Structure Regulation of Electric Double Layer via Hydrogen Bonding Effect to Realize High-Stability Lithium-Metal Batteries

The interfacial chemistry of solid electrolyte interphases(SEI)on lithium(Li)electrode is directly determined by the structural chemistry of the electric double layer(EDL)at the interface.Herein,a strategy for regulating the structural chemistry of EDL via the introduction of intermolecular hydrogen bonds has been proposed(p-hydroxybenzoic acid(pHA)is selected as proof-of-concept).According to the molecular dynamics(MD)simulation and density functional theory(DFT)calculation results,the existence of hydrogen bonds realizes the anion structural rearrangement in the EDL,reduces the lowest unoccupied molecular orbital(LUMO)energy level of anions in the EDL,and the number of free solvent molecules,which promotes the formation of inorganic species-enriched SEI and eventually achieves the dendrite-free Li deposition.Based on this strategy,Li‖Cu cells can stably run over 185 cycles with an accumulated active Li loss of only 2.27 mAh cm^(-2),and the long-term cycle stability of Li‖Li cells is increased to 1200 h.In addition,the full cell pairing with the commercial LiFePO_(4)(LFP)cathodes exhibits stable cycling performance at 1C,with a capacity retention close to 90%after 200 cycles.

Theoretical verification of intermolecular hydrogen bond induced thermally activated delayed fluorescence in SOBF-OMe

Thermally activated delayed fluorescence(TADF)molecules have attracted great attention as high efficient luminescent materials.Most of TADF molecules possess small energy gap between the first singlet excited state(S_(1))and the first triplet excited state(T_(1))to favor the up-conversion from T_(1)to S_(1).In this paper,a new TADF generation mechanism is revealed based on theoretical simulation.By systematic study of the light-emitting properties of SOBF-OMe in both toluene and in aggregation state,we find that the single SOBF-OMe could not realize TADF emission due to large energy gap as well as small up-conversion rates between S_(1)and T_(1).Through analysis of dimers,we find that dimers with intermolecular hydrogen bond(H-bond)are responsible for the generation of TADF,since smaller energy gap between S_(1)and T_(1)is found and the emission wavelength is in good agreement with experimental counterpart.The emission properties of SOBF-H are also studied for comparison,which reflect the important role of H-bond.Our theoretical results agree ith experimental results well and confirm the mechanism of H-bond induced TADF.

Theoretical Investigations into the Intermolecular Hydrogen-bonding Interactions between Azacyclopentane-2-one and N-Methylol Ethanone

The structures of the complexes formed between N-methylol ethanone （model molecule of ceramide） and azacyclopentane-2-one （the model molecule of azone） have been fully optimized at the B3LYP/6-311＋＋G＊＊ level. The intermolecular hydrogen bonding interaction energies have been calculated by 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 strong O-H…O=C, N-H…O=C and C-H…O=C hydrogen bonds could exist between azacyclopentane-2-one and N-methylol ethanone. The formation of the complexes might change the conformation of ceramide molecule and thus cause better percutaneous permeation for the drugs. This is perhaps the origin of the permeation enhances the activity of azone for medicament, as is in accordance with the experimental results. The hydrogen-bonding interactions follow the order of （a） 〉 （c） 〉 （b） 〉 （d） 〉 （g） ≈ （e） ≈ （i） 〉 （h） 〉 （f）. The analyses of frequency, NBO, AIM and electron density shift are used to further reveal the nature of the complex formation. In the range of 263.0- 328.0 K, the complex is formed via an exothermic reaction, and the solvent with lower temperature and dielectric constant is favorable to this process.

Influence of Intermolecular Hydrogen Bonding to Spin Crossover Property of Iron （111） Complexes with a N3O2 Pentadentate Ligand and a Monodentate Ligand

Three iron （III） complexes with the formula of [Feat（X）L2]BPh4 were studied, in which a pentadentate Schiff-base ligand （H2L2 = bis （3-methoxysalicylideneiminopropyl） methylamine） and a counter anion BPh4 were fixed, and three monodentate ligands, 3-Mepy （3-methylpyridine）, 4-NH2py （4-aminopyridine）, and 2-Meim （2-methylimidazole） were used as the axial ligand X. The temperature dependence of magnetic susceptibility measurements demonstrated that [Fem（3-Mepy）L2]BPh4 showed a gradual spin equilibrium between HS （high-spin） （S = 5/2） and LS （low-spin） （S = 1/2） states, [Fem（4-NH2py）L2]BPh4 showed a steep SCO （spin crossover） and [FeIH（2-Melm）L2]BPh4 was in the HS state even at 100 K. The single crystal X-ray analyses demonstrated that [FelH（4-NH2py）L2]BPh4 has an one-dimensional chain structure constructed by intermolecular hydrogen bonding between 4-amino group of 4-NH2py and methoxy oxygen of adjacent molecular-cation. The crystal structure of [FenI（3-Mepy）L2]BPh4 has no such intermolecular interaction and its SCO site behaves independently, and the crystal structure of [FeIII（2-Meim）L2]BPh4 has a NH...n interaction between imidazole group of 2-Meim of cation and a phenyl group of anion BPh4. The result demonstrates that the intermolecular hydrogen bonding affects SCO profile significantly.

Investigation of inter-molecular hydrogen bonding in the binary mixture (acetone+water) by concentration dependent Raman study and ab initio calculations

This paper reports that vibrational spectroscopic analysis on hYdrogen-bonding between acetone and water comprises both experimental Raman spectra and ab initio calculations on structures of various acetone/water complexes with changing water concentrations. The optimised geometries and wavenumbers of the neat acetone molecule and its complexes are calculated by using ab initio method at the MP2 level with 6-311＋G（d,p） basis set. Changes in wavenumber position and linewidth （fullwidth at half maximum） have been explained for neat as well as binary mixtures with different mole fractions of the reference system, acetone, in terms of intermolecular hydrogen bonding. The combination of experimental Raman data with ab initio calculation leads to a better knowledge of the concentration dependent changes in the spectral features in terms of hydrogen bonding.

Density Functional Theory Studies on the Intermolecular Interactions of Five Aza-calix[6]arene Host with HMX

Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed to reveal the origin of the interaction.The intermolecular interaction energy was evaluated with basis set superposition error correction（BSSE） and zero point energy correction（ZPEC）.The B3LYP/6-31G（d） calculations on the five complexes have shown that the greatest interaction（–13.98 kJ/mol） is found in the complex between HMX and hexa-aza-calix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine.The results have indicated that intermolecular interaction energies of aza-calix[6]arenes with substituted group are stronger than those without substituted group,and those with amido are greater than with nitryl.Thus,hexa-azacalix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine is rather equal to eliminate HMX from explosive waste water.

Synthesis and Crystal Structure of Co(DMSO)_2(H_2O)_2(SCN)_2 with One-dimensional Hydrogen-bonded Structure (DMSO = Dimethylsulfoxide)

The title complex Co（DMSO）2（H2O）2（SCN）2 has been prepared and structurally characterized. It crystallizes in monoclinic, space group P21/n with a= 5.1981（9）, b = 11.944（2）, c = 12.646（2） A,β = 98.686（2）°, V = 776.2（2） A^3, C6H16CoN2O4S4, Mr = 367.38, Z = 2, De = 1.572 g/cm^3, F（000） = 378 and μ（MoKa） = 1.646 mm^-1. The structure was refined to R= 0.0232 and wR = 0.0645 for 1241 observed reflections with I 〉 2σ（I）. In the title complex, each Co（II） atom is octahedrally coordinated by four O atoms from two DMSO ligands and two water molecules as well as two N atoms from SCN^- ions. The title molecules are connected to each other through intermolecular hydrogen bonds to form a 1-D structure extended by eight-membered Co2O4H2 rings.

Three New Coordination Polymers Constructed by Adjusting the Angles of Pyridyl or Imidazolyl-based Synthons： Structures and Solid UV-vis Properties

Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-yl） diphenyl ether, bdc2- = 1,3-benzenedicarboxylate）, were characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, IR spectroscopy and TGA analysis.Complex 1 crystallizes in monoclinic, space group P21/n, with a = 9.1568（12）, b = 16.943（2）, c =15.441（2） A, β = 104.049（2）°, V = 2323.9（5） A^3, Dc = 1.420 g/cm^3, Mr = 993.83, F（000） = 1026, μ =0.440 mm-（-1） and Z = 2. Complex 2 crystallizes in monoclinic, space group P21/n, with a =9.1395（17）, b = 17.019（3）, c = 15.473（3） A, β = 104.651（2）°, V = 2328.5（7） A^3, Dc = 1.414 g/cm^3,Mr = 991.58, F（000） = 1024, μ = 0.487 mm^-1, Z = 2. Complex 3 also belongs to the monoclinic system, space group P21/n, with a = 11.4365（16）, b = 18.346（3）, c = 11.7068（17） A, β = 91.022（2）°,V = 2455.9（6） A3, Dc = 1.422 g/cm^3, Mr = 1051.66, F（000） = 1092, μ = 0.468 mm^-1, Z = 2. All complexes 1, 2 and 3 are 2D layer structures constructed from intermolecular hydrogen bonds. In addition, the solid UV-vis properties of complexes 1, 2 and 3 were also studied.

Synthesis and Structure of [Cu(OH)_2(H_2O)_2(4-C_5H_4N-COOH)_2]

The hydrothermal reaction of isonicotinic acid (4-C5H4N-COOH), Cu(ClO4)(2). 6H(2)O and water at 170 degreesC gave the title compound, [Cu(OH)(2)(H2O)(2)(4-C5H4N-COOH)(2)] (1), which was analyzed by single-crystal X-ray diffraction, The complex crystallizes in triclinic space group PY with unit cell parameters: a = 6.337(2), b = 6.894(3), c = 9.178(3). alpha = 99.40(3), beta = 105.26(3), gamma 108.17(5)degrees, V = 354.1(2)Angstrom (3), Z = 1, C12H16CuN2O8, M-r = 379.81, D-c = 1.791 Mg/m(3), F(000) 197, mu (MoK alpha) = 1.589 mm(-1). The final R and wR are 0.068 and 0.170 for 1249 observed reflections with I greater than or equal to2 sigma (I). The central copper ion is in a distorted octahedron geometry completed by two nitrogen atoms from carboxylic ligand, two oxygen atoms from hydroxyl groups and two oxygen atoms from coordinated water molecules. The intermolecular hydrogen bonding leads to the formation of a three-dimensional supramolecular structure.

N,N'-bis(3-Chlorophenyl)urea

The title compound (C 13 H 10 N 2OCl 2, M r = 281.13) was synthesized and its crystal structure was determined by X ray analysis. The crystal belongs to orthorhombic system, space group P22 12 1 with a = 4.589(1), b = 9.725(1), c = 14.385(1), V = 642.0(7) 3, Z =2, D c =1.454Mg·m -3 , F(000) = 288, μ (Mo Kα ) = 0.493mm -1 , final R=0\^0466, wR= 0.1216 for 662 observable reflections with I>2σ(I ). In the crystal of the title compound, the molecule has a crystallographic two fold axis through C(1)-O(1) bond of the carbonyl group. The molecules in the crystal are linked together by a bifurcated N-H…O intermolecular hydrogen bond to form a ribbon extending along the a axis and the aromatic stock effect exists.

Direct Evidence for the Effect of Intermolecular Hydrogen Bonding on Organogels

In order to get direct evidence for the effect of intermolecular hydrogen bonding on the organogels, one arnide group in N-（3, 4, 5-octyloxybenzoyl）-N＇-（4＇-aminobenzoyl）hydrazine（D8） was replaced by a Schiff base group, forming N-（3,4,5-octyloxybenzoyl）-N＇-（4＇-amidobenzoyl） acylhydrazone（T8SchA）. D8 and T8SchA organogels in cyclohexane show the same hexagonal columnar structure. And the hydrogen bonding was demonstrated to be still interacting in the organogels. However, although the molecular geometry of D8 was well retained in T8SchA, the molecular dipole moment of T8SchA is bigger than that of D8 due to the reduction of the number of hydrogen bonds. Thus, the decreased gelling stability of T8SchA compared to that of D8 can only be attributed to the reduction of the number of intermolecular hydrogen bonds, which provides direct evidence that intermolecular hydrogen bonding plays an important role in stabilising organogels.

Solvent Effects on Spectral Property and Dipole Moment of the Lowest Excited State of Coumarin 343 Dye

Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with 4.45 ns in water. This can be ascribed between C343 and hydrogen donating increasing solvent polarity from 3.09 ns in toluene to to the intermolecular hydrogen bonding interactions solvents

Synthesis and Molecular Structure of 5, 5-Dimethyl-2- (4' -methoxy)phenyl-1, 3, 2- thiazaphospholidine-4-thione 2-sulfide

A five-membered phosphoroheterocycle, 5, 5-dimethyl-2-(4 -methoxy)phenyl-1, 3, 2-thiazaphospholidine-4-thione 2-sulfide, has been prepared by the reaction of Lawessons reagent (LR) with -hydroxyl isobutyronitrile, and its crystal structure was determined by X-ray diffraction method. The title compound (C11H14NOPS3) is triclinic with space group P , a= 6.8418 (9), b= 10.5467 (1), c= 11.5670 (2)? = 114.851 (2),β= 100.291 (2),γ= 91.390 (3)? V= 740.7 (2) 3, Z= 2, Dc= 1.360 g/cm3, λ= 0.71073 ? μ(MoK?= 0.59 mm-1, F(000)= 316. The Structure was refined to R= 0.0476, wR= 0.1272 for 2549 unique reflections with I >2σ(I). It contains a phenyl ring and a 5-membered phosphoroheterocycle with the dihedral angle of 87.06 (9)? The five atoms (P (1), N (1), C (1), C (2) and S (2)) of the heterocycle are nearly coplanar. In view of the unit cell it can be concluded that there exists an intermolecular hydrogen bond in the form of Sa┈HN (a: X, Y+1,Z+1). The existence of dpлbond between P (1) and N (1) was found as well as unsaturated property of N (1)C (1) moiety.

New Synthesis and Molecular Structure of 2-(4'-Methoxyphenyl)-2,4-dithia-1,3,2-diazaphospholidine-5,1'-spirocyclohexane

The novel spirophosphoroheterocycle (C14H19N2OPS2, Mr = 326.40) was synthesized by the treatment of Lawesson磗 reagent with amino cyclohexanenitrile, and its crystal structure was analyzed by X-ray diffraction method. The title compound is of monoclinic, space group P21/n with a = 14.296(4), b = 11.028(3), c = 21.715(6) ? ?= 101.823(6), V = 3351.1(2) 3, Z = 8, Dc = 1.294 g/cm3, ?= 0.71073 ? (MoK? = 0.410 mm―1 and F(000) = 1376. The structure was refined to R = 0.0521 and wR = 0.0744 for 5909 observed reflections with I > 2(I). X-ray diffraction analysis reveals that there are three rings in the molecule. The saturated 6-membered ring presents in chair conformation and the 5-membered phosphoroheterocycle is planar. The molecules are found to exist in couples. The existence of d-p?bonds between P and two N atoms and the intermolecular hydrogen bonds are found as well.

Controlling reversible complexation-mediated polymerization(RCMP)via deep eutectic solvents:fast kinetics,narrow molecular weight distribution and mechanistic insights

The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.In this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems.The mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate.Moreover,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity.This investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.

Resolution of racemic R.S-α-arylethylamine by a new resolving agent (R)thiazolidine-2-thione-4-carboxylic acid

Racemic R.S-α-arylethylamine was resolved by R (-) thiazolidine-2-thione-4-carboxylic acid, a new resolving agent abbreviated as [R (-) TTCA], by which R (-) TTCA.S(-) arylethylamine salts2a-2e, [α] D 20 =-47.24° — 64.40° and optically active R(+)-a-arylethylamines3a – 3e, 74. 54%-94. 45% e, e., were obtained. Optically active S (-) -α-arylethylamines4a-4e, 72.84%-90.36% e.e., were obtained by the decomposition of2a-2e in basic solutions. The influence of substitutive group of the benzene ring on the basicity of the amino group was studied by semiempirical PM3 method. The structures of the R (-) TTCA.S (-) -α-phenylethylamine salt (2a(R-S) configuration) and R (-) TTCA-R(+)-a-phenylethylamine salt (2a(R-R) configuration) have been established by means of X-ray diffraction. They crystallize in a monoclinic system. Space group isP21. The cell constants of2a(R-S) configuration were obtained as follows: α = 1.387 8(2), b = 0.664 05(101,c = 1.580 O(2) nm; β = 90.844(10)° Z = 4; those obtained for2a(R-R) configuration were α = 1.080 6(2),b = 0.584 80(12),c = 1.2188(2) nm, β= 110.38(3)dg, V = 0.7220nm3,Z = 2. There are intermolecular hydrogen bonds in the crystals of the two kinds of configurations of the amine salt. The hydrogen bond number in the unit cell of R (-) TTCA.S (-)-α-phenylethylamine salt is twice as much as that of R (-) TTCA.R(+)-a-phenylethylamine salt.

Assembly of Highly Ordered 2D Arrays of Silver-PNIPAM Hybrid Microgels

A strategy was developed for the synthesis of highly ordered 2D arrays of Ag-PNIPAM hybrid microgel. The highly ordered 2D arrays of PNIPAM microgel were prepared by dispersing PNIPAM microgel on a charge-reversible substrate. The microgel spheres self-assembled into a 3D colloidal crystal, and the first 111 plane was fixed in situ onto the substrate as a result of spontaneous charge reversal of the substrate, leaving a high-quality 2D array of PNIPAM microgel. Ag nanoparticles were then synthesized in situ inside the microgel spheres by introduction of Ag＋ ions into the microgel spheres and reduction with sodium borohydride. The resulting 2D arrays are highly ordered. The inter-particle distance in the array can be tuned. In addition, the method allows the synthesis of large size arrays and the use of nonplanar substrate.

A New Route to Z-5-Fluoro-2-methyl-1- （p-methylsulfinylbenzylidene）-3-indenylacetic Acid and Its X-ray Diffraction Analysis

The title compound （Sulindac） was prepared from the corresponding sulfinyl compound p-methylsulfinylbenzyl bromide by four-step reaction. The sole product （Z）-5-fuoror-2-methyl-l-（p-methylsulfinylbenzylidene）-3-indenyl acetic acid （Sulindac） was obtained and the E isomer of it was not found. X-ray single crystal diffraction analysis showed that the strong intermolecular hydrogen bonding and weak intermolecular hydrogen bonding coexisted in Sulindac.