Three isomeric derivatives of 2,2',2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1--benzimidazole) (TPBi) bearing ethyl groups on the -phenyl moieties were synthesized to elucidate the effects of intramolecular interactions on spontaneous orientation polarization (SOP) in thin films. The films of the TPBi derivatives displayed enhanced SOP with a surface potential change of up to 1.8 times that for TPBi, and the -substituted derivative exhibited the largest potential change reported to date (+141.0 mV/nm). Density functional theory calculations and single-crystal structure analysis suggest that the introduction of the ethyl groups switched the stable molecular conformation from to symmetry. Through analysis of the structural anisotropy in the films by spectral ellipsometry and two-dimensional (2D) grazing-incidence wide-angle X-ray scattering, we conclude that the conformational change of the molecules was the major factor underlying the SOP enhancement.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsami.2c03496 | DOI Listing |
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!