Hydrogen-bonded organic framework modified separator for simultaneously enhancing the safety and electrochemical performance of Ni-rich lithium-ion battery

Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.

High-throughput mechanistic study of highly selective hydrogen-bonded organic frameworks for electrochemical nitrate reduction to ammonia

Hydrogen-bonded organic frameworks(HOFs),an emerging porous macrocyclic materials linked by hydrogen-bond,hold potential for gas separation and storage,sensors,optical,and electrocatalysts.Here,HOF-based electrocatalysts are rationally developed for nitrates reduction to ammonia,allowing not only to regulate wastewater pollution but also to accomplish carbon-neutral ammonia(NH_(3))synthesis.We preform high-throughput computational screening of thirty-six HOFs with various metals as active sites,denoted as HOF-M1,for nitrate reduction reaction(NO_(3)RR)toward NH_(3).We have implemented a hierarchical four-step screening strategy,and ultimately,HOF-Ti1 was selected based on its exceptional catalytic activity and selectivity in the NO_(3)RR process.Through additional analysis,we discovered that the d band center of the active metal sites serves as an effective parameter for designing and predicting the performance of HOFs in NO_(3)RR.This research not only showcases the immense potential of electrocatalysis in transforming NO_(3)RR into NH_(3)but also provides researchers with a compelling incentive to undertake further experimental investigations.

Theoretical Studies on Intermolecular Hydrogen-bond Interactions between Hexamethylenetetramine and Nitric Acid

The structures of the complexes generated by hexamethylenetetramine and nitric acid have been fully optimized by B3LYP method at the 6-311＋＋G＊＊ and aug-cc-pVTZ levels. The intermolecular hydrogen-bonding interactions have been calculated by the B3LYP/6-311＋＋G＊＊, B3LYP/aug-cc-pVTZ, MP2（full）/6-311＋＋G＊＊ and CCSD（T）/6-311＋＋G＊＊ methods, respectively. The NBO （nature bond orbital）, AIM （atom in molecule）, temperature effect and solvation effect have been analyzed to reveal the origin of the interactions. The results indicate that the stable hydrogen-bonded complexes could be generated by hexamethylenetetramine and nitric acid. The interactions follow the order of （a）（e）（b）（c）（d）（f）（g）. The C–N bonds which are adjacent to the methylene involving the hydrogen bonds tend to break in the chemical reaction. Due to the exothermic process, low temperature is conducive to the formation of the composition, which tallies with the experimental result.

Synthesis of a New Porphyrin-fluorescein Hybrid and its Supramolecular Self-assembly with Amino-porphyrinatomanganese(Ⅲ) by Hydrogen-bonding

A new porphyrin-fluorescein hybrid 2 (Fl-PPTPP) has been synthesized and characterized by UV-Vis, IR, H-NMR, ESI-MS and elemental analysis. The supramolecular 1 self-assembly of Fl-PPTPP with amino-porphyrinatomanganese [Mn (p-APTPP)Cl] by hydrogen-bonding was studied using fluorescence spectroscopic titration and ESI-MS.

Self-assembly constructed by perylene bisimide derivatives bearing complementary hydrogen-bonding moieties

An intermediate compound 2, 4-bis（laurylamino）-6-（1-（2-aminoethyl）-piperazine）-1, 3, 5-triazine was prepared by stepwise nucleophilic substitution on triazine ring by lauryl amine and subsequently 1-（2-aminoethyl）-piperazine. Then imidization of perylene-3, 4, 9, 10-tetracarboxylic acid dianhydride with 2,4-bis（laurylamino）-6-（1-（2-aminoethyl）-piperazine）-1, 3, 5-triazine was carried out to afford a novel perylene derivative bearing two melamine blocks （S2） and 1, 6, 7, 12-tetra（4-tert-butyl phenoxy）-perylene-3, 4, 9, 10-tetracarboxylic acid bisimide （S1. The hydrogen-bonding interactions between S1 and S2 were investigated by IH NMR spectrum, UV/Vis spectrum and fluorescence spectrum. The influences on the morphologies of S1·S2 aggregates were investigated. The results show that well-defined nanofibers with a diameter of about 100 nm can be obtained by self-assembly between S1 and S2 only in CH2Cl2 solution. Based on these results, guidelines for the molecular design and self-assembly of supramolecular polymer materials are presented.

A Novel Hydrogen-bonded Three-dimensional Network Complex Containing Nickel

A novel complex, (H 3O) 2[Ni(2,6-pydc) 2]·2H 2O was synthesized in an aqueous solution and characterized by means of single-crystal X-ray diffraction, elemental analyses and IR spectra. The X-ray structural analysis revealed that the novel compound forms three-dimensional(3D) networks by both π-π stacking and hydrogen-bonding interactions. The crystal data for the complex are a=13.853(3) nm, b=9.6892(19) nm, c=13.732(3) nm, α=90.00°, β=115.52(3)°, γ=90.00°, Z=3, R 1=0.0786, wR 2=0.1522.

An intravenous clarithromycin lipid emulsion with a high drug loading, H-bonding and a hydrogen-bonded ion pair complex exhibiting excellent antibacterial activity

The aim of this study was to develop an intravenous clarithromycin lipid emulsion(CLE)with good stability and excellent antibacterial activity. The CLE was prepared by the thinfilm dispersed homogenization method. The interaction between clarithromycin(CLA) and cholesteryl hemisuccinate(CHEMS) was confirmed by DSC, FT-IR and^1H NMR analysis. The interfacial drug loading, thermal sterilization, freeze–thaw stability, and in vitro and in vivo antibacterial activity were investigated systematically. DSC, FT-IR and^1H NMR spectra showed that CHEMS(CLA: CHEMS, M ratio 1:2) could interact with CLA through H-bonding and a hydrogen-bonded ion pair. The CHEMS was found necessary to maintain the stability of CLE.Ultracentrifugation showed that almost 88% CLA could be loaded into the interfacial layer.The optimized CLE formulation could withstand autoclaving at 121 °C for 10 min and remain stable after three freeze–thaw cycles. The in vitro susceptibility test revealed that the CLA–CHEMS ion-pair and CLE have similar activity to the parent drug against many different bacterial strains. The in vivo antibacterial activity showed that the ED50 of intravenous CLE was markedly lower than that of CLA solution administrated orally. CLE exhibited pronounced antibacterial activity and might be a candidate for a new nanocarrier for CLA with potential advantages over the current commercial formulation.

Hydrogen-Bond Symmetrization of δ-AlOOH

The 6-AIOOH can transport water into the deep mantle along cold subducting slab geotherm. We investigate the hydrogen-bond symmetrization behavior of 6-AIOOH under the relevant pressure-temperature condition of the lower mantle using ab initio molecular dynamics （MD）. The static symmetrization pressure of 30.0 GPa can be reduced to 17.0 GPa at 30014 by finite-temperature （T） statistics, closer to the experimental observation of ~10.0 GPa. The symmetrization pressure obtained by MD simulation is related to T by P （GPa） = 13.9 （GPa） ＋ 0.01 （GPa/K） x T （K）. We conclude that 6-AIOOH in the lower mantle exists with symmetric hydrogen bond from its birthplace, or someplace slightly deeper, to the core-mantle boundary （CM13） along cold subducting slab geotherm, The bulk modulus decreases with T and increases anomalously upon symmetrization： Ko （GPa） = 181 （GPa） - 0,013 （GPa/K） x T （K） for 6-AIOOH with asymmetric hydrogen bond, and Ko （OPa） = 216 （GPa） - 0.013 （GPa/K） × T （K） for 6-AIOOH with symmetric hydrogen bond. Our results provide an important insight into the existent form and properties of 6-AIOOH in the lower mantle.

ADSORPTION OF PHENOL IN NON-AQUEOUS SYSTEM BASED ON HYDROGEN-BONDING

Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was studied. The differential adsorption heats for varied adsorption capacities calculated from the adsorption isotherms according to the Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). The adsorption capacity of o-nitrophenol in cyclohexane was much less than that of phenol under the same condition. The adsorption capacity of phenol from cyclohexane onto polyacrylonitile was much less than that onto poly(p-nitrostyrene) or poly(p-vinylbenzyl amide). All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide) is based on hydrogen-bonding.

Density functional study on chirospectra of hydrogen-bonded systems X^-(H_2O)_3(X=F,Cl,Br,I)

This paper calculates the molecular structures, infrared, Raman, circular dichroism spectra and optical rotatory powers of some hydrogen-bonded supramolecular systems as a cyclic water trimer, （H2O）3 and its pyramidal halide complexes, X- （H2O）3 （X= F, Cl, Br, I） with the gradient-corrected density functional theory method at the B3LYP/6- 311＋＋G（2d,2p） and B3LYP/Aug-cc-pVTZ levels. It finds that the complexation of halide anions with the water trimer can efficiently modulate the chirally optical behaviors. The calculated vibrational circular dichroism spectrum illuminates that the vibrational rotational strength of S（＋） （H2O）3 mostly originates from the O-H rocking modes, whereas chirality of S（-）-X-（H2O）3 （X = F, Cl, Br, I） has its important origin in the O-H stretching modes. The calculated optical rotatory power demonstrates that S（＋） （H2O）3 and S（＋）-F-（H2O）3 are positively chiral, whereas S（-）-X-（H2O）3 （X=Cl, Br, I） are negatively chiral. With the polarizable continuum model, calculated bulk solvent effect in the solvents water and carbontetrachloride and argon shows that the positive chirality of S（＋）-（H2O）3 is enhanced and the negative chirality of S（-）-X-（H2O）3 （X=Cl, Br, I） and the positive chirality of S（＋）-F-（H2O）3 are reduced with an augmentation of the solvent dielectric constant.

Effects of Hydrogen-bonding Interaction and Polarity on Emission Spectrum of Naphthalene-Triethylamine in Mixed Solvent

The effects of the protic and aprotic polar solvents on the emission spectrum of the naphthalene-triethyl-amine system in THF were studied under conditions of steady-state illumination. The fluorescence spectrum of the naphthalene-triethylamine system consists of two emission bands, the fluorescence band of naphthalene(band A, 329 nm) and the emission band of the exciplex(band B, 468 nm). The intensities of both the emission bands decrease with increasing the solvent polarity. The intensity of band B also decreases due to the hydrogen-bonding interaction between triethylamine and protic solvent, while that of band A increases. It is thus suggested that the quenching of naphthalene fluorescence by triethylamine in THF occurs through the charge transfer and electron transfer reactions. The spectral changes upon the increase of solvent polarity can be explained by the dependences of the equilibrium constant between exciplex and ion-pair and the rate constant for the electron transfer reaction from triethylamine to the excited naphthalene on the relative permittivity of solvent. It is shown that the formation of intermolecular hydrogen-bonding between triethylamine and protic solvent suppresses the quenching reaction by the decrease in free amine. Acetonitrile has only a polar effect and trichloroacetic acid only a hydrogen-bonding(or protonation) effect, while alcohols have both the effects. The effects of alcohols could be separated into the effects of solvent polarity and intermolecular hydrogen-bonding interaction quantitatively.

Hydrogen-bonded 1D and 2D Assemblies of Tetraiso-butyl-resorcin[4]arene in the Crystalline State

X-ray crystal structures of co-crystals involving tetra-iso-butyl-resorcin[4]arene 1 with both acetone and acetonitrile solvents were reported. The component 1?2(CH3)2CO 2 assembles such that the resorcin[4]arene adopts a C2v conformation and the acetone serves as hydrogen bond acceptors, forming a 1D hydrogen-bonded polymer. 2 (C50H68O10) crystallizes in the triclinic, space group P1 with a = 10.0440(7), b = 13.7498(9), c = 17.6374(12) ?, α = 77.726(2), β = 86.733(2), γ = 88.634(2)o, V = 2376.1(3) ?3, Dc = 1.159 g/cm3, and Z = 2. The assembly process of component 1?2CH3CN?H2O 3 yields a 2D hydrogen-bonded polymer formed by intermolecular hydrogen bonds between resorcin[4]arene and water molecules. In the case of component 3, the acetonitrile molecule serves as guest inside the bowl of resorcin[4]arene host. 3 (C48H64N2O9) crystallizes in the monoclinic, space group P2/n with a = 13.7570(18), b = 9.0961(12), c = 19.453(3) ?, β = 103.017(3)o, V = 2371.7(5) ?3, Dc = 1.138 g/cm3, and Z = 2.

Investigation on the Percutaneous Enhancing Permeation Mechanism of Azone for Ketoprofen Based on the Intermolecular Hydrogen-bonding Interaction

The permeation enhancing activity of Azone for ketoprofen through excised cavia skins was investigated using Franz diffusion cell. The possible hydrogen-bonded complexes formed between ketoprofen and the model molecule of Azone as azacyclopentane-2-one were fully optimized at the B3LYP/6-311＋＋G＊＊ level. The intermolecular hydrogen-bonding interactions were calculated using the B3LYP/6-311＋＋G＊＊, B3LYP/6-311＋＋G（2df, 2p）, MP2（full）/6-311＋＋G＊＊ and MP2（full）/6-311＋＋G（2df, 2p） methods, respectively. The results show that the steady-state permeation rate of ketoprofen through excised cavia skins enhances over 9 times in the solvent with 2% Azone as compared with the solvent without Azone. The stable O–H…O=C and N–H…O=C hydrogen-bonded complexes could exist between azacyclopentane and ketoprofen. The hydrogen-bonding interaction energy follows the order of（a） 〉（b） 〉（c） 〉（d） 〉（g）〉（e） 〉（h） 〉（f）. The formation of the complexes leads to the change of the conformation and molecular polarity of ketoprofen, and thus causes a better percutaneous permeation for the drug. The analyses of AIM（atom in molecule） and shift of electron density were used to further reveal the nature of the enhancing permeation activity of Azone for ketoprofen. The investigations of the temperature and solvent effects confirm that ketoprofen might enter into the skin by means of the Azone complex.

Estimation of Intramolecular Hydrogen-bonding Energy via the Substitution Method

The intramolecular hydrogen-bonding energies for eighteen molecules were calculated based on the substitution method, and compared with those predicted by the cis-trans method. The energy values obtained from two methods are close to each other with a correlation coefficient of 0.96. Furthermore, the hydrogen-bonding energies based on the substitution method are consistent with the geometrical features of intramolecular hydrogen bonds. Both of them demonstrate that the substitution method is capable of providing a good estimation of intramolecular hydrogen-bonding energy.

One-dimensional Hydrogen-bonded Polymer Based on Tetra-iso-butyl-resorcin[4]arene and 2,6-Diacetylpyridine

The co-crystallization of tetra-iso-butyl-resorcin[4]arene 1 and 2,6-diacetyl- pyridine (Ac2py) from MeCN/CH2Cl2 yielded a multi-component complex 1?Ac2py?2H2O?0.5Me- CN 2, in which the upper rim of 1 is extended supramolecularly by way of hydrogen bonds. Complex 2 (C52H66.5N1.5O14) crystallizes in monoclinic, space group P21/m with a = 10.845(9), b = 20.805(17), c = 12.881(11) ?, β = 103.884(19)o, V = 2821(4) ?3, Dc = 1.102 g/cm3 and Z = 2. The molecular structure shows that the two adjacent double-stranded arrays as well as linear and zigzag chains generated from Ac2py and water bridging to two resorcin[4] arene molecules, respectively, facilitate self-inclusion of one-dimensional hydrogen-bonded polymer.

Hydrogen-bonded Intramolecular Charge Transfer Excited State of Dimethylaminobenzophenone using Time Dependent Density Functional Theory

Density functional theory and time-dependent density-functional theory have been used to investigate the photophysical properties and relaxation dynamics of dimethylaminobenzophe- none （DMABP） and its hydrogen-bonded DMABP-MeOH dimer. It is found that, in non- polar aprotic solvent, the transitions from So to S1 and S2 states of DMABP have both n→π and π→π＊ characters, with the locally excited feature mainly located on the C=O group and the partial CT one characterized by electron transfer mainly from the dimethylaminophenyl group to the C=O group. But when the intermolecular hydrogen bond C=O…H-O is formed, the highly polar intramolecular charge transfer character switches over to the first excited state of DMABP-MeOH dimer and the energy difference between the two low- lying electronically excited states increases. To gain insight into the relaxation dynamics of DMABP and DMABP-MeOH dimer in the excited state, the potential energy curves for con- formational relaxation are calculated. The formation of twisted intramolecular charge trans- fer state via diffusive twisting motion of the dimethylamino/dimethylaminophenyl groups is found to be the major relaxation process. In addition, the decay of the Si state of DMABP-MeOH dimer to the ground state, through nonradiative intermolecular hydrogen bond stretching vibrations, is facilitated by the formation of the hydrogen bond between DMABP and alcohols.

Two New Inclusion 1,4-Butylenediphosphonates with 3D Hydrogen-bonded Frameworks

Two new inclusion 1,4-butylenediphosphonates with three-dimensional hydrogen- bonded frameworks have been synthesized and determined by single-crystal X-ray diffraction. In compound 1, the two-dimensional cationic substructures interpenetrate into the anionic framework, and in compound 2, the cations are encapsulated in the three-dimensional framework. Crystal 1 (C14H24N2O8P2) belongs to triclinic, space group P?with a = 9.4645(2), b = 9.6490(2), c = 11.9479(3) ? = 79.7420(10), b = 73.5650(10), = 63.8420(10), V = 937.55(4) 3, Z = 2, Mr = 410.29, Dc = 1.453 g/cm3, m(MoKa) = 0.276 mm-1, F(000) = 432, the final R = 0.0465 and wR = 0.1304 for 3274 independent reflections. Crystal 2 (C18H26N2O10P2) is of monoclinic, space group P21/c with a = 9.7069(12), b = 16.227(2), c = 6.9339(9) ? b = 98.834(3), V = 1079.2(2) ?, Z = 2, Mr = 492.35, Dc = 1.515 g/cm3, m(MoKa) = 0.261 mm-1, F(000) = 516, the final R = 0.0611 and wR = 0.1162 for 1871 independent reflections.

A Theoretical Study on the Hydrogen-bonded Dimers of HNCO Molecules

Ab initio method has been employed to investigate the hydrogenbond between two HNCO molecules. Two types of hydrogen-bondings in HNCO dimers have been found, one type is N-H…O, the other is N-H…N. The latter is a little stabler than that of the former. The stabilization energies of the two types of dimers are estimated to be 13KJ/mol-21KJ/mol.

A Hydrogen-bonded Tubular Structure of Zinc(Ⅱ) and Methyl-3-pyridylcarbamate

A zinc（Ⅱ） compound [ZnCl2（mpcm）2]（1,mpcm = methyl-3-pyridylcarbamate） was prepared by solvothermal reaction and characterized by elemental analysis,IR spectroscopy,TGA and single-crystal X-ray diffraction.The crystal is of monoclinic system,space group P21/n,C14H16ZnCl2N4O4,Mr = 440.58,a = 8.7893（7）,b = 24.978（2）,c = 9.2510（8）,β = 109.318（1）°,V = 1916.6（3）3,Z = 4,θ = 1.63～25.20°,Dc = 1.527 g/cm3,μ = 1.585 mm-1,F（000） = 896,the final R = 0.0255 and wR = 0.0654 for 3080 observed reflections with Ⅰ 〉 2σ（Ⅰ）.The zinc atom is four-coordinated by the pyridyl groups of two mpcm ligands and two chloride ions with a tetrahedral geometry.Two [ZnCl2（mpcm）2] subunits are held together by a pair of hydrogen bonds,forming a 32-membered macrocyclic dimer,which is further extended into a 3D tubular structure via hydrogen bonding.

Syntheses and Crystal Structures of Two New One-dimensional Double Hydrogen-bonding-chain Complexes [Ni(bipy)_2Cl]·ClO_4 and [Zn(bipy)_2Cl]·BF_4

Two new transition metal complexes, [Ni（bipy）2Cl]·ClO4 （bipy = 2,2＇-bipyridine） 1 and [Zn（bipy）2Cl]·BF4 2, have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 crystallize in monoclinic space group P21/n with Z = 4. For 1, a = 10.776（1）, b = 12.067（1）, c = 16.146（2）A, β = 93.021（2）o, V = 2031.9（4） A^3, Mr = 505.98, Dc = 1.654 g/cm^3, μ = 1.255 mm^–1, F（000） = 1032, the final R = 0.0406 and wR = 0.1002 for 3983 observed reflections with Ⅰ 〉 2σ（Ⅰ）. For 2, a = 10.758（4）, b = 12.058（4）, c = 16.135（5） A, β = 104.57（1）o, V = 2025.7（12） A^3, Mr = 500.00, Dc = 1.639 g/cm^3, μ = 1.396 mm^–1, F（000） = 1008, the final R = 0.0470 and wR = 0.1237 for 3759 observed reflections with Ⅰ 〉 2σ（Ⅰ）. The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. A one-dimen-sional zigzag double hydrogen-bonding-chain is generated by the intermolecular M-bipy ···anion···bipy- M hydrogen bonding interactions between the chelating ligands of bipy and anion.