Subphthalocyanine-spiropyran - a versatile system to study photoswitchable fluorescence

荧光是共轭π系统的一种-有时是不需要的-性质，共轭π系统形成了有机电子中使用的所有材料的基础。材料发光的精确控制可用于光学存储器件。这可以通过将光致变色剂引入荧光团附近来实现。本计画利用螺吡喃作为光致变色剂，来改变硼次酞菁（SubPcs）的发光性质。亚酞菁在有机光致发光器件和发光二极管中有着广泛的应用。与螺吡喃的结合为研究光开关对SubPc发光的影响提供了可能。在SubPc，两种不同的连接几何形状的螺吡喃的三个不同的网站是可行的。除了通过近距离的能量转移，螺吡喃可以直接影响SubPcs中的芳香系统。取决于连接位点，螺吡喃充当电子供体或受体，或者从SubPc的pi系统解耦。在一个电环开环为汞环形式后，这些电子影响被逆转。有了这些多功能的构建模块，将有可能设计和研究作为ON/OFF或OFF/ON光开关荧光团的系统。

Fluorescence is a – sometimes unwanted – property of conjugated pi systems that form the basis for all materials that are used in organic electronics. Precise control of a material’s luminescence can be utilized in optical memory devices. This can be achieved by bringing a photochrome into the proximity of the fluorophore. Switching the photochromic moiety can quench the emission of the fluorophore.This project utilizes spiropyran as photochrome to influence the emission properties of boron subphthalocyanines (SubPcs). SubPcs were applied in organic photovoltaics or light emitting diods. The combination with spiropyrans provides the possibility to study the influence of the photoswitch on the SubPc’s emission. At the SubPc, two different linking geometries to three distinct sites of the spiropyran are feasible. Beside energy transfer through close distances, spiropyran can directly influence the aromatic system in SubPcs. Depending on the linking site, spiropyran acts either as electron donor or acceptor, or is decoupled from the pi system of SubPc. After an electrocyclic ring opening to the merocyanine form, these electronic influences are reversed. With these versatile building blocks, it will be possible to design and study systems that act as ON/OFF or OFF/ON photoswitchable fluorophore.