Exploring Guest-Dependent Photoconductivity in a Donor-Containing Metal-Organic Framework

Abstract

In this computational study, intercalation of tetracyano acceptor guest molecules in In-2(OH2)TBAPy (TBAPy = 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene) is proposed as a strategy to induce photoconductivity in a previously insulating metal-organic framework (MOF). Analysis of the resulting MOF systems shows that photoconductivity is imparted by the completion of through-space charge transport pathways composed of newly inserted tetracyano acceptor molecules and pyrene donor moieties of the MOF linker. Substitution of Al3+ for In3+Y and perylene for pyrene is subsequently suggested to further optimize the charge transfer between donors and acceptors, leading to a significant enhancement in the optoelectronic behavior. These results show that adaptation of known donor-acceptor chemistry from other materials (e.g., molecular cocrystals) can be a simple, yet effective strategy to design new electroactive MOFs. Furthermore, our findings demonstrate that rational modifications of MOFs based on their chemical tunability can lead to additional control over electroactivity in these materials.