Understanding Cross-Conjugation for Organic Electronics

Abstract

pi-Conjugated organic molecules have been the focus of interest since they have been probed as potential semiconducting materials,[1] suitable for replacing the widely used silicon technologies. Their structural, optical and conductive properties are now under study to improve their application in organic electronics and to make possible their ad hoc synthesis. In this sense, the knowledge of the pi-electron delocalization is crucial to stablish the relation between the properties and the function, enabling the development of a synthesis guide based on the specific application. The most acknowledged conjugated organic materials are those which present extended, linearlyconjugated pi-systems. [1,2] However, this is not the only way of pi-electron delocalization: homoconjugation, cross-conjugation, curved-conjugation, etc. constitute different electronic designs to achieve new organic materials. There is a relative high abundance in the organic world of cross-conjugated but limited comprehension. [1,2,3] Thus, the understanding of how cross-conjugation works in -electronic systems is of importance. Following this idea, in this project we show 4 different structures which present two perpendicular pi-conjugated paths and how the cross-conjugated property is revealed. On the one hand, two molecules based on thieno[3,4-c]pyrrole-4,6-dione quaterthiophenes[2,3] allow us toaccomplish the subject from the aromatic/quinoidal outlook, and, on the other hand, two molecules with an anthanthrone core make possible the study from the perspective of the substituent groups. [4]