Di‐ and Tetracyano‐Substituted Pyrene‐Fused Pyrazaacenes: Aggregation in the Solid State

Abstract

Five di‐ and tetracyano‐substituted pyrene‐fused pyrazaacenes were synthesized and studied as potential electron acceptors in the solid state. Single crystals of all compounds were grown and the crystal packing studied by DFT calculations (transfer integrals and reorganization energies) to get insight into possible use for semiconducting charge transport.

Isostructural Charge-Transfer Cocrystals Based on Triptycene End-Capped Quinoxalinophenanthrophenazine

“…For the formation of CT crystals, six small electron-deficient compounds were chosen: (i) 2,4-dinitro toluene ( DNT ), a common target analyte for the sensing of explosives, (ii) phenanthroquinoxaline dicarbonitrile ( PQDC ), which has a slightly larger aromatic system with pronounced π-stacking tendency, and (iii) TCNQ and its fluorinated derivatives F x TCNQ ( x = 1, 2, 4), which are, due to their extremely low LUMO levels, benchmark electron acceptors and are beneficial for increased charge transfer. ,,,,,, The synthesis and crystal structures of QPP-OMe and PQDC , have already been described before. The cocrystals were all grown by vapor diffusion of methanol into solutions of equimolar mixtures of QPP-OMe and the various acceptors in CHCl 3 .…”

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“…In their search for solid-state electron acceptors, the Mastalerz group revisited four previously known di- and tetracyano-substituted pyrene-fused pyrazaacenes and synthesized a new derivative 151.2 . 291 Except 151.1 , single crystals from all known compounds were grown for the first time. 151.1 and 151.2 were prepared by condensing pyrenedione 149.1a with 2,3-diaminomaleonitrile and 4,5-diaminophthalonitrile, respectively, under acidic conditions ( Scheme 151 ).…”

“… Reagents and conditions: (a) 291 2,3-diaminomaleonitrile, EtOH/AcOH (1:1), 80 °C, 11–16 h; (b) 4,5-diaminophthalonitrile, EtOH/AcOH (1:1), 80 °C, 11–16 h. …”

Triptycene End‐Capping as Strategy in Materials Chemistry to Control Crystal Packing and Increase Solubility

“… [31] This rather unusual packing was reproducible several times and under different conditions and therefore seemed to be favored over other modifications. This prompted us to crystallize QPP‐OMe in the presence of small electron deficient molecules (2,4‐dinitrobenzene ( DNB ), phenanthroquinoxaline dicarbonitrile ( PQDC ), [33] tetracyanoquinodimethane ( TCNQ ) and its fluorinated derivatives F x TCNQ ; (x = 1, 2, 4) [34] . As expected, the packing of QPP‐OMe remained unchanged, with the acceptor molecules intercalated between the dimers in the former void.…”