Molecular arrangement in diphenylanthracene derivative films deposited under vacuum on in-plane oriented polythiophene films

Abstract

Molecular arrangements of 9,10-diphenylanthracene (DPA) and its derivatives inside films deposited under vacuum were investigated. Two DPA derivatives with alkyl chains, 9,10-Bis(4-methylphenyl)anthracene (diMe-DPA) and 9,10-Bis(4-octylphenyl)anthracene (diOct-DPA), were synthesized and structural analyses of their single crystals were performed. It was clarified that anthracene frames of diMe-DPA and diOct-DPA were arranged uniaxially inside the single crystals by introducing alkyl groups to the DPA. Thin films of these molecules were formed by evaporating them under vacuum on glass substrates and polythiophene (PT) films, in which PT chains were uniaxially aligned parallel to the substrates. The angle between anthracene frames of diMe-DPA and the substrate plane of the PT/glass was smaller than that on the glass substrates. In-plane molecular arrangements were also evaluated, and it was clarified that short axes of the anthracene frames inside diMe-DPA and diOct-DPA were nearly parallel to the PT molecular chain direction.