Jump to main content
Jump to site search


Band gap engineering of donor–acceptor co-crystals by complementary two-point hydrogen bonding

Author affiliations

Abstract

We report a detailed investigation of a series of new charge-transfer (CT) complexes assembled via a two-point complementary hydrogen bonding (H-bonding) of diindolopyrrole (DIP) electron donors with o-quinone and diazafluorenone acceptors. Unidirectional polarization through the DD⋯AA type H-bonding leads to a dramatic perturbation of electronic levels of the donor and the acceptor. π-Stacking of the H-bonded pairs results in strong charge-transfer (HOMO–LUMO) interactions in their ground state, manifested in low energy optical absorption. Density functional theory (DFT) calculations predict a H-bonding induced rise of the HOMOD (by up to 0.5 eV) and lowering of the LUMOA (by up to 0.7 eV). As a result, the complexes of relatively weak electron donors and acceptor ability exhibit remarkably low optical energy gaps (down to <0.8 eV), that can be tuned by varying the ionization potential and electron affinity of the individual components. Single crystal X-ray analysis for 6 complexes displayed H-bond lengths between 1.9 and 2.3 Å and short π-stacking distances (≥3.2 Å), in line with strong donor–acceptor interactions. Thin-film transistors of such a H-bonded complex, fabricated by vacuum co-sublimation of PhDIP and pyrenetetraone, showed ambipolar charge transport with unusual ‘double dip’ characteristics.

Graphical abstract: Band gap engineering of donor–acceptor co-crystals by complementary two-point hydrogen bonding

Back to tab navigation

Supplementary files

Article information


Submitted
20 Jul 2020
Accepted
09 Oct 2020
First published
14 Oct 2020

Mater. Chem. Front., 2020, Advance Article
Article type
Research Article

Band gap engineering of donor–acceptor co-crystals by complementary two-point hydrogen bonding

N. Yee, A. Dadvand and D. F. Perepichka, Mater. Chem. Front., 2020, Advance Article , DOI: 10.1039/D0QM00500B

Social activity

Search articles by author

Spotlight

Advertisements