Here, a porous cobalt–organic framework with pillared layer structures, namely [Co3OBA3PTD(H2O)2⋅ 2 DMA⋅H2O]n (1, H2OBA=4,4′‐oxybis(benzoic acid); PTD=6‐(pyridin‐4‐yl)‐1,3,5‐triazine‐2,4‐diamine), was fabricated by using cobalt trinuclear nodes, low‐cost carboxylic linker, and accessible nitrogen heterocyclic ligands. This compound exhibited a highly efficient solvatochromism towards CH2Cl2 within one minute and can be used 200 times at least. The corresponding dropper detector was assembled as a practical sensor. Meanwhile, the porous Co3O4 was obtained by a simple but effective annealing treatment. Electrochemical measurements confirm that this Co3O4 material derived from compound 1 shows high and stable lithium storage capabilities (1081.75 mA h g−1 at 200 mA g−1 after 115 cycles) and excellent rate properties.

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Recently, MOF-derived (metal-organic framework) 2D materials, due to the special structure of the MOF inherited, have become a potential candidate for application in energy storage and conversion. In this work, a new 2D layered CoÀ MOF was synthesized as the precursor for fabricating Napoleon-like Co 3 O 4 (NLÀ Co 3 O 4). The monolayer thickness of NLÀ Co 3 O 4 is approximately 70 nm. The unique structure of layered porous of NLÀ Co 3 O 4 derived from CoÀ MOF plays an important role in improving electrochemical and electro-catalysis properties. As lithium ion battery anode material, NLÀ Co 3 O 4 shows out-bound cycling performance and rate capacity, which has an unprecedented high reversible capacity of 1120.5 mA h g À 1 at 200 mA g À 1 after 300 cycles and high rate capacities of 579.4 mA h g À 1 under the current density of 6.4 A g À 1. NLÀ Co 3 O 4 still exhibits capacity of 679 and 576 mA h g À 1 after 200 cycles at high current densities of 1 and 4 A g À 1 , respectively. Moreover, NLÀ Co 3 O 4 has efficient oxygen evolution reduction (OER) catalytic performance (overpotential, ca. 420 mV), comparable with commercial RuO 2. During the process of continuous catalysis of OER, NLÀ Co 3 O 4 shows good durability for about 15 h.

Five new nuclear coordination complexes based on a 2-hydroxymethylpyridine (Hhmp) ligand, [Cu4­(hmp)4­(CHOO)2­(H2­O)2]­(ClO4)2·2H2O (1), [Cu8­(hmp)8­(CHOO)4­(CH3­CN)2­(H2­O)4]­(ClO4)4·2CH3­CN (2), {[Cu2­(hmp)2­(CHOO)­(H2O)]­ClO4·H2­O}n (3), [Co9­(hmp)6­(CHOO)6­(CO3)2­(H2­O)6]­(ClO4)2·11H2O (4), and [Co9­(hmp)6­(CHOO)7­(CO3)2­(H2­O)5]­ClO4·CH3­CN·12H2O (5), have been synthesized through evaporation at room temperature. As expected, by changing the ratio of the mixed solvent complexes, 1–3 successfully grow from a [Cu4O4] monocubane (1) to octanuclear double-cubane (2), which then further extends into polycubane (3, one-dimensional chain) via bridging ligands of formate. By changing the metal source, complexes 4 and 5 with a similar {Co9} cluster are successfully obtained. One water molecule coordinated with CoII in one [Co4O4] core of complex 4 has been replaced by a formate anion in complex 5, resulting in the {Co9} cluster with +2 and +1 charges, respectively. The change of charges on the clusters results in different cluster alignments, changing the intermolecular interactions in 4 and 5. Magnetic measurements show that antiferromagnetism interaction changes into weak ferromagnetic interaction in complexes 1–3, while the antiferromagnetic behavior turns to glass spin in complexes 4 and 5.

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