We report herein the first example of interpenetration isomerism in covalent organic frameworks (COFs). As a well-known three-dimensional (3D) COF, COF-300 was synthesized and characterized by the Yaghi group in 2009 as a 5-fold interpenetrated diamond structure ( dia-c5 topology). We found that adding an aging process prior to the reported synthetic procedure afforded the formation of an interpenetration isomer, dia-c7 COF-300. The 7-fold interpenetrated diamond structure of this new isomer was identified by powder X-ray diffraction and rotation electron diffraction analyses. Furthermore, we proposed a universal formula to accurately determine the number of interpenetration degrees of dia-based COFs from only the unit cell parameters and the length of the organic linker. This work not only provides a novel example to the category of interpenetration isomerism but also provides new insights for the further development of 3D COFs.

An anisotropic high-spin qubit with long coherence time could scale the quantum system up. It has been proposed that Grover's algorithm can be implemented in such systems. Dimetallic aza[80]fullerenes M@CN (M = Y or Gd) possess an unpaired electron located between two metal ions, offering an opportunity to manipulate spin(s) protected in the cage for quantum information processing. Herein, we report the crystallographic determination of Gd@CN for the first time. This molecular magnet with a collective high-spin ground state (S = 15/2) generated by strong magnetic coupling (J = 350 ± 20 cm) has been unambiguously validated by magnetic susceptibility experiments. Gd@CN has quantum coherence and diverse Rabi cycles, allowing arbitrary superposition state manipulation between each adjacent level. The phase memory time reaches 5 μs at 5 K by dynamic decoupling. This molecule fulfills the requirements of Grover's searching algorithm proposed by Leuenberger and Loss.

sunlight for sustainable energy conversion and storage. [1] For renewable and efficient hydrogen production, electrochemical water splitting employing renewable electrical energy is a promising route due to its inherent advantages, including readily available reactant, stable output, and feasibility of large-scale production. [2] However, the large overpotential (η) of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) greatly limited their practical applications. Moreover, due to the thermodynamic limitation, the HER reaction usually prefers to be conducted under strong acidic solution while the OER is conducted under basic solution. [3] Extra energy needs to be supplied in order to maintain the pH differences between those two reactions. It is thus imperative to develop highly active electrocatalysts that can utilize under a wide pH range. At present, the state-ofthe-art electrocatalysts for HER are precious metal Pt-based materials and for OER are costly Ir-or Ru-based oxides. [4] But the high cost, scarcity and unsatisfactory durability of above mentioned catalysts further limit the practical utilization of the water splitting technology. [5] Water splitting requires development of cost-effective multifunctional materials that can catalyze both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) efficiently. Currently, the OER relies on the noble-metal catalysts; since with other catalysts, its operation environment is greatly limited in alkaline conditions. Herein, an advanced water oxidation catalyst based on metallic Co 9 S 8 decorated with single-atomic Mo (0.99 wt%) is synthesized (Mo-Co 9 S 8 @C). It exhibits pronounced water oxidization activity in acid, alkali, and neutral media by showing positive onset potentials of 200, 90, and 290 mV, respectively, which manifests the best Co 9 S 8 -based singleatom Mo catalyst till now. Moreover, it also demonstrates excellent HER performance over a wide pH range. Consequently, the catalyst even outperforms noble metal Pt/IrO 2 -based catalysts for overall water splitting (only requiring 1.68 V in acid, and 1.56 V in alkaline). Impressively, it works under a current density of 10 mA cm −2 with no obvious decay during a 24 h (0.5 m H 2 SO 4 ) and 72 h (1.0 m KOH) durability experiment. Density functional theory (DFT) simulations reveal that the synergistic effects of atomically dispersed Mo with Co-containing substrates can efficiently alter the binding energies of adsorbed intermediate species and decrease the overpotentials of the water splitting.