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Structure of [Co(im)6]SiF6:Short Hydrogen Bonds Involving SiF62- Ions
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作者 NAZIR Sadia ARIF Muhammad +1 位作者 RASHID Muhammad Abid WHITWOOD Adrian Charles 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第6期965-970,共6页
A new complex C(18)H(24)CoF6N(12)Si has been synthesized by the reaction of cobalt(II) fluoride tetrahydrate with imidazole in a glass vessel. SiF62-was generated by in situ reaction of fluoride on silica. Thi... A new complex C(18)H(24)CoF6N(12)Si has been synthesized by the reaction of cobalt(II) fluoride tetrahydrate with imidazole in a glass vessel. SiF62-was generated by in situ reaction of fluoride on silica. This complex has been characterized by different techniques such as elemental analysis, IR studies, magnetic measurements, electronic absorption measurements and single-crystal X-ray structure determination. The crystals are hexagonal in the R-3 space group, with a = 13.225(6), b = 13.225(6), c = 12.517(11) A, and g = 120°. In complex [Co(im)6]SiF6, the cobalt atom is six-coordinated to adopt a regular octahedral geometry and the SiF62-ion acts as the counter anion. The crystal displays a network structure and SiF62- bridging hexagram formation by N-(39)···F-Si interactions between imdazole and SiF62-. SiF62-plays an important role in assembling the supramolecular aggregates. 展开更多
关键词 anion binding IMIDAZOLE SiF62- hydrogen bonds transitionmetal fluoride complexes
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The Protective Effects of N-Acetylcysteine on Exogenous Hydrogen Peroxide and Endogenous Superoxide Anion-induced DNA Strand Breakage in Human Spermatozoa
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作者 徐德祥 沈汉民 王俊南 《Journal of Reproduction and Contraception》 CAS 2001年第1期27-33,共7页
Objective To explore the protective effects of N Acetylcysteine (NAC) on exogenous hydrogen peroxide and endogenous superoxide anion induced DNA strand breakage in human spermatozoa by using the single cell gel el... Objective To explore the protective effects of N Acetylcysteine (NAC) on exogenous hydrogen peroxide and endogenous superoxide anion induced DNA strand breakage in human spermatozoa by using the single cell gel electropherosis (SCGE) Methods Sperm cells were exposed to 0.5 mmol/L of H 2O 2 or 5.0 mmol/L of β NADPH with or without 0.1, 0.5, 1.0 mmol/L of NAC. The percentage of sperm comet cells and the comet tail lengths were measured in the treated sperm cells by using SCGE. Results Both percentage of comet sperm nuclei and mean tail length in sperm cells exposed to 0.5 mmol/L hydrogen peroxide with different concentrations of NAC decrease significantly in a dose dependent manner as compared with sperm cells exposed to H 2O 2 without NAC or catalase. Although mean tail length in sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC decreases significantly compared with sperm cells exposed to β NADPH without NAC or SOD, there were no significant differences on the percentage of sperm comet cells between sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC and sperm cells exposed to 5.0 mmol/L of β NADPH without NAC. Conclusion NAC has a protective effect on exogenous hydrogen peroxide induced DNA damage, while protective effect of NAC against O - 2 induced DNA strand breakage is significant but very weak. 展开更多
关键词 N acetylsteine(NAC) SPERMATOZOA DNA hydrogen peroxide (h 2O 2) superoxide anion(O - 2) single cell gel electropherosis (SCGE)
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Synthesis, Bioactivity, and Crystal Structure Analysis of 2-(3-Oxobenzo[d]isothiazol-2(3H)-yl)ethyl Benzoates 被引量:3
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作者 王向辉 游诚航 林强 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第8期1123-1130,共8页
Fifteen novel 2-(3-oxobenzo[d]isothiazol-2(3H)-yl)ethyl benzoates were synthesi- zed by the condensation of 2-(2-hydroxyethyl)benzo[d]isothiazol-3(2H)-one with substituted benzoic acids in dichloromethane. All... Fifteen novel 2-(3-oxobenzo[d]isothiazol-2(3H)-yl)ethyl benzoates were synthesi- zed by the condensation of 2-(2-hydroxyethyl)benzo[d]isothiazol-3(2H)-one with substituted benzoic acids in dichloromethane. All the compounds were characterized by elemental analysis, IR, ESI-MS and 1H NMR. The crystal structures for 2-(2-hydroxyethyl)benzo[d]isothiazol-3(2H)-one (2) and 2-(3-oxobenzo[d]isothiazol-2(3H)-yl)ethyl 2-methoxybenzoate (30) have been determined by X-ray crystal structure analysis. Compound 2 (C9H9NO2S) crystallizes in the monoclinic system, space group Pn with a = 10.552(3), b = 7.849(2), c = 10.765(4) A, β = 103.128(4)°, V= 868.3(5) A3, Mr = 195.24, Dc = 1.493 Mg.m-3, μ = 0.33 mm-1, F(000) = 408, Z = 4, R= 0.0314 and wR= 0.0628. Compound 30 (C17H15NO4S) crystallizes in the triclinic system, space group P1 with a = 8.028(2), b = 9.300(2), c = 10.430(3)A, V= 752.1(3)A3, Mr = 329.36, D,= 1.454 Mg.m-3, p = 0.24 mm-1, F(000) = 344, Z = 2, R = 0.0377 and wR = 0.0904. The preliminary biological test indicated that the title compounds show better growth inhibitory activity against the gram-positive bacteria than the gram-negative bacteria. 展开更多
关键词 2-(3-oxobenzo[d]isothiazoi-2(3h-yl)ethyl benzoates synthesis crystal structure hydrogen bonds
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Synthesis and Crystal Structure of Dichlorobis-(1-methylimidazoline-2(3H)-thione-S) Cobalt(II)
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作者 王玉玲 曹荣 毕文华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第3期303-306,共4页
The reaction of anhydrous cobalt(II) dichloride with 1-methylimidazoline-2(3H)- thione in dichloromethane solution gave the title complex, [Co(C4H6N2S)2Cl2]. X-ray single-crystal analysis revealed that the complex c... The reaction of anhydrous cobalt(II) dichloride with 1-methylimidazoline-2(3H)- thione in dichloromethane solution gave the title complex, [Co(C4H6N2S)2Cl2]. X-ray single-crystal analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, a = 13.9707(10), b = 10.0435(7), c = 10.3910(6) ?, β = 91.181(3)o, V = 1457.70(17) ?3, Z = 4, C8H12Cl2N4S2Co, Mr = 358.17, Dc = 1.632 g/cm3, μ = 1.813 mm–1, F(000) = 724, the final R = 0.0710 and wR = 0.1224 for 1549 observed reflections with I > 2σ(I). The Co atom is coordinated by two S atoms from two 1-methylimidazoline-2(3H)-thione ligands and two chloride ions in a slightly distorted tetrahedral geometry. The intramolecular classical hydrogen-bonding interactions involving chloride ions and N–H groups of the heterocyclic thione ligands are observed. The offset π-π stacking interactions between the imidazole rings of adjacent molecules with a face-to-face dis- tance of 3.604 ? are found in the packing diagram. 展开更多
关键词 cobalt(II) complex 1-methylimidazoline-2(3h)-thione crystal structure hydrogen bonding π-π stacking interactions
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Cl~–…苯氰…H_2O中阴离子氢键协同效应与芳香性理论研究 被引量:1
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作者 宋慧 李斌 +2 位作者 赵光明 武红娟 龙泽清 《原子与分子物理学报》 CAS CSCD 北大核心 2015年第1期15-25,共11页
本文采用DFT-B3LYP和MP2(full)方法对三聚体Cl–…苯氰…H2O中O/C–H…Cl–阴离子氢键与传统氢键O–H…N和C–H…O之间的协同效应、热力学性质以及芳香性进行了研究.结果表明阴离子氢键O/C–H…Cl–对O–H…N或C–H…O相互作用的影响更... 本文采用DFT-B3LYP和MP2(full)方法对三聚体Cl–…苯氰…H2O中O/C–H…Cl–阴离子氢键与传统氢键O–H…N和C–H…O之间的协同效应、热力学性质以及芳香性进行了研究.结果表明阴离子氢键O/C–H…Cl–对O–H…N或C–H…O相互作用的影响更显著.在线性结构中发生正协同效应,熵变是促进热力学协同效应的主要因素,而在环状结构中发生反协同效应,焓变成为主要因素.在三聚体形成过程中,苯氰环的芳香性是减弱的,而苯氰中π→π*共轭效应是增强的.结果表明,协同效应能Ecoop.分别与Rc(NICS(1)ternary/NICS(1)binary),ΔΔδ(Δδternary-Δδbinary),Rc'((NICS(1)ternary-NICS(1)binary)/NICS(1)binary)和RBDE(C–CN)(BDE(C–CN)ternary/BDE(C–CN)binary)均具有良好的线性关系.同时,AIM的分析也佐证了协同效应的存在. 展开更多
关键词 协同效应 阴离子氢键 热力学协同效应 芳香性 MP2
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2-(2-羟基苯基)-4,5-二苯基咪唑的合成及性能研究
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作者 苏小龙 田梦 +1 位作者 谢莉莉 袁耀锋 《宝鸡文理学院学报(自然科学版)》 CAS 2022年第2期40-46,共7页
目的合成4种2-(2-羟基苯基)-4,5-二苯基咪唑类化合物,并研究其阴离子识别性能。方法通过比较化合物与阴离子结合前后紫外-可见吸收光谱的变化,研究4种化合物识别阴离子的作用机制。结果化合物1和2的N-H键通过氢键作用络合F^(-)后,在318... 目的合成4种2-(2-羟基苯基)-4,5-二苯基咪唑类化合物,并研究其阴离子识别性能。方法通过比较化合物与阴离子结合前后紫外-可见吸收光谱的变化,研究4种化合物识别阴离子的作用机制。结果化合物1和2的N-H键通过氢键作用络合F^(-)后,在318 nm处的吸收峰红移到339 nm,而与H_(2)PO_(4)^(-),AcO^(-),HSO_(4)^(-),Cl^(-),Br^(-)和I^(-)作用后,吸收光谱没有明显变化;化合物3和4与F^(-)结合后,会形成Cu-受体-阴离子三元配合物,导致吸收光谱发生轻微的蓝移,而加入H_(2)PO_(4)^(-),AcO^(-),HSO_(4)^(-)和I^(-)后,会使配合物分解。结论化合物1和2可选择性地识别F^(-)。 展开更多
关键词 咪唑 铜配合物 阴离子识别 氢键
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Reversible Disassembly and Intercalation of 2-Ureido-4[1 H]- Pyrimidinone Quadruple Hydrogen-bonded Supramolecular Assembly by Fluoride and Lead Ions
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作者 俞茂林 赵春常 +3 位作者 冯科 陈彬 佟振合 吴骊珠 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2011年第12期2684-2688,共5页
2-Ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded assembly 1,1 containing N,N-dimethylaminophenyl moiety exhibits a sensitive response to fluoride anion and lead cation. Spectroscopic studies reveal that the prese... 2-Ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded assembly 1,1 containing N,N-dimethylaminophenyl moiety exhibits a sensitive response to fluoride anion and lead cation. Spectroscopic studies reveal that the presence of small amount of fluoride anions and lead cations can easily disassemble and intercalate 2-ureido- 4[ 1H]-pyri mi di none hydrogen-bonded supramolecular architectures. 展开更多
关键词 2-ureido-4[1h]-pyrimidinone assembly hydrogen bonds fluoride anion lead cation self-assembly
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Neutral C–H bond vs. electron pair of N(sp^2): A binding site effect study of macrocycle anion receptor
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作者 Chuan-Cai Fan Li-Jin Xu Han-Yuan Gong 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第8期1125-1131,共7页
To evaluate the effect of neutral C–H bond or electron pair of nitrogen atom with sp2hybridization(N(sp2)) involving into the same chemical environment for anion binding, two analogous tetracationic imidazolium m... To evaluate the effect of neutral C–H bond or electron pair of nitrogen atom with sp2hybridization(N(sp2)) involving into the same chemical environment for anion binding, two analogous tetracationic imidazolium macrocycles, namely cyclo[2](2,6-bis-(1H-imidazol-1-yl)pyridine) [2](1,3-dimethylenebenzene)(14+), and cyclo[2](2,6-bis-(1H-imidazol-1-yl)pyridine)[2](2,6-di methylenepyridine)(24+)were studied in detail as small inorganic anion receptors. The guest anions with different shapes are Cl,N3, NO3, and H2PO4. The host–guest interactions were characterized via1 H NMR spectroscopy,electrospray ionization mass spectrometry(ESI-MS) and single crystal X-ray crystallography. The results implied that macrocyclic hosts with similar backbone but two distinct binding sites(14+with neutral C–H vs. 24+with N(sp2)) vary markedly in their response to anions, including the binding modes and association constants. The finding will serve to the construction of new anion receptors, even improve insights into the anion binding process in biology. 展开更多
关键词 MACROCYCLE anion binding Neutral C-h bond N(sp2) hydrogen bond
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