Guest-promoted modulation of the electronic states in metal−organic frameworks (MOFs) has brought about a new field of interdisciplinary research, including host−guest chemistry and solid-state physics. Although there are dozens of studies on guestpromoted enhancement of the electrical conductivity properties, including stoichiometry, conductive carriers and structure−property relationships have been scarcely studied in detail. Herein, we studied the effects of continuous and controlled bromine vapor doping on structural, optical, thermoelectric, and semiconducting properties of Cu[Cu(pdt) 2 ] (pdt = 2,3-pyrazinedithiolate) as a function of bromine stoichiometry. We demonstrated that the same material could act as both p-and n-type semiconductors by tuning the stoichiometry of Br doped in Br x @Cu[Cu(pdt) 2 ], and a change in the charge-carrier type from holes in pristine MOF to electrons upon bromine vapor doping was observed. Bromine molecules acted as an oxidant, causing the selective oxidation of [Cu II (pdt) 2 ] in the host framework. In addition, a redox hopping pathway between the partially oxidized Cu II /Cu III center contributed to the enhancement of the electrical conductivity of the MOF.

We report the synthesis, characterization, and electronic properties of the quinoid-based three-dimensional metal–organic framework [Fe2(dhbq)3]. The MOF was synthesized without using cations as a template, unlike other reported X2dhbq3-based coordination polymers, and the crystal structure was determined by using single-crystal X-ray diffraction. The crystal structure was entirely different from the other reported [Fe2(X2dhbq3)]2–; three independent 3D polymers were interpenetrated to give the overall structure. The absence of cations led to a microporous structure, investigated by N2 adsorption isotherms. Temperature dependence of electrical conductivity data revealed that it exhibited a relatively high electrical conductivity of 1.2 × 10–2 S cm–1 (E a = 212 meV) due to extended d-π conjugation in a three-dimensional network. Thermoelectromotive force measurement revealed that it is an n-type semiconductor with electrons as the majority of charge carriers. Structural characterization and spectroscopic analyses, including SXRD, Mössbauer, UV–vis–NIR, IR, and XANES measurements, evidenced the occurrence of no mixed valency based on the metal and the ligand. [Fe2(dhbq)3] upon incorporating as a cathode material for lithium-ion batteries engendered an initial discharge capacity of 322 mAh/g.

We propose a novel method based on the inverse problem approach to optimize the shape of a magnet generates high uniformity of magnetic fields in a magnetometer with diamond nitrogen-vacancy (NV) centers. Our original method can determine the combination of magnetic moments required to design a unique magnet shape. We obtained a unique shape of the small magnet (optimized model, 15 × 15 × 25 mm3 and 25 × 25 × 15 mm3) for integrated magnetometry system and improved the magnetic uniformity from 83.6% to 99.0% in the diamond NV centers area ( X = −1–1 mm, Y = −1–1 mm, Z = 5–6 mm). The results indicate a highly sensitive magnetometer with a diamond NV center for future biomedical applications.