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 electrocataly...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.展开更多
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 interacti...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.展开更多
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 a...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.展开更多
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...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.展开更多
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 lo...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.展开更多
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 th...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.展开更多
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 pyramid...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.展开更多
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 adop...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.展开更多
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 molecul...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.展开更多
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 meth...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.展开更多
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 su...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.展开更多
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 li...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.展开更多
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 c...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.展开更多
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 ...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.展开更多
Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co(en)312[Zr2(C2O4)7]·2H2O (1) has been obtained. The title complex crystall...Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co(en)312[Zr2(C2O4)7]·2H2O (1) has been obtained. The title complex crystallizes in the monoclinic, space group P21/n (No. 14) with a = 7.7448(10), b = 14.5683(19), c = 19.375(3) A, fl = 92.124(2)°, V= 2184.5(5) A3, Z = 4, Dc = 1.996 gcm-3, F(000) = 1332, μ = 1.328 mm"1, R = 0.0353 and wR = 0.0718 (1 〉 2α(I)). Single-crystal structure analysis reveals that the title complex possesses a 3D network assembled through a multitude of charge-assisted hydrogen bonds between the in situ generated anionic coordination complexes [Zr2(C204)7]6- and metal complexes Co(en)33+.展开更多
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)-pipera...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 by1H 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.展开更多
Two series of novel cholesteryl-containing H-bonded liquid crystals were prepared through facile self-assembly between cholesteryl isonicotinate (proton acceptor) exhibiting a monotropic cholesteric phase, and the 4...Two series of novel cholesteryl-containing H-bonded liquid crystals were prepared through facile self-assembly between cholesteryl isonicotinate (proton acceptor) exhibiting a monotropic cholesteric phase, and the 4-alkoxy-benzoic acid or 4-alkoxy cinnamic acid (proton donor). It was found that the increase of the conjugate length as well as the terminal length can contribute to enhance the interaction of molecules and thus significantly influenced the thermal behaviors of H-bonded LCs. The cholesteric reflection spectra of the induced mesogenic complexes were located in the visible region with the color tuneable thermo-sensitivity, which could be used for display application.展开更多
The title compound, [Pd(2,2′-bipy)2](Haadip)2·4H2O, was synthesized via the hydrothermal reaction of PdCl2 with 5-aminodiacetic isophthalic acid (H4adip) in an acetic acid water solution. It was characteri...The title compound, [Pd(2,2′-bipy)2](Haadip)2·4H2O, was synthesized via the hydrothermal reaction of PdCl2 with 5-aminodiacetic isophthalic acid (H4adip) in an acetic acid water solution. It was characterized by elemental analysis and infrared spectrum. Crystal data for C44H44N6O20Pd: monoclinic, space group P21/n, a = 11.0674(2), b = 9.9716(2), c= 20.5770(3)A, β = 92.7300(3)°, V = 2268.29(7)A^3, Z = 2, Mr = 1083.25, Dc = 1.586 g/cm^3, F(000) = 1112,μ = 0.499 mm^-1, 2(MoKa) = 0.71073 A, T = 293(2) K, 2θmax = 51.38°, GOOF = 1.067, R = 0.0268 and wR = 0.0710 for 3770 reflections with 1 〉 2σ(I). X-ray diffraction studies reveal that the title compound has an interesting 3D microporous architecture via hydrogen bonds with the cations located inside the channel.展开更多
基金financial support from the National Key R&D Program of China(Grant 2022YFA1504000)the National Natural Science Foundation of China(Grants 22125205,22002166,22272176,22072146 and 22002158)+2 种基金the Fundamental Research Funds for the Central Universities(20720220008)the Dalian National Laboratory for Clean Energy(DNL202007,DNL201923)the financial support from the CAS Youth Innovation Promotion(Grant Y201938)。
文摘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.
基金supported from the Natural Science Foundation of Shanxi Province(2009011014)
文摘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.
基金We are gratefully acknowledged financial support of this work by the National Natural ScienceFoundation of China (2007 1034) the N.S.F of Guangdong Province of China.
基金Supported by the National Natural Science Foundation of China(No.2 0 1710 10)
文摘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.
文摘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.
基金Supported by the National Natural Science Foundation of China under Grant Nos U1232204,41473056,11422431 and 11634001the National Key Research and Development Program of China under Grant No 2016YFA0300901the National Basic Research Program of China under Grant No 2013CB934600
文摘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.
文摘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.
基金Project supported by the Scientific Foundation of Education Department of Yunnan Province of China (Grant No. 07Z11621)the Innovation Foundation for New Researchers in Dali University (Grant No. KY421040)the National Natural Science Foundation of China (Grant No. 20573114)
文摘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.
基金This project was supported by the Key Scientific Research Foundation of State Education Ministry of China (No. 204067)
文摘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.
基金Supported by Natural Science Foundation of Shanxi Province(No.2012011007-5)the application and innovation project in police(No.2011YYCXSXST016)
文摘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.
基金the National Natural Science Foundation of China (No. 20573049)
文摘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.
文摘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.
文摘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.
基金Supported by the National Natural Science Foundation of China (No. 20872149)
文摘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.
基金This work was supported by the National Natural Science Foundation of China (No. 20471026)Natural Science Foundation of Henan Province (No. 0511022600)
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.21301024,21103017)the Fundamental Research Funds for the Central Universities(N120305003)
文摘Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co(en)312[Zr2(C2O4)7]·2H2O (1) has been obtained. The title complex crystallizes in the monoclinic, space group P21/n (No. 14) with a = 7.7448(10), b = 14.5683(19), c = 19.375(3) A, fl = 92.124(2)°, V= 2184.5(5) A3, Z = 4, Dc = 1.996 gcm-3, F(000) = 1332, μ = 1.328 mm"1, R = 0.0353 and wR = 0.0718 (1 〉 2α(I)). Single-crystal structure analysis reveals that the title complex possesses a 3D network assembled through a multitude of charge-assisted hydrogen bonds between the in situ generated anionic coordination complexes [Zr2(C204)7]6- and metal complexes Co(en)33+.
基金Project(50573019)support by the National Natural Science Foundation of China
文摘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 by1H 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.
基金supported by National Natural Science foundation(No.20674005)Program of National High Technology 863 program of China(No.2006AA03Z108)Science and Technology Program of Beijing,China (No.Y0405004040121)
文摘Two series of novel cholesteryl-containing H-bonded liquid crystals were prepared through facile self-assembly between cholesteryl isonicotinate (proton acceptor) exhibiting a monotropic cholesteric phase, and the 4-alkoxy-benzoic acid or 4-alkoxy cinnamic acid (proton donor). It was found that the increase of the conjugate length as well as the terminal length can contribute to enhance the interaction of molecules and thus significantly influenced the thermal behaviors of H-bonded LCs. The cholesteric reflection spectra of the induced mesogenic complexes were located in the visible region with the color tuneable thermo-sensitivity, which could be used for display application.
基金supported by 973 Program (2006CB932900)National Natural Science Foundation of China (No. 20571074 and 20521101)
文摘The title compound, [Pd(2,2′-bipy)2](Haadip)2·4H2O, was synthesized via the hydrothermal reaction of PdCl2 with 5-aminodiacetic isophthalic acid (H4adip) in an acetic acid water solution. It was characterized by elemental analysis and infrared spectrum. Crystal data for C44H44N6O20Pd: monoclinic, space group P21/n, a = 11.0674(2), b = 9.9716(2), c= 20.5770(3)A, β = 92.7300(3)°, V = 2268.29(7)A^3, Z = 2, Mr = 1083.25, Dc = 1.586 g/cm^3, F(000) = 1112,μ = 0.499 mm^-1, 2(MoKa) = 0.71073 A, T = 293(2) K, 2θmax = 51.38°, GOOF = 1.067, R = 0.0268 and wR = 0.0710 for 3770 reflections with 1 〉 2σ(I). X-ray diffraction studies reveal that the title compound has an interesting 3D microporous architecture via hydrogen bonds with the cations located inside the channel.