A 3D Cu‐Naphthalene‐Phosphonate Metal–Organic Framework with Ultra‐High Electrical Conductivity [article]

Craig A. Peeples, Delf Kober, Franz‐Josef Schmitt, Patrik Tholen, Konrad Siemensmeyer, Quinn Halldorson, Bünyemin Çoşut, Aleksander Gurlo, Ahmet Ozgur Yazaydin, Gabriel Hanna, Gündoğ Yücesan, Technische Universität Berlin
2020
A conductive phosphonate metal–organic framework (MOF), [{Cu(H2O)}(2,6‐NDPA)0.5] (NDPA = naphthalenediphosphonic acid), which contains a 2D inorganic building unit (IBU) comprised of a continuous edge‐sharing sheet of copper phosphonate polyhedra is reported. The 2D IBUs are connected to each other via polyaromatic 2,6‐NDPA's, forming a 3D pillared‐layered MOF structure. This MOF, known as TUB40, has a narrow band gap of 1.42 eV, a record high average electrical conductance of 2 × 102 S m−1 at
more » ... oom temperature based on single‐crystal conductivity measurements, and an electrical conductance of 142 S m−1 based on a pellet measurement. Density functional theory (DFT) calculations reveal that the conductivity is due to an excitation from the highest occupied molecular orbital on the naphthalene‐building unit to the lowest unoccupied molecular orbital on the copper atoms. Temperature‐dependent magnetization measurements show that the copper atoms are antiferromagnetically coupled at very low temperatures, which is also confirmed by the DFT calculations. Due to its high conductance and thermal/chemical stability, TUB40 may prove useful as an electrode material in supercapacitors.
doi:10.14279/depositonce-11093 fatcat:vump6hdimbd5tmbpkz357idy3u