Metal-organic frameworks (MOFs) possess great structural diversity because of the flexible design of linker groups and metal nodes. The structure-property correlation has been extensively investigated in areas like chiral catalysis, gas storage and absorption, water purification, energy storage, etc. However, the use of MOFs in lithium storage is hampered by stability issues, and how its porosity helps with battery performance is not well understood. Herein, through anion and thermodynamic control, we design a series of naphthalenediimide-based MOFs 1-4 that can be used for cathode materials in lithium-ion batteries (LIBs). Complexation of the N,N'-di(4-pyridyl)-1,4,5,8-naphthalenediimide (DPNDI) ligand and CdX (X = NO or ClO) produces complexes MOFs 1 and 2 with a one-dimensional (1D) nonporous network and a porous, noninterpenetrated two-dimensional (2D) square-grid structure, respectively. With the DPNDI ligand and Co(NCS), a porous 1D MOF 3 as a kinetic product is obtained, while a nonporous, noninterpenetrated 2D square-grid structure MOF 4 as a thermodynamic product is formed. The performance of LIBs is largely affected by the stability and porosity of these MOFs. For instance, the initial charge-discharge curves of MOFs 1 and 2 show a specific capacity of ∼47 mA h g with a capacity retention ratio of >70% during 50 cycles at 100 mA g, which is much better than that of MOFs 3 and 4. The better performances are assigned to the higher stability of Cd(II) MOFs compared to that of Co(II) MOFs during the electrochemical process, according to X-ray diffraction analysis. In addition, despite having the same Cd(II) node in the framework, MOF 2 exhibits a lithium-ion diffusion coefficient (D) larger than that of MOF 1 because of its higher porosity. X-ray photoelectron spectroscopy and Fourier transform infrared analysis indicate that metal nodes in these MOFs remain intact and only the DPNDI ligand undergoes the revisible redox reaction during the lithiation-delithiation process.

We report the development of a heterogeneous catalyst system on continuous flow chemistry. A palladium (Pd) coated tubular reactor was placed in line with copper (Cu) tubing using a continuous flow platform, and a Sonogashira C-C coupling reaction was used to evaluate the performance. The reactions were favorably carried out in the Cu reactor, catalyzed by the traces of leached Pd from the Pd reactor. The leached Pd and Cu were trapped with a metal scavaging resin at the back-end of the continuous flow system, affording a genuine approach toward green chemistry.

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A networked spin cage comprising infinite CoL cages arrays (where Co = Co(NCS) and L = 1,3,5-tri-(4-pyridyl)-verdazal radical) is synthesized and found to exhibit tunable magnetic and electrochemical properties via inclusion of guests. SQUID investigation reveals the coexistence of ferromagnetic and anti-ferromagnetic interactions between the Co(II) ion center and radical ligands. Inclusion of electron-deficient guests (e.g., tetracyanoethylene) dramatically enhances spin concentration and increases anti-ferromagnetic interactions due to the formation of charge-transfer complex between the host and the guest. In addition, introduction of electron-rich guests (e.g., tetrathiafulvalene) into the networked spin cages doubles the capacity for binding the lithium ions.