AUTHOR=Gordillo Monica A. , Benavides Paola A. , Spalding Kaybriana , Saha Sourav 

TITLE=A New Electrically Conducting Metal–Organic Framework Featuring U-Shaped cis-Dipyridyl Tetrathiafulvalene Ligands

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.726544

DOI=10.3389/fchem.2021.726544

ISSN=2296-2646

ABSTRACT=<p>A new electrically conducting 3D metal-organic framework (MOF) with a unique architecture was synthesized using 1,2,4,5-tetrakis-(4-carboxyphenyl)benzene (TCPB) a redox-active <italic>cis</italic>-dipyridyl-tetrathiafulvalene (<italic>Z</italic>-DPTTF) ligand. While TCPB formed Zn<sub>2</sub>(COO)<sub>4</sub> secondary building units (SBUs), instead of connecting the Zn<sub>2</sub>-paddlewheel SBUs located in different planes and forming a traditional pillared paddlewheel MOF, the U-shaped <italic>Z</italic>-DPTTF ligands bridged the neighboring SBUs formed by the same TCPB ligand like a sine-curve along the b axis that created a new <italic>sine</italic>-MOF architecture. The pristine <italic>sine</italic>-MOF displayed an intrinsic electrical conductivity of 1 × 10<sup>−8</sup> S/m, which surged to 5 × 10<sup>−7</sup> S/m after I<sub>2</sub> doping due to partial oxidation of electron rich <italic>Z</italic>-DPTTF ligands that raised the charge-carrier concentration inside the framework. However, the conductivities of the pristine and I<sub>2</sub>-treated <italic>sine</italic>-MOFs were modest possibly because of large spatial distances between the ligands that prevented π-donor/acceptor charge-transfer interactions needed for effective through-space charge movement in 3D MOFs that lack through coordination-bond charge transport pathways.</p>