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N-Doped-carbon-coated 2–4 nm SnO2 nanoparticles were synthesized via a facile metal–organic framework (MOF) coating process followed by a calcination of the SnO2@MOF composite. The as-prepared SnO2 nanoparticles are well dispersed and coated with a uniform nitrogenous carbon structure, which can effectively prevent volume expansion during discharge and charge processes. Benefiting from the advantages of a synergistic effect of SnO2 nanoparticles and carbon structure, these materials exhibit excellent electrochemical performance. For the optimized material SOC-3, a reversible specific capacity of 1032 mA h g−1 was maintained at 100 mA g−1 after 150 cycles with a coulombic efficiency of 99%. When the current was increased to 500 mA g−1, a capacity of 600 mA h g−1 was still attained.

Two novel cocrystals were successfully constructed by 1(2H)-Phthalazinone (PHT) and Tetrafluoroterephthalic acid (TETA) based on O-H⋯O, N-H⋯O, C-H⋯O, C-H⋯F, N-H⋯N and C-H⋯N hydrogen bonding networks, and were well depicted by single crystal diffraction analysis. As predicted by electrostatic potential analysis, the stoichiometry of PHT to TETA is 2:1 and stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The single crystal X-ray diffraction characterized that the two cocrystals were all made up by 2PHT-TETA motif in different ways. AIM analysis and Hirshfeld surfaces indicated the adjacent 2PHT-TETA units assemble through C-H⋯O, C-H⋯F and C-H⋯N hydrogen bonds, producing a 2D plane structure in cocrystal I. Meanwhile, the C-H⋯F, N-H⋯N and C-H⋯O hydrogen bonds between 2PHT-TETA units were the stabilizing factors in cocrystal II. Topological parameters such as ∇2ρ and H revealed the strength of hydrogen bonds were moderate in nature except O31⋯H32-O34 (1.704A, -60.336kJmol-1) in compound I. The hydrogen bonding interactions, cocrystal stability and electron donor-acceptor interactions were investigated using natural bonding orbital analysis. It showed that electron transfer of n(O) σ*(O-H) and n(O) σ*(N-H) between PHT and TETA influence the packing characteristics significantly. Structural changes accompanying cocrystal process have been rationalized through the IR spectrum along with the quantum chemical calculations. The frequency downshifts of CO, N-H and O-H stretching after cocrystallization have been attributed to hydrogen bonding interactions.

A steady self-assembled protonated salt, constructed by Tetrafluoroterephthalic acid (Tera) and 5, 6-dimethyl benzimidazole (DBZ), was designed and prepared in methanol/water solution. The structure and properties were characterized by experimental tests and analyzed by theoretical calculations on molecular level. Excellent symmetry of Tera, proton transfer bridged by water molecule, intermolecular hydrogen bonding play important roles in the self-assemble process. Proton migration analysis confirms the keying action of H2O molecules on co-crystallization. AIM analyses indicate hydrogen bonds are dominant to stabilize crystal packing. In addition, vibrational analysis and luminescent property of the protonated salt were also explored in details.

We demonstrate herein the use of a one-dimensional metal-organic material as a new type of electrode material for lithium-ion batteries (LIBs) in place of the classic porous three-dimensional materials, which are subject to the size of the channel for lithium-ion diffusion and blocking of the windows of the framework by organic solvents during the charging and discharging processes. Introducing a one-dimensional coordination compound can keep organic active substances insoluble in the electrolyte during the charging and discharging processes, providing a facile and general new system for further studies. The results show that both the aromatic ligand and the metal center can participate in lithium storage simultaneously, illustrating a new energy storage mechanism that has been well-characterized by X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and cyclic voltammetry. In addition, the fact that the one-dimensional chains are linked by weak hydrogen bonds rather than strong π-π stacking interactions or covalent bonds is beneficial for the release of capacity entirely without the negative effect of burying the active sites.

MIL-101(Cr)/graphene oxides composites has been successfully synthesized via a facile route using a solvothermal treatment and fully characterized using powder X-ray diffraction (PXRD), scanning electron microscope (SEM), thermal gravimetric analysis (TGA) and infrared spectroscopy (IR). The specific capacity of MIL-101(Cr)/GO are almost twice larger than that of MIL-101(Cr) at the first discharge process and the multiple relationship maintained over 40 cycles, indicating that the electrochemical performance of MIL-101(Cr) as anode material has been improved through doping by GO.

Nanostructured NiP2@C was synthesized by a facile approach via calcination of a Ni-based metal–organic-framework (Ni-MOF-74) with adsorptive red phosphorus, and was tested as an anode material for lithium ion batteries. NiP2 nanoparticles are successfully embedded in situ in porous carbon matrix, constructing crosslinked channels for lithium ion diffusion. The in situ introduction of porous carbon round NiP2 nanoparticles greatly enhances the electronic conductivity. Benefiting from the advantages of porous carbon, the nanostructured NiP2@C electrode material showed excellent electrochemical performance with high reversibility, high rate capability, and long-term cycling stability.

A co-crystal of 1H-benzotriazole (HB) and tetrafluoroterephthalic acid (TETA) has been successfully prepared based on N-H⋯O, O-H⋯N, and C-H⋯F hydrogen bonding interactions and characterized using single crystal X-ray diffraction. Density functional theory (DFT) calculations and vibrational spectroscopy were performed to predict the molecular structure and electronic, chemical, and vibrational properties associated with these hydrogen bonds. Quantitative electrostatic potential analysis (ESP) explained the active hydrogen bonding sites in HB and TETA, and predicted the hydrogen bonding modes in their co-crystal structure. Quantum theory of atoms in molecules (QTAIM) and reduced density gradient (RDG) analyses suggested that the hydrogen bonds present in the HB-TETA co-crystal were moderate in nature expect O-H⋯N (1.735 A, −62.377 kJ mol−1). Meanwhile, the dnorm-mapped Hirshfeld surface of TETA can be used to understand the characteristics of the close contacts; the features were reflected in 2D fingerprint plots. Natural bond orbital (NBO) analysis of the second order perturbation theory indicated that the LP(N19)→σ∗(O5-H7) (26.76 kcal mol−1), LP(O9)→σ∗(N21-H22) (6.69 kcal mol−1), and LP(F1)→σ∗(C24-H25) (6.05 kcal mol−1) interactions were responsible for the weak interactions in the co-crystal. The structural vibrations accompanying these hydrogen bond interactions were characterized by studying the computational HB-TETA model and experimental FT-IR/FT-Raman spectra. The downward shifts observed for the C O, N-H, and O-H stretching modes after co-crystallization were attributed to the hydrogen bonds.

The corrosion inhibiting performance and mechanism of two dithioamide derivatives, N,N′-di-ethyl-dithiodipropinoamide (ED) and N,N′-di-ethyoxylpropyl-dithiodipropinoamide (EPD), for mild steel in 1.0 M HCl solution were investigated by experiments, DFT calculation and MD simulations. EPD and ED are both mixed-type inhibitors with excellent inhibition efficiency (95.2% and of 92.6%, respectively) by weight loss experiments; SEM images also demonstrate the formation of compact inhibiting monolayer. On molecular level, both molecules can be tightly parallel absorbed on Fe (110) surface through S–Fe and O–Fe coordination bounds by the overlapping of heteroatom p orbitals and Fe 3d orbitals, with binding energies of 369.56 kJ/mol and 608.55 kJ/mol. Strong multi-intermolecular H-binding network drives ED and EPD molecules orderly self-assemble on iron surface and form protective monolayer. EPD network keeps intact up to 1.0 MPa, guarantees its potential applications in deep-sea environment.

The formation of host-guest inclusion complexes by Pillar [5]arene (P [5]) and cationic nitrogen heterocyclic molecules were studied by DFT calculations at B3LYP-D3/6-311 + G** level, together with their equilibrium geometries, binding energies and electronic structures. MESP, NCI-RDG and AIM topography analysis were performed to explore underlying interactions. Geometric structures of inclusion complexes were changed compared with the individual molecules; MESP analysis revealed the driving force for the binding process; QTAIM and NCI-RDG methods were utilized to reveal the underlying non-covalent interactions. The inclusion complexes in 1:1 ratio were stabilized through weak C–H⋯O hydrogen bonds, C–H···π, π+···π and van der Waals interactions. The calculated electrophilic charge transfer indicated that charge flowed from P [5] to guests. Gibbs free energy accompanying the recognition process certified that formation of complexes were spontaneous and thermodynamically favorable.