Diverse ?-? stacking motifs modulate electrical conductivity in tetrathiafulvalene-based metal-organic frameworks.

ABSTRACT: We report three electrically conductive metal-organic frameworks (MOFs) based on a tetrathiafulvalene linker and La³⁺. Depending on the solvent ratios and temperatures used in their solvothermal synthesis, these MOFs crystallize with different topologies containing distinct ?-? stacking sequences of the ligand. Notably, their transport properties correlate rationally with the stacking motifs: longer S···S contact distances between adjacent ligands coincide with lower electrical conductivities and higher activation energies. Diffuse reflectance spectroscopic measurements reveal ligand-based intervalence charge transfer bands in each phase, implicating charge delocalization among mixed-valent tetrathiafulvalene units as the dominant mode of transport. Overall, these frameworks demonstrate how tuning the intermolecular interactions in MOFs serves as a route towards controlling their physical properties.

SUBMITTER: Xie LS 

PROVIDER: S-EPMC6855199 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature