共查询到18条相似文献,搜索用时 109 毫秒
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基于题示光敏离子载体MMC-MAC(O5)与金属离子配位时荧光或延迟荧光性质的变化,研究了它作为光敏主体在乙腈或水溶液中对Li+,Na+,K+,Mg2+,Ba2+和Pb2+离子的识别性能,由改进的H-B方程计算得主客识别的稳定常数和敏感因子.结果表明,由于该光敏离子载体的香豆素的羰基能以七元环形式参与对金属离子的配位,在一定程度上增大了对客体离子的络合能力;在水溶液中,由于金属离子的溶剂化作用和因香豆素的羰基易与水形成氢键,影响了MMC-MAC(O5)与客体离子的结合,稳定常数明显降低.基于MMC-MAC(O5)的分子结构和与金属离子结合时荧光强度的增强,讨论了识别机理 相似文献
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合成、鉴定了具有离子识别功能的题示光敏离子载体(6,7-二甲氧基-4-亚甲基香豆隆基)单氮杂-18-冠-6(DMC-MAC(O5),研究了它在水中的吸收和荧光光谱,基于不同pH值水溶液中荧光光谱的变化,计算得该试剂激发态分子的酸性常数pKa^*=6.00。基于在不同溶剂中荧光光谱的变化,由Solvachromic法,利用Lippert方程并借助Alchemy2000量化计算软件,采用分子力学模型( 相似文献
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光敏离子载体丹磺酰基-单氮杂-18-冠-6的阳离子识别性质研究 总被引:1,自引:0,他引:1
以DNS-MAC(O5)为主体,利用其荧光性质研究了该物质在乙腈和水溶液中对阳离子Li^ ,Na^ ,K^ ,Mg^2 ,Ba^2 和Pb^2 的识别性质,由改进的B-H方程计算了主-客体配合物的稳定常数和识别敏感因子,结果表明,阳离子的电荷密度和阳离子与冠醚环空间的匹配程度是影响其识别性质的最重要的两个因素,DNS-MAC(O5)与阳离子配位时荧光光谱的变化主要受迭于阳离子的电荷密度,阳离子与DNS-MAC(O5)配位时不仅使这种离子载体的偶极矩增大,而且更有利于其实现光谱导分子内的电荷转移,所以激发态稳定性增加,荧光光谱红移,同时测定也该发光离子载体在乙腈和水中的荧光量子产率。 相似文献
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研究了以2-羟基-4-甲氧基苯甲醛和2-氨基-6-甲基吡啶为原料合成新型席夫碱化合物5-甲氧基-2-[(E)-(6-甲基吡啶-2-亚氨基)甲基]苯酚的方法。当2-羟基-4-甲氧基苯甲醛与2-氨基-6-甲基吡啶摩尔比为1∶1.6,反应时间为6 h,反应温度为75℃时,反应产率最高。采用元素分析、UV-Vis、IR、1H NMR、X-射线单晶衍射等方法进行结构表征。该化合物为单斜晶系,空间群P21/c,a=1.1886(3)nm,b=0.65948(16)nm,c=1.6897(4)nm,β=108.505(3)°,V=1.2560(5)nm3,Dc=1.281 g·cm-3,Z=4,F(000)=512,μ=0.087 mm-1,R1=0.0477,wR2=0.1342。通过π···π堆积和分子内氢键O2-H2···N1、C8-H8A···N2形成较稳定的晶体结构,并具有蓝色荧光。 相似文献
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Katleen Verleysen Jos Vandijck Mark Schelfaut Pat Sandra 《Journal of separation science》1998,21(6):323-331
An overview is presented of the applicability of the crown ether 18-crown-6-tetracarboxylic acid (18C6H4) as buffer additive in capillary electrophoresis (CE) for the separation of enantiomers. The chiral selector 18C6H4 is particularly useful for the separation of racemates having a primary amino function. Unfortunately, the crown ether is no longer commercially available. The synthesis and spectroscopic characterization are therefore described in detail. Moreover, a method is presented for the regeneration of the crown ether after CE application. Some new enantiomeric separations of amino acids i.e. NORLEU, ARG, GLU, m-TYR, and o-TYR are listed and the influence of the pH and temperature of the separation buffer is discussed. An intermediate in the synthetic pathway, namely 18-crown-6-tetracarboxamide, did not exhibit any enantioselectivity in CE. 相似文献
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Xi-ke gao Jian-min dou Da-cheng li Feng-ying dong Da-qi wang 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):111-119
Five novel 2,3-naphtho crown ether group 10 metal bis(dithiolate) complexes, [Na(N15C5)2]2[Pd(mnt)2] (1), [Na(N15C5)]2[Pd(i-mnt)2] (2) and [K(N18C6)]2[M(i-mnt)2] (3
5) (where mnt = 1,2-dicyanoethylene-1,2-dithiolate, i-mnt = 1,1-dicyanoethylene-2,2-dithiolate and M = Ni, Pd, Pt for complexes
3–5, respectively), have been synthesized and characterized by elemental analysis, FT-IR, UV–Visible spectra and single crystal
X-ray diffraction. X-ray diffraction analyses reveal that complexes 1 and 2 have different structural features while complexes 3–5 are structurally isomorphous. Complex 1 consists of two [Na(N15C5)2]+ sandwich complex cations and one [Pd(mnt)2]2− anion, affording a zero-dimensional structure. For 2, the [Na(N15C5)]+ mono-capped complex cations act as the bridges linking the [Pd(i-mnt)2]2− anions into a 1D infinite chain through Na–N interactions and SȮFC and SȮFπ interactions are observed in the resulting chain.
Complexes 3–5 all consist of two [K(N18C6)]+ complex cations and one [M(i-mnt)2]2− (M = Ni, Pd or Pt) anion and the complex molecules are linked into␣1D␣chains by the bridging K–O(ether) interactions between
the adjacent [K(N18C6)]+ units. What’s novel is that the resulting chains are assembled into novel 2D networks through interchain π–π stacking interactions
between the neighboring naphthylene moieties of N18C6. The stack model of naphthylene group in complexes 3–5 is discussed. 相似文献
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IntroductionRecentyears ,coordinationpolymershavebeenre ceivedmuchattentionbecauseoftheirinterestingphysi calpropertiessuchaselectricalconductivity ,mag netism ,nonlinearopticalpropertiesandpotentialappli cationsinseparationandcatalyst.1Themodularap proach… 相似文献
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Ling Tian TANG Yi WANG Xin Qi LIU Shao Wen HU Tai Wei CHU Xiang Yun WANG* College of Chemistry Molecular Engineering Peking University Beijing 《中国化学快报》2005,16(3):345-348
Benzimidazole compounds have attracted a renewed interest recently owing to theirpotential applications in high-performance composite materials, electronic chemicals,photosensitive materials, and their special potentials in biological and/or medicinalapplication1,2. Typically, aromatic compounds with near planar structures and contain-ing hydrogen-donor groups or groups, which are capable of being protonated, havespecial interactions with DNA via intercalation, hydrogen-bonding, and so on3.Me… 相似文献
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以2,4-二氯-6-辛氧基-1,3,5-三嗪为原料,经Kumada偶联及胺化两步反应合成了三嗪胺衍生物:4-(9-蒽基)-6-辛氧基-1,3,5-三嗪-2-胺(AOOTA),总产率为38%.通过紫外-可见吸收光谱及荧光光谱研究了氯仿溶液中AOOTA在乙酸(HOAc)及三氟乙酸(TFA)作用下的光谱行为.研究发现AOOTA与HOAc在基态及激发态下均不能发生双氢键作用,而AOOTA与TFA相互作用基态下形成双氢键复合物,激发态下由于分子中蒽基及辛氧基与三嗪环间的C-C单键以及C-O单键的自由旋转,从而使得AOOTA与TFA分子间不能形成有效的氢键相互作用. 相似文献
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三维网状冠醚配合物(Bu4N){[K(18-C-6)][Cd4(dmit)2(dmt)3]}的合成与结构 总被引:5,自引:0,他引:5
研究了18-冠-6(18-C-6)与KSCN,CdCl2.2.5H2O,(Bu4N2)[Zn(dmit)2] (dmit=4,5-dimercapto-1,3-dithiole-2-thione,C3S5^2-)的反应,生成的标题配 合物(1)通过元素分析,红外光谱,单晶X射线衍射进行了表征,配合物属单斜晶 系,空间群C2/c,晶体学数据:a=3.4780(7)nm,b=1.5170(3)nm,c=2.8440(6)nm,β =105.93(3)°,V=14.427(3)nm^3,Z=8,F(000)=7872,R1=0.0425,wR2=0.0739,配合物 由一个Bu4N^+阳离子和一个{[K(18-C-6)][Cd4(dmit)2(dmt)3]}-(dmt=4,5- dimercapto-1,2-dithiole-3-thione,C3S5^2-)配阴离子组成,{[K(18-C-6)[Cd4 (dmit)2(dmt)3]}-通过K…S,S…S弱相互作用形成三维网状结构。 相似文献
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为了研究正电子核素18F标记的葡萄糖转运蛋白显像剂6-18氟-6-脱氧葡萄糖的制备及在小鼠体内的生物学分布, 以D-葡萄糖为起始原料, 经过丙酮和苯甲醛对1,2,3,5位羟基的定位保护, 然后用对甲苯磺酰氯和6位的羟基反应得到能被18F-进攻的离去基团, 最后用18F-离子通过亲核取代反应实现对葡萄糖6位的氟代标记; 反应中间体用NMR和MS表征, 最终产物用标准品6-19FDG在HPLC下对照确认, 测定放化纯度, 观察其在小鼠体内的生物学分布. 6-18氟-6-脱氧葡萄糖的放射性标记过程需35 min(从加速器轰击结束算起), 放化产率70%±5%(校正后, n=5), 放化纯度>95%. 小鼠体内的生物学分布表明, 各个器官在1.0 min达到峰值, 然后逐渐平衡. 初步研究结果表明, 6-18FDG是一种很有价值的葡萄糖转运蛋白显像剂, 为以后的体内外研究及活体显像奠定了基础. 相似文献