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A multifunctional thiophene-based covalent triazine framework (TTPATTh) with triphenylamine as core is synthesized by Friedel–Crafts reaction of cyanuric chloride with thienyl derivative for the first time. The yield of TTPATTh (99.59%) is far higher than that of the carbazole-based CTF (TTPATCz, 47.03%). TTPATTh and TTPATCz possess high BET surface areas with 1235 and 2501 m2 g–1 as well as high pore volumes with 1.60 and 2.23 cm3 g–1, respectively. TTPATTh and TTPATCz have high thermal stability with high thermal decomposition temperatures of 514 and 598 °C in nitrogen atmosphere. With the introduction of triazine rings, the fluorescence sensing sensitivities of TTPATTh and TTPATCz to picric acid and iodine are improved significantly. Especially for TTPATTh, the Ksv values reach 5.95 × 105 and 1.61 × 104 L mol–1, and LODs reach 1.02 × 10–12 and 1.86 × 10–12 mol L–1. To the best of the knowledge, this is the most sensitive value among thiophene-based porous organic polymers to PA and I2. Furthermore, TTPATTh and TTPATCz can also adsorb iodine in vapor phase, cyclohexane solution and aqueous solution, and release iodine by heating or in ethanol solution. The efficiency of controlling the release of iodine is higher than that in ethanol. 相似文献
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运用荧光和紫外光谱法并结合分子模拟技术研究了人体生理条件下苦味酸(Picric acid,简称PA)与牛血清白蛋白(BSA)的结合作用。实验结果表明,苦味酸对BSA的荧光猝灭作用较强,该猝灭属于生成复合物的静态猝灭。根据实验结果求得了不同温度下苦味酸与牛血清白蛋白结合作用的结合位点数和结合常数。根据van’t Hoff方程计算出的热力学参数,确定它们之间的相互作用力由以氢键和范德华力为主转变为以疏水作用力为主。根据Foster非辐射能量转移理论,求得苦味酸在距色氨酸残基距离3.14nm的位置与BSA结合。三种探针竞争标记药物实验表明,苦味酸主要结合在BSA上site I位点,分子模拟证实了该结合位点。同步荧光光谱结果表明苦味酸的加入使BSA的构象发生了变化。 相似文献
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苦味酸氨基脲盐的制备与分子结构的研究 总被引:2,自引:2,他引:0
研究了苦味酸氨基脲盐的制备方法 ,并用元素分析、IR、DSC和X射线衍射对其进行了结构表征。其分子式为 :(H2 NCONHNH3 ) + [C6H2 (NO2 ) 3 O ] -。晶体属于三斜晶系 ,P墿的空间群 ,晶体学参数为 :a =5 .0 2 4(1) ,b =10 .2 0 9(1) ,c =11.5 5 1(1) ;α =79.0 0 (1)° ,β =81.11(1)° ,γ =82 .47(1)° ;V =5 71.42 (14 ) 3 ,Z =2 ,Dc=1.768g·cm-3 ,μ =0 .162mm-1,F(0 0 0 ) =3 12 ,R1=0 .0 3 2 4,Rw2 =0 .0 874 相似文献
4.
Gerard M O'Brien Christopher C Wheatley Carlos Iglesias Nigel H Poulter 《Journal of the science of food and agriculture》1994,65(4):391-399
Two rapid semi-quantitative assays for total cyanogens in cassava were evaluated. These were the well-known rapid picrate paper test, and a recently proposed rapid paper test involving the reagent tetra base (TB, 4,4′- methylenebis-(N, N-dimethylaniline)). A precise colorimetric assay was used as a control in the evaluative work. After primary evaluation, both assay methods underwent some modification regarding the interpretation of sample scores. As a result, the reliability of the picrate assay was greatly improved. The TB assay was modified in the interests of safety. Evaluation of this assay over a range of temperatures between 20 and 35°C showed no significant temperature effects upon performance when the new scoring interpretation system was used. The level of endogenous linamarase activity in the sample was found to be an influential factor in rapid assay performance. In a series of comparative trials in three distinct ecosystems, the newly modified picrate assay produced correct results in 68% of cases. This compared with 66% of results correct in the TB assay. It was observed that the TB assay performed more reliably with low cyanogen samples, whilst the picrate assay was more reliable with intermediate cyanogen samples. 相似文献
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咪唑苦味酸盐C3N2H5+C6N3O7H2^-的合成、晶体结构和量子化学 总被引:1,自引:1,他引:0
利用咪唑的醇溶液与苦味酸的醇溶液合成了咪唑的苦味酸盐C_3N_2H_5~+C_6N_3O_7H_2~-,并培养出单晶,通过X射线单晶结构分析法测定了其晶体结构.结果表明,晶体属于正交晶系,空间群为Pbca,晶胞参数为:a=0.895 0 nm,b=1.347 4(3)nm,c=2.016 4 nm,α=β=γ=90°,V=2.431 7(3) nm~3,D_c=1.624 g/cm~3,Z=8,F(000)=1 216.运用Gaussian 03程序,在6-311+G(d)的基组上,用HF和B3LYP两种方法对标题化合物进行了理论研究,并对原子净电荷及原子间布局进行了分析. 相似文献
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苦味酸羧甲基纤维素酯(CMC-PA)是一种对肌酐具有良好吸附性能的新型纤维素衍生物,在前期苦味酸羧甲基纤维素酯(CMC-PA)合成和对肌酐的吸附性能分析的基础上,进一步研究其稳定性以及对维生素B6的吸附性能。在模拟人体生理介质的条件下,采用紫外分光光度法(UV),以358nm为测定波长,分析了pH、水解时间以及放置时间对CMC-PA稳定性的影响;以303nm为测定波长,测定了在不同吸附时间下CMC-PA对维生素B6的吸附性能。研究结果表明,4~6h在pH分别为1、2、8的缓冲溶液中,CMC-PA的水解率分别为0.47%~0.69%、0.213%~0.226%、1.318%~1.418%,室温下放置2、4、6、8个月后,37℃时对肌酐的吸附容量与新制CMC-PA相比没有发生明显的变化。另外,CMC-PA在不同时间条件下,对维生素B6没有明显的吸附。 相似文献
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Yonghao Zheng Mao-sheng Miao Moureen C. Kemei Ram Seshadri Fred Wudl 《Israel journal of chemistry》2014,54(5-6):774-778
We report the first example of a stable pyrenotriazinyl radical, 1,3-diphenyl-1,2,4-pyrenotriazin-4-yl ( PyT ). Magnetic susceptibility measurements of the radical PyT show a transition from a paramagnetic state to an antiferromagnetic state. The pyrene moiety has a strong influence via π π interactions in 1D chain stacks that result in the observed magnetic properties. Unexpectedly, the pyrene unit has essentially no effect on the electronic structure of the triazinyl core. Chemical sensing studies on various nitrophenol-based compounds showed that the radical PyT exclusively senses picric acid ( PA ), as a pH sensor, with a detection limit of 5.0×10−6 M. 相似文献
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ABSTRRACT Three energetic copper (II) complexes, [Cu(1-MAT)2(HDNBA)2](DNBA)2 (1), [Cu(1-MAT)2](PA)2 (2) and [Cu(1-MAT)4(H2O)2](ClO4)2 (3) [1-MAT: 1-methyl-5-aminotetrazole; HDNBA: 3,5-dinitrobenzoic acid; PA: picric acid] were synthesized and characterized. The X-ray single-crystal diffraction results illustrate that the structure of the coordination compounds 1, 2 and 3 belong to the P21/c, P21212 and C2/m space group, respectively. The central copper ion forms a hexacoordinated octahedral structure with N and O atoms. All of them possess good thermal stability, with the thermal decomposition temperatures of 254°C (1), 272°C (2) and 322°C (3), respectively, due to their plenty of coordination bonds, intramolecular and intermolecular H-bonds. According to the results of impact sensitivity and friction sensitivity, these compounds are insensitive to impact (>40 J) and friction (>360 N), except the impact sensitivity of 3 is 2.7 J. The measured constant volume combustion energies of 1, 2 and 3 are 13480, 3537 and 7442 kJ mol?1, respectively. 相似文献
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苦味酸晶体及分子结构的研究 总被引:3,自引:3,他引:0
采用蒸发法制备苦味酸的单晶。用X射线衍射、元素分析、红外光谱对其进行了结构表征。苦味酸晶体属正交晶系 ,Pca2 (1)空间群。晶体参数为 :a =0 .92 6 84(16 )nm ,b =1.913 9(4)nm ,c =0 .9716 (2 )nm ,V =1.72 3 6 (6 )nm3,Z =4,Dc=1.76 6g·cm-3 ,μ =1.6 6cm-1,F(0 0 0 ) =92 8。最终偏离因子R =0 .0 45 4,Rw=0 .0 979。 相似文献