Intramolecular hydrogen bonding with the participation of the nitrogen atom of five- and six-membered heterocycles

Hydrogen-Bond-Promoted Planar Conformation, Crystallinity, and Charge Transport in Semiconducting Diazaisoindigo Derivatives

“…Compounds N , N ′-bis­(2-octyldodecyl)-6,6′-di­(1 H -indol-7-yl)-7,7′-diazaisoindigo ( o - AID ) and N , N ′-bis­(2-octyldodecyl)-6,6′-di­(1 H -indol-7-yl)-5,5′-diazaisoindigo ( p - AID ) were designed as the models for this work. In these molecules, we employed a design of H-bond “donor–acceptor-donor” systems, with indole as the flanking H-bond donor units and nitrogen-containing diazaisoindigo units as the H-bond acceptor in the center. , The central moieties in o - AID and p - AID (7,7′-diazaisoindigo and 5,5′-diazaisoindigo, respectively) were selected because of (i) their promising optoelectronic properties and (ii) their ability to form strain-free, favorable six-membered ring H-bonds , with indole. We also designed a non-H-bonded control compound N , N ′-bis­(2-octyldodecyl)-6,6′-di­(1 H -indol-7-yl)-isoindigo ( ID-C ), which had a very similar constitution, compared to o - AID and p - AID, except for its non-nitrogen-containing center unit.…”