Gorman Jeffrey, Pandya Raj, Allardice Jesse R, Price Michael B, Schmidt Timothy W, Friend Richard H, Rao Akshay, Davis Nathaniel J L K
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K.
School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.
J Phys Chem C Nanomater Interfaces. 2019 Feb 14;123(6):3433-3440. doi: 10.1021/acs.jpcc.8b12061. Epub 2019 Jan 24.
The creation of artificial light-harvesting complexes involves the ordered arrangement of chromophores in space. To guarantee efficient energy-transfer processes, organic dyes must be brought into close proximity, often leading to aggregation and the formation of excimer states. In recent years, the attachment of ligand-based chromophores to nanoparticles has also generated interest in relation to improved solar harvesting and spin-dependent electronic interactions such as singlet fission and upconversion. We explore the covalent attachment of two novel perylene-diimide (PDI) carboxylic acid ligands to silicon dioxide nanoparticles. This allows us to study electronic interactions between the ligands when attached to nanoparticles because these cannot couple to the wide band gap silicon dioxide. One of the synthesized PDI ligands has sterically hindering phenols in the bay position and undergoes minimal optical changes upon attachment, but the other forms an excimer state with a red-shifted and long-lived florescence. As such, molecular structure changes offer a method to tune weak and strong interactions between ligand layers on nanocrystal surfaces.
人工光捕获复合物的创建涉及发色团在空间中的有序排列。为了确保高效的能量转移过程，有机染料必须紧密靠近，这常常导致聚集以及准分子态的形成。近年来，基于配体的发色团与纳米颗粒的连接在改善太阳能捕获以及诸如单线态裂变和上转换等自旋相关电子相互作用方面也引起了人们的兴趣。我们探索了两种新型苝二酰亚胺（PDI）羧酸配体与二氧化硅纳米颗粒的共价连接。这使我们能够研究连接到纳米颗粒上的配体之间的电子相互作用，因为这些配体无法与宽带隙二氧化硅耦合。合成的一种PDI配体在湾区位置具有空间位阻酚，连接后光学变化极小，但另一种形成了具有红移且长寿命荧光的准分子态。因此，分子结构变化提供了一种调节纳米晶体表面配体层之间弱相互作用和强相互作用的方法。
