共查询到20条相似文献,搜索用时 46 毫秒
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单猪屎豆碱的2D NMR 总被引:2,自引:0,他引:2
H、13C和DEPT及2DNMR(gCOSY、NOESY、gHSQC和gHMBC)方法,进一步对单猪屎豆碱的核磁共振谱进行了全归属。 相似文献
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A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by 1H NMR, 13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure. 相似文献
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利用三苯基氯化锡和2,6-吡啶二甲酸在三乙胺存在下以1:1摩尔比反应,合成了离子型有机锡化合物{[Ph~2Sn]~2[2,6-Py(CO~2)]~3H~2O}^2^-[HNEt~3]^+~2。通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征。用X射线单晶衍射测定了该化合物的晶体结构。化合物为单斜晶系,空间群P2~1/n,a=1.7073(7)nm,b=1.7447(7)nm,c=2.5333(10)nm,β=109.694(7)°,Z=4,V=6.824(5)nm^3,D~c=1.282g/cm^3,μ=0.793mm^-^1,F(000)=2696,R~1=0.0563,WR~2=0.1539。化合物中两个锡原子呈七配位畸变五角双锥构型。生物活性测试结果表明,该化合物具有较强的体外抗肿瘤活性。 相似文献
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在复杂的天然产物合成和生物合成中,醇醛缩合反应是一类重要的碳-碳键形成反应.不对称催化直接Aldol反应由于其原子经济性,操作简捷,符合绿色化学的要求等,成为近年来不对称合成研究的热点之一. 相似文献
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在合成2-(3-羟基-2-吡啶基)-苯并咪唑的基础上, 利用NMR (1H, 13C, COSY, HSQC 和HMBC), MS, IR 和UV 进
行了详细表征; 通过X-ray 单晶衍射测定该化合物的晶体结构, 实验结果表明该晶体属于单斜晶系{空间群为P21/c,
a=14.289(3) Å, b=10.618(2) Å, c=12.783(3) Å, β=93.51(3)°, V=1935.8(7) Å3, Z=8}, 很好支持了波谱表征的结果.
2-(3-羟基-2-吡啶基)-苯并咪唑的荧光光谱表明, 该化合物在激发态下存在双质子转移现象, 密度泛函计算结果合理解
释了实验现象. 相似文献
行了详细表征; 通过X-ray 单晶衍射测定该化合物的晶体结构, 实验结果表明该晶体属于单斜晶系{空间群为P21/c,
a=14.289(3) Å, b=10.618(2) Å, c=12.783(3) Å, β=93.51(3)°, V=1935.8(7) Å3, Z=8}, 很好支持了波谱表征的结果.
2-(3-羟基-2-吡啶基)-苯并咪唑的荧光光谱表明, 该化合物在激发态下存在双质子转移现象, 密度泛函计算结果合理解
释了实验现象. 相似文献
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Er Fu Huoa Yong Zoua Hui Qin Sunb Yan Huang Zhi Yun Lua Qing Jianga a College of Chemistry.Sichuan University Chengdu China b Analytical & Testing Center Sichuan University China 《中国化学快报》2011,(11)
Three novel conjugated polymers bearing 3,4-bis(4-hexylthiophen-2-yl)-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,~1H NMR and ~(13)C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers... 相似文献
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Sassaki GL Riter DS Santana Filho AP Guerrini M Lima MA Cosentino C Souza LM Cipriani TR Rudd TR Nader HB Yates EA Gorin PA Torri G Iacomini M 《The Analyst》2011,136(11):2330-2338
Recently, oversulfated chondroitin sulfate (OSCS) was identified in contaminated heparin preparations, which were linked to several adverse clinical events and deaths. Orthogonal analytical techniques, namely nuclear magnetic resonance (NMR) and capillary electrophoresis (CE), have since been applied by several authors for the evaluation of heparin purity and safety. NMR identification and quantification of residual solvents and non-volatile low molecular contaminants with USP acceptance levels of toxicity was achieved 40-fold faster than the traditional GC-headspace technique, which takes ~120 min against ~3 min to obtain a (1)H NMR spectrum with a signal/noise ratio of at least 1000/1. The procedure allowed detection of Class 1 residual solvents at 2 ppm and quantification was possible above 10 ppm. 2D NMR techniques (edited-HSQC (1)H/(13)C) permitted visualization of otherwise masked EDTA signals at 3.68/59.7 ppm and 3.34/53.5 ppm, which may be overlapping mononuclear heparin signals, or those of ethanol and methanol. Detailed NMR and ESI-MS/MS studies revealed a hitherto unknown contaminant, tris(2-n-butoxyethyl) phosphate (TBEP), which has potential health risks. 相似文献
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Yong Deng Da Cheng Yang Yi Shen Yu Guo Zhong 《中国化学快报》2007,18(1):7-9
Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides,a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized.The structures were characterized by ~1H NMR,MS and elementary analysis.There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10~(-5) mol/L.Compounds 7a and 7b displayed obvious antiangiogenic activity. 相似文献
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无机离子的核磁共振是研究溶液中分子结构与动力学现象的一种有力工具。~7Li、~(23)Na、~(39)K、~(25)Mg、~(205)Tl NMR等研究所获取的信息,能有助于阐明有关金属离子与小分子、分子膜、蛋白质等之间的相互作用。~(113)Cd核对溶液中的瞬时环境很敏感,但以~(113)Cd NMR研究溶液中Cd~(2+)与配体的配合研究却不多。本文以~(113)Cd NMR研究了在H_2O中Cd~(2+)与18-冠-6(18C6)、12-冠-4(12C)的配合作用;以非线性最小二乘法程序拟合计算出在H_2O中CdSO_4离子对的形成常数;同时,用~(113)Cd NMR测量了两种配体与Cd~(2+)竞争配合物形成常数,这些研究尚未见文献报道。 相似文献
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A number of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines were synthesized.The structures of these new compounds were confirmed by ~1H NMR,IR and elemental analysis.Biological evaluation in the greenhouse showed several compounds have good fungicidal activities at 25 mg/L. 相似文献
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(+)-(1S,2S,5R)-8-联苯薄荷醇的合成 总被引:4,自引:0,他引:4
以(R)-( )-pu legone为起始原料,经1,4-加成,还原两步反应合成了手性辅助试剂( )-(1S,2S,5R)-8-联苯薄荷醇及其差向异构体(-)-(1R,2S,5R)-8-联苯薄荷醇,总产率95%。其结构经1H NMR,13C NMR,IR,MS和X-射线衍射仪表征。 相似文献