Adamantyl side groups boosting the efficiency and thermal stability of organic solid-state fluorescent dyes

Ethyl-adamantyl side groups substituted onto para-bis(2-thienyl)phenylene, a solid-state fluorescent dye, were found to induce pi-pi interactions between the conjugated para-bis(2-thienyl)phenylene cores. At the same time, stacking between the central unit and the adamantyl-containing side group was observed. As a result, due to steric hindrance augmentation of the solid-state, luminescence was observed. Moreover, substitution of standard alkyl side chains with ethyl-adamantyl groups resulted in raising the melting point temperature from 55 degrees C to similar to 250 degrees C. Aside from possible further-functionalization of the para-bis(2-thienyl)phenylene conjugated unit, aforesaid approach can be applied in a wide range of molecules and polymers, when luminescent properties and thermal stability can be tune through the side-chain engineering of organic materials. (C) 2016 Elsevier B.V. All rights reserved.