detail on a bidirectional dye antenna system. Experimental results of two materials with a donor-to-acceptor ratio of 33:1 and 52:1, respectively, and a three-dye system illustrate the validity and challenges of this approach for synthesizing dye-nanochannel hybrid materials for light harvesting, transport, and trapping.
我们讨论了通过将发色团纳入一维纳米通道材料并以特定方式组织后者来构建的人工光子天线系统。沸石 L（ZL）是超分子组织不同种类分子和配合物的极好宿主。已经表明，用合适的客体填充其一维通道的可能性范围比人们预期的要大得多。主体结构施加的几何约束导致客体在通道中进行超分子组织。我们将染料在 ZL 通道内的排列称为组织的第一阶段。它允许在负载染料的 ZL 晶体的体积内进行光捕获，并实现能量无辐射传输到通道的末端或中心。这种客体-宿主材料可以实现一维 FRET 传输。组织的第二阶段是通过在 ZL 通道的末端耦合外部供体或受体截止荧光团来实现的，然后可以捕获或注入电子激发能量。组织的第三阶段是通过在外部设备与材料之间通过截止阀中间体进行接口来实现的。通过将主体控制组装成有序结构并制备单向材料，可以实现更高水平的组织。通过折射率匹配和避免混合聚合物/染料-ZL 材料中的微相分离，可以抑制 ZL 通常强烈的光散射。在双向染料天线系统上详细说明了并讨论了这些概念。具有供体-受体比分别为 33:1 和 52:1 的两种材料以及三染料系统的实验结果说明了这种方法用于合成用于光收集、传输和捕获的染料-纳米通道混合材料的有效性和挑战。
