长链烷氧基苯腙衍生物对F-的选择性单一识别

合成了一种长链烷氧基苯腙衍生物受体R,其结构经1H NMR、13C NMR、IR和HR-MS表征。结果表明：通过紫外及裸眼实验分析,受体R在纯DMSO溶液中能够选择性识别F-、Ac-和H2PO4-离子,在5%H2O 95%DMSO体系下可高选择性单一识别F-离子。根据Benesi-Hidebrand方程及Job曲线分析可知,受体R与阴离子形成的络合常数均在3.07 ? 103 L/mol之上,且与F-形成1 : 1型氢键络合物。最后通过1H NMR滴定实验及理论计算阐述了阴离子识别过程机理的可行性。     

氨基脲衍生物的合成及其阴离子识别性能

以3-异氰酸丙基三乙氧基硅烷和2,4-二硝基苯肼为原料,制备了一种氨基脲衍生物阴离子受体R,通过1HNMR、13CNMR、FTIR和HRMS对其结构进行了表征.在二甲基亚砜(DMSO)体系,受体R通过UV-Vis吸收光谱的变化及溶液颜色的显著差别对F–、CH3COO–(Ac–)和CN–表现出良好的识别能力.此外,通过向DMSO体系中加入体积分数30％竞争溶剂H2O可以实现对CN–的单一识别.根据Benesi-Hidebrand方程,受体R识别CN–的络合常数为8.58×103 L/mol,且检出限为1.470μmol/L.Job曲线分析证实,受体R与F–通过氢键以物质的量比为1:1形成配合物.1HNMR滴定及理论计算表明,受体R与阴离子是以氢键形式相结合的识别机制,未发现脱质子过程.     

一种新的氨基硫脲类阴离子受体的合成及其性质研究

合成了一种新的阴离子受体化合物PySN,通过1H NMR对其进行了表征。受体分子结合不同阴离子的紫外-可见光谱和荧光发射光谱变化表明:在非质子性溶剂中,PySN可选择性识别和传感氟离子、醋酸根及磷酸二氢根离子。     

长链烷氧基苯腙衍生物对F–的选择性单一识别

合成了一种长链烷氧基苯腙衍生物受体R,其结构采用1HNMR、13CNMR、FTIR和HRMS进行了表征.结果表明,受体R在纯二甲基亚砜(DMSO)中能够选择性识别F-、Ac-和H2PO4-,在5％H2O+95％DMSO中(体积分数)可高选择性单一识别F-.根据Benesi-Hidebrand方程及Job曲线分析可知,受体R与阴离子形成的络合常数均在3.07×103 L/mol以上,且与F-形成物质的量比为1:1型氢键络合物.最后通过1HNMR滴定实验及理论计算阐述了阴离子识别过程机理的可行性.     

一种偶氮硝基苯脲类阴离子受体的合成及其性质

合成了一种新的阴离子受体,分子结构中同时具有双重结合基团—脲基和氨基及双重变色效应基团—偶氮和硝基,并通过1H NMR对该化合物进行了表征。紫外吸收光谱和荧光发射光谱表明受体分子可选择性识别和传感F-离子,但不具备高的灵敏度。文中并对F-与受体的作用方式进行了探究。     

N-苯甲酰基-N’-苯并噻唑硫脲的合成及其阴离子识别研究

以PEG-400为催化剂,在固液相转移催化条件下,在二氯甲烷溶剂中,以苯甲酰氯、硫氰酸铵和2-氨基苯并噻唑为原料,合成了N-苯甲酰基-N’-苯并噻唑硫脲(化合物1)。该化合物经1HNMR及IR光谱等手段进行了表征。利用UV-Vis和1H NMR测试其对F- 、AcO- 、Cl- 、Br-、I-和H2PO4-等阴离子识别性能。结果表明,该化合物在DMSO溶液中对F-和AcO-表现出明显的选择性识别。1H NMR光谱表明,该化合物1与阴离子之间以氢键相结合,根据摩尔比法得出该化合物与F-阴离子之间形成1:1型氢键缔合物,该化合物与AcO-阴离子之间形成2:1型氢键缔合物。     

离子液体化香豆素基氰离子比色-荧光探针

设计合成了含咪唑鲔盐结构的离子液体化荧光探针分子CCN,其结构用1HNMR及MS进行了表征,考察了其光谱性能。结果表明,在乙腈中,CCN在常见阴离子（F-、C1-、Br-、I-、CH3COO-、HSO4-、H2PO4、CN-）中能够专一性的识别CN-,滴加CN后引起吸收光谱蓝移100nm,溶液颜色由黄绿色变为无色,荧光猝灭21倍,其他阴离子的存在并未干扰CCN对CN-的检测。     

缩酮席夫碱阴离子受体的合成、表征及阴离子识别研究

随着经济与科学技术的发展,阴离子对医药、生命科学、环境保护、农业生产和工业催化等领域的研究有着越来越重要的影响。因此,阴离子识别技术与阴离子受体的设计合成有着广阔的发展前景。合成了3种1,10-邻菲罗琳-5,6-二酮缩(硝基)苯肼席夫碱阴离子受体(R3-1、R3-2和R3-3),应用比色法和紫外-可见吸收光谱法研究了受体分子对阴离子的识别性能。结果表明,受体R3-1、R3-2和R3-3均对阴离子有一定的识别能力,其中R3-3的识别效果最好。分析R3-3的紫外-可见吸收光谱,计算得出R3-3对F~-、Ac O~-和H_2PO_4~-的结合常数Ka分别为6 956(R~2=0.985 9)、4 730(R~2=0.987 3)和3 754(R~2=0.978 7);检出限分别为2.88×10~(-6)mol/L(R~2=0.991 2)、7.7×10~(-6)mol/L(R~2=0.995 3)、1.47×10~(-5)mol/L(R~2=0.992 9)。     

新型酰腙类化合物的合成及阴离子识别研究

设计合成了一种新型的阴离子探针,1-羟基-4-甲基-二苯甲酮对硝基苯酰腙。通过核磁共振谱、质谱和元素分析对其结构进行表征,利用UV-Vis光谱、荧光光谱及1HNMR研究了受体与阴离子如AcO-、H2PO4-、F-、Cl-、Br-和I-的相互作用。结果表明,在不借助任何其他昂贵仪器的情况下,该探针分子在干燥DMSO溶液中能够较好的比色识别F-、H2PO4-和AcO-离子,结合常数表明,该阴离子受体对AcO-具有较高的选择性和荧光响应。最后通过1HNMR滴定进一步研究了1-羟基-4-甲基-二苯甲酮对硝基苯酰腙与阴离子F-的相互作用的本质。     

一种罗丹明结构的汞离子荧光探针的制备及性能

以罗丹明6G和4-溴-1,8-萘二甲酸酐为原料,合成了新型荧光分子探针R6G-NA,通过核磁共振1H NMR、13C NMR和质谱MS等方法对其进行了结构表征。通过荧光光谱及可见光光谱测定,对荧光探针R6G-NA的识别性质进行了研究,结果表明:探针R6G-NA在乙醇-水溶液(p H=7)体系中,与Hg2+作用具有明显的荧光增强响应,在波长550 nm,Hg2+浓度小于90μmol/L的条件下,荧光强度与Hg2+浓度近似呈线性关系,可用于检测水溶性体系中微量Hg2+;在R6G-NA的乙醇-水溶液体系中加入Hg2+,溶液色度的变化可用可见分光光度计进行测量。进行了其他阳离子共存下的竞争试验以及对Hg2+的可逆性试验,结果表明探针R6G-NA对Hg2+具有良好的选择性和可逆性。     

对Fe3+和草酸具有荧光“关-开”功能的喹啉衍生物

通过8-羟基喹啉-2-甲醛与水杨酰肼的缩合反应，合成了一种喹啉席夫碱衍生物荧光分子探针(L)。经FT-IR、1H NMR、13C NMR、ESI-MS表征，确定了探针L的分子结构。利用吸收和荧光光谱研究了探针L的识别性能。在DMSO溶液中，探针L与Fe3+能够形成1:1型配合物L-Fe，表观结合常数为4.6 × 104 L/mol。利用该配合物的形成导致的探针荧光猝灭，能够在常见金属离子中高选择性识别Fe3+，检出限为6.8 × 10-8 mol/L。进一步以L-Fe复合物为探针，实现了对草酸的高选择性荧光增强识别，检出限为1.3 × 10-7 mol/L。该方法可用于蔬菜中草酸的检测。     

DMSO溶液玻璃化过程氢键生命期特性

引言 许多液体被冷却到某个特征温度时,容易结晶,这个温度是熔融温度.这个过程中,首先形成晶核,然后晶体生长,无序的分子排列于是变得高度有序.但是只要超过一定速度降温到另外一个特征温度,液体就能避免结晶,这个特征温度被称为玻璃化温度.随着液体的温度被降到玻璃化温度以下,液体分子还是保留着无序的状态.     

六烯丙基六氮杂异伍兹烷的核磁表征

为精确表征六烯丙基六氮杂异伍兹烷(HAIW)的化学结构,在氘代氯仿(CDCl3)及氘代丙酮(acetone-d6)中研究了HAIW的核磁谱图特征。采用一维及二维1 H、13 C、15 N NMR技术对HAIW的NMR信号进行了全归属,利用核磁模拟软件NMR-SIM对氢谱图进行计算机拟合。结果表明,HAIW在丙酮溶液中的1 H NMR的分辨率较好,谱图中存在两类异伍兹烷信号(环内与桥头)及两类烯丙基碳氢信号,其中五元环所连4个烯丙基不能自由旋转导致亚甲基氢不对称出现2组峰,而六元环所连2个烯丙基则能自由旋转使得该亚甲基氢对称重合;两类烯丙基存在的多种偶合使得氢谱谱线较为复杂;由拟合氢谱化学位移及偶合常数获得的1 H NMR谱图与实际图谱完全一致。表明二维核磁共振技术与核磁模拟技术相结合,可用于对复杂谱的精确分析。     

Effects of salt on homogeneous succinoylation of lignocellulosic fibers in dimethyl sulfoxide/tetraethylammonium chloride under mild condition

Effects of salt in the homogeneous succinoylation of ball milled mulberry wood in dimethyl sulfoxide (DMSO)/tetraethylammonium chloride (TEACl) was investigated using viscometry and two‐dimensional nuclear overhauser effect NMR spectroscopy (2D NOESY). The intrinsic viscosity of mulberry wood solution strongly depends on the TEACl dosage indicating that the change in hydrodynamic size of polymers caused by the interactions between salt and polymers in solution. 2D NOESY spectra reveal that TEA⁺ cations bind to the cellobiose in DMSO by the interactions between methenyl of TEA⁺ and C(1)/C(1′) group of cellobiose and the intensities of the crosspeaks increased with an increase in TEACl dosage. Taking cellobiose as a model compound for cellulose, it can be expected that TEA⁺ cations and cellulose forms a polyelectrolyte‐like complex. The yields of homogeneous succinoylation of mulberry wood in DMSO/TEACl benefits from the interactions between TEA⁺ cations and cellulose evidenced by weight percent gain, Fourier transform infrared spectra as well as CP/MAS ¹³C‐NMR spectra. © VC 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41912.     

Vesicular aggregation and morphologic evolvement of a flexible-rigid block hydrogen-bonding complex

In this paper, we selected a flexible poly(ethylene oxide) (PEO) connected to a stilbazole head group and a semi-rigid dendron of gallic acid with three alkyl chains to prepare an amphiphilic complex through hydrogen bonding. The structure of flexible-rigid complex has been characterized by ¹H NMR, IR and DLS. From the calculation of the binding interaction, the bonded complex occupies ca. 59.5% of total amount of molecules at the molar ratio of 1:1 of its two components, accompanied by the stability constant K_sc about 369 L/mol. The complex displays vesicular aggregation in toluene mixed with a certain amount of DMSO and the structural characterization indicates a symmetrical bilayer with PEO component locating outside towards the solution based on the analysis of contact angle. More interesting, tubular architecture of the complex is observed and found with the similar bilayer structure as that of the vesicular aggregation. The tubules are confirmed to derive from the vesicular aggregation through aging the vesicular structure. It is believed that the present investigation is helpful for the understanding of the dynamics of the vesicle evolvement based on the flexible-rigid complex.     

An NMR study on the DNA-binding SPKK motif and a model for its interaction with DNA

The solution structure of one and two repeats of the ‘SPKK’DNA-binding motif is reported on the basis of NMR measurements.In dimethylsulphoxide (DMSO) the major population (approximately90%) of peptides, SPRKSPRK(S2) and GSPKKSPRK(S2b), adopts aconformation, which has two trans pralines. The two ‘SP(R/K)K’units hi these peptides are equivalent and each adopts a turnstructure exchanging with an extended structure. This is suggestedby an NOE connectivity of the /3-turn type, between the backboneamide protons of residues (j+2) and (j+3) and NOE connectivitiesof the Asx(a)-turn type, between protons of the tth Ser andthe backbone amide proton on residue (i+2). This suggests thateach SP(R/K)K unit has a structural intermediate between (ora combination of) a /3-turn and an Asx(a)-turn. In 90-10% DMSO/H2Oat 4C the two units of S2 are connected more tightly by foldinginto a short 3t0 helix, broken at the second proline. For anotherpeptide, Thr-Pro-Arg-Lys(Tl), the major population (75%) in100% DMSO comprises a /3-turn in rapid exchange with an extendedstructure. We did not observe an NOE connectivity of the Asx()type with the Tl peptide. A possible structure of the SPKK motifhi the complex with DNA is discussed.     

Effect of the solvent on the conformation of a depsipeptide: NMR-derived solution structure of hormaomycin in DMSO from residual dipolar couplings in a novel DMSO-compatible alignment medium

The macrocyclic compound hormaomycin has been investigated by NMR spectroscopy and by restrained molecular-dynamics simulations. Measurement of residual dipolar couplings induced by dissolving the depsipeptide in a polyacrylamide gel compatible with DMSO and their incorporation into the structure calculation of the title compound improved the precision of the family of structures. In DMSO the macrocyclic ring shows two beta-turns, whose positions in the sequence differ from those found in the CDCl3 solution structure and in the crystal structure obtained from hexylene glycol/H2O (50:50). The bulky side chain consisting of a 3-(2-nitrocyclopropyl)alanine and a chlorinated N-hydroxypyrrole moiety is flexible in DMSO.     

PAN基碳纤维纺丝原液的均一性和分散性研究

运用动态流变手段，通过绘制logG′-logG″图和测定体系的凝胶点，对不同温度和非溶剂含量的PAN／DMSO／H2O体系的均一性和分散性进行了研究，并通过凝胶点的测定对体系所处的状态进行了验证。结果表明，当水含量为5％时，体系在60℃～70℃之间由均一液态转变成均一凝胶态；对于水含量不同的其他体系，70℃时均未发生凝胶化转变，依然处于均一的溶液态。通过理论分析，实验采用的常规分子量和较高浓度的PAN溶液均匀稳定，呈现单分散性，是较为理想的纺丝原液。     

3-甲基-1-苯基-5-吡唑酮锌(II)配合物的合成及性质研究

3-甲基-1-苯基-5-吡唑酮(HMPP)与醋酸锌反应得到配合物[Zn2(MPP)2(CH3COO)2]·H2O。通过元素分析、红外光谱、核磁共振氢谱、热重-差热和扫描电镜对配合物的组成和结构进行了表征。用循环伏安法考察了该配合物的电化学行为,发现其电子转移是准可逆的。通过紫外光谱法研究了它与牛血清白蛋白的相互作用,发现二者通过氢键、van der Waals力结合。该配合物对Pb2+的吸附测试结果表明,在40 min内,配合物对25mg/L的Pb2+的吸附去除率达99.74%。