Premium
Columnar Benzoperylene‐Hexa‐ and Tetracarboxylic Imides and Esters: Synthesis, Mesophase Stabilisation and Observation of Charge‐Transfer Interactions between Electron‐Donating Esters and Electron‐Accepting Imides
Author(s) -
Kelber Julien,
Achard MarieFrance,
Garreaude Bonneval Bénédicte,
Bock Harald
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201100939
Subject(s) - mesophase , perylene , acceptor , chemistry , hexa , electron acceptor , columnar phase , alkyl , crystallography , electron donor , phase (matter) , polymer chemistry , photochemistry , organic chemistry , molecule , catalysis , physics , condensed matter physics
Benzo[ ghi ]perylene 1,2,4,5,10,11‐hexacarboxylic trialkylimide and dialkylimido‐dialkyl ester derivatives, displaying a thermodynamically stable hexagonal columnar liquid‐crystalline phase at room temperature, have been obtained by the use of previously unexplored chiral racemic α‐branched alkylimide functions. One of the trialkylimides described here is the first room temperature columnar solely oligo‐alkylimide‐substituted arene, and thus constitutes a prototype case of self‐assembling organic acceptor materials. As the related hexacarboxylic hexaesters are found to exhibit only a weak tendency to form columnar mesophases, benzo[ ghi ]perylene 1,2,5,10‐tetracarboxylic tetraalkyl esters have been synthesized by regioselective oxidative Diels–Alder addition of maleic anhydride to 3,10‐dicyanoperylene, and a room temperature hexagonal columnar mesophase was obtained with branched alkyl chains. The acceptor‐type electronic properties of the tri‐ and diimides have been found to be considerably more pronounced than those of the hexa‐ and tetracarboxylic esters, and to approach those of the prototype acceptor material C 60 . The formation of bathochromically absorbing donor–acceptor complexes was observed with a di‐ or triimide as acceptor and a tetraester as donor, but not with a hexaester as donor. Exploiting the non‐negligible differences in reduction and oxidation potentials between all four types of materials, the minimum HOMO energy difference necessary for charge‐transfer‐complex formation has been determined to lie between 0.29 and 0.35 eV.