A facile protection–deprotection route for obtaining indigo pigments as thin films and their applications in organic bulk heterojunctions†
Eric Daniel Głowacki,Gundula Voss,Kadir Demirak,Marek Havlicek,Nevsal Sünger,Aysu Ceren Okur,Uwe Monkowius,Jacek Gąsiorowski,Lucia Leonat,Niyazi Serdar Sariciftci
Abstract
Indigo and its derivatives are industrially-important dyes known for centuries. The low solubility of these compounds limits their applications and hinders potential synthetic chemistry using indigo as a building-block. Herein we report attachment of the tert-butoxy carbonyl (tBOC) thermolabile protecting group to indigos, allowing their processing into neat thin films as well as mixed films with a semiconducting polymer. Photoinduced charge transfer is observed to and from these pigments and the polymer.