Extended 7,7,8,8-tetracyano-p-quinodimethane-based acceptors: How molecular shape and packing impact electron accepting behavior

Structural analysis of π-extended 7,7,8,8-tetracyano-p-quinodimethane (TCNQ)-based molecules reveal molecular and packing features which may help better understand the weak electron accepting features for these molecules compared with TCNQ, in solution (cyclic voltammetry measurements), while showing varying trends in thin solid films (photoinduced electron transfer measurements). On the basis of the current findings, we propose that unsymmetrical compounds in this series hold promise as good candidates for use in solar cell applications as their molecular features allow for better solid-state packing, a property likely conducive for better charge transport. Electron acceptor/donor pairs of compatible molecular shapes rather than the usually sought planar shapes may offer a route worth pursuing.