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1.
合成了携带有丹磺酰基荧光团和(1R,2R)- 或(1S,2S)-1,2-二苯基乙二胺键合单元的双臂杯[4]芳烃手性阴离子受体(1和2)。通过荧光光谱检测了受体对手性氨基酸阴离子的键和能力。非线型曲线拟合的结果表明受体(1或2)与N-乙酰基-L或D-天冬氨酸盐通过多重氢键的相互作用形成了1:1的络合物。并且展现了对N-乙酰基天冬氨酸盐对映体良好的对映选择性的荧光识别(受体1: Kass(D)/ Kass(L)=6.74;受体2: Kass(L)/ Kass (D)=6.48)。明显不同的荧光响应说明受体1和2能被用作为对N-乙酰基天冬氨酸盐的荧光化学传感器。  相似文献   

2.
N-硝基脲类的合成及其阴离子识别研究   总被引:1,自引:0,他引:1  
合成了两种新型的阴离子识别受体N-硝基-N-(2,6-二硝基-4-三氟甲基苯基)-N'-(4-氯苯基)脲(受体1)和N-硝基-N-(2,6-二硝基-4-三氟甲基苯基)-N'-(4-甲基苯基)脲(受体2).利用紫外-可见吸收光谱考察了其与F-、Cl-、Br-、I-、H2PO4-、HPO42-、PO43-阴离子客体的识别作用.结果表明:在受体分子中加入F-、H2PO4-、HPO42-阴离子,其紫外-可见吸收光谱发生明显变化且溶液颜色由黄色变为紫色,而加入其他离子时无此现象.从而实现对这3种阴离子的裸眼检测.测定了结合物的结合比及结合常数.Job工作曲线表明受体与阴离子客体形成了1:1结合物.结合常数表明:同一受体对不同阴离子的选择性不同,受体分子1选择性HPO42- > H2PO4 > F-,受体分子2选择性HPO42- > F- > H2PO4;受体分子与同一阴离子客体的结合能力呈现规律性,1>2.提出了可能的结合模式.  相似文献   

3.
设计合成阴离子受体是近年来超分子化学中一个颇为活跃的研究领域[1~ 7] .其中荧光法以其高灵敏度和高选择性等特点使发光受体的设计合成备受关注 [6 ,7] .分子内电荷转移 (Intramolecular charge transfer,ICT)原理已被成功地用于构筑阳离子荧光传感体系[8] ,但将其应用于阴离子识别的研究尚鲜见报道[9~ 12 ] .本文设计合成了 ICT荧光体对二甲氨Scheme 1  The structures of anion receptors基苯甲酰肼 (DMABH,结构见 Scheme 1 ) ,研究了 DMABH与阴离子如 HSO- 4,Ac O- ,H2 PO- 4,Cl O- 4,NO- 3,Cl- 和 Br- 等结合后的光…  相似文献   

4.
苯甲酰氨基脲的合成及其阴离子识别   总被引:1,自引:0,他引:1  
聂丽  李爱芳  江云宝 《化学学报》2009,67(6):564-568
设计合成了N-(取代苯甲酰氨基)脲衍生物(取代基=p-OC2H5, H, p-Cl) 1~3, 应用吸收光谱法考察了受体分子与阴离子如 , F-, 等的相互作用, 考察了取代基对受体分子与阴离子亲合力和结合选择性的调控或改善能力. 结果表明, 该类受体分子与阴离子通过氢键形成阴离子配合物, 乙腈中受体分子1对F-表现出极高的响应选择性. Job作图法表明1与F-的结合计量比为1∶1, 1H NMR滴定结果为受体分子与阴离子间的氢键作用本质提供了直接证据, 初步探讨了F-响应选择性的原因.  相似文献   

5.
张峰  谭赞  闫柏任  潘顶伍  鲍小平 《有机化学》2014,(12):2499-2504
设计合成了一个新型的含1,8-萘酰亚胺信号单元的咔唑磺酰肼类阴离子受体1,荧光和UV-vis光谱滴定实验表明,1在DMSO中能选择性识别具有重要生物学意义的F-,Ac O-和2 4H PO-;受体1与这些阴离子形成1∶1的配合物,且它们的结合常数均大于103 L?mol-1.有趣的是,在含水10%(V/V)的DMSO中1对F-表现出了专一性识别.DMSO-d6中的核磁滴定表明,在F-浓度较低时,受体1通过五重分子间氢键作用与其产生了有效结合.  相似文献   

6.
设计合成了含氨基蒽醌信号单元的咔唑磺胺类阴离子受体L,通过~1H NMR、~(13)C NMR、MS、IR和元素分析对其结构进行了表征.UV-Vis与荧光光谱滴定实验表明,在二甲基亚砜(DMSO)中L对F-表现出了高选择性识别并与之形成了1∶1型氢键配合物.此外,F-诱导受体L的荧光出现明显猝灭且使受体溶液由红色变为紫红色,表明L可同时作为F-的荧光和比色传感器加以使用.  相似文献   

7.
合成了4种N-(2,4-二硝基苯基)-N -取代苯腙类阴离子结合受体(14, 取代基 R=H, o-OCH3, o-Cl, o-OH), 应用紫外吸收光谱方法研究了其与阴离子的相互作用, 以及考察N -苯环取代基对受体分子之阴离子亲合力和选择性的影响. 实验显示: 乙腈中F、CH3CO 等阴离子使受体分子吸收光谱红移, 溶液由黄色转变为红色, 其中受体分子2对 F表现出高选择性的灵敏响应. 实验表明受体-阴离子间形成了氢键型超分子配合物, Job作图法给出了受体分子与阴离子的1∶1结合计量比, 1H NMR滴定为受体分子与阴离子间的氢键作用本质提供了直接证据.  相似文献   

8.
设计合成了用于识别阴离子的荧光传感分子水杨醛缩苯乙酰腙(1),通过红外光谱、核磁共振谱和质谱表征其结构;利用其光谱性质研究了该物质对几种阴离子的识别性质,初步探讨了其结合模式。实验表明:在乙腈介质中,受体分子1表现出对F-良好的选择性,F-的加入导致1在478 nm处荧光增强44倍,而其它阴离子只引起1的荧光略微增强,Job法实验得出1与F-的结合比为1∶1。  相似文献   

9.
以β-萘酚为原料,经过多步反应合成了5种不同电子效应的1-(5,6-苯并香豆素-3-甲酰基)-4-芳基氨基硫脲衍生物,并通过1H NMR,13C NMR,IR及元素分析等测试手段对受体分子进行表征.利用紫外-可见吸收光谱和荧光光谱考察了这类受体分子与F-,Ac O-,C1-,Br-,I-,HSO4-等阴离子的作用,发现受体分子对其它阴离子无响应;而对F-和Ac O-离子具有良好的选择性检,检测限分别为5.45与7.00μg/L,响应时间分别为5与10 min.实验结果表明该类受体分子与阴离子通过氢键形成配位物,从而导致光谱信号的变化.通过主客体间结合比和稳定常数的计算,证实了受体分子对F-和Ac O-选择性好,形成稳定化合物.Job’s曲线可知受体分子与阴离子形成1∶2的配合物,并利用核磁滴定与理论计算[B3LYP/6-31G(d,p)]进一步证实了受体分子与阴离子的氢键作用.  相似文献   

10.
(1S,3S)-1,3-二苯基-1,3-丙二胺的合成   总被引:1,自引:1,他引:0  
以二氯甲烷作溶剂,N-Boc保护的二氢吡唑在六甲基磷酰胺存在下与苯基格氏试剂反应,比较大量地制备了对应的四氢吡唑(4);再由4合成消旋的1,3-二苯基-1,3-丙二胺(1,总收率35%);1经L-二苯甲酰酒石酸盐拆分制得光学纯的(1S,3S)-1,3-二苯基-1,3-丙二胺,其结构经1HNMR确证。  相似文献   

11.
New hybrid ligands are reported that combine two types of popular donor groups within a single linear scaffold, viz., a central pyrazolate bridge and two appended bis(N‐heterocyclic carbene) units; the ligand strands thus provide two potentially tridentate {NCC} compartments. The pyrazole/tetraimidazolium proligands, [H5L1](PF6)4 and [H5L2](PF6)4 , were synthesized via multi‐step protocols, and the NH prototropy of [H5L1](PF6)4 was examined by variable temperature (VT) NMR spectroscopy, giving solvent dependent activation parameters (ΔH? = 27.6 kJ · mol–1, ΔS? = –125 J · mol–1 · K–1 in [D3]MeCN; ΔH? = 40.4 kJ · mol–1, ΔS? = –86.9 J · mol–1 · K–1 in [D6]DMSO) that are in the range typical for pyrazoles. Reaction of the proligands with Ag2O gave hexametallic complexes [Ag6(L1)2](PF6)4 and [Ag6(L2)2](PF6)4 that involve all six potential donor atoms of the ligands, viz. the four CNHC and two Npz donors, in metal coordination. X‐ray crystallography revealed a chair‐like central {Ag6} deck in both complexes but different arrangements of the ligand strands, which goes along with significantly different AgI ··· AgI distances that indicate more pronounced argentophilic interactions in case of [Ag6(L1)2]4 +.  相似文献   

12.
The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the intriguing diversity of their architectures and topologies. However, building MOFs with different topological structures from the same ligand is still a challenge. Using 3‐nitro‐4‐(pyridin‐4‐yl)benzoic acid (HL) as a new ligand, three novel MOFs, namely poly[[(N,N‐dimethylformamide‐κO)bis[μ2‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ3O,O′:N]cadmium(II)] N,N‐dimethylformamide monosolvate methanol monosolvate], {[Cd(C12H7N2O4)2(C3H7NO)]·C3H7NO·CH3OH}n, ( 1 ), poly[[(μ2‐acetato‐κ2O:O′)[μ3‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ3O:O′:N]bis[μ3‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ4O,O′:O′:N]dicadmium(II)] N,N‐dimethylacetamide disolvate monohydrate], {[Cd2(C12H7N2O4)3(CH3CO2)]·2C4H9NO·H2O}n, ( 2 ), and catena‐poly[[[diaquanickel(II)]‐bis[μ2‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ2O:N]] N,N‐dimethylacetamide disolvate], {[Ni(C12H7N2O4)2(H2O)2]·2C4H9NO}n, ( 3 ), have been prepared. Single‐crystal structure analysis shows that the CdII atom in MOF ( 1 ) has a distorted pentagonal bipyramidal [CdN2O5] coordination geometry. The [CdN2O5] units as 4‐connected nodes are interconnected by L? ligands to form a fourfold interpenetrating three‐dimensional (3D) framework with a dia topology. In MOF ( 2 ), there are two crystallographically different CdII ions showing a distorted pentagonal bipyramidal [CdNO6] and a distorted octahedral [CdN2O4] coordination geometry, respectively. Two CdII ions are connected by three carboxylate groups to form a binuclear [Cd2(COO)3] cluster. Each binuclear cluster as a 6‐connected node is further linked by acetate groups and L? ligands to produce a non‐interpenetrating 3D framework with a pcu topology. MOF ( 3 ) contains two crystallographically distinct NiII ions on special positions. Each NiII ion adopts an elongated octahedral [NiN2O4] geometry. Each NiII ion as a 4‐connected node is linked by L? ligands to generate a two‐dimensional network with an sql topology, which is further stabilized by two types of intermolecular OW—HW…O hydrogen bonds to form a 3D supramolecular framework. MOFs ( 1 )–( 3 ) were also characterized by powder X‐ray diffraction, IR spectroscopy and thermogravimetic analysis. Furthermore, the solid‐state photoluminescence of HL and MOFs ( 1 ) and ( 2 ) have been investigated. The photoluminescence of MOFs ( 1 ) and ( 2 ) are enhanced and red‐shifted with respect to free HL. The gas adsorption investigation of MOF ( 2 ) indicates a good separation selectivity (71) of CO2/N2 at 273 K (i.e. the amount of CO2 adsorption is 71 times higher than N2 at the same pressure).  相似文献   

13.
The preparation of (2S,3S)‐ and (2R,3S)‐2‐fluoro and of (3S)‐2,2‐difluoro‐3‐amino carboxylic acid derivatives, 1 – 3 , from alanine, valine, leucine, threonine, and β3h‐alanine (Schemes 1 and 2, Table) is described. The stereochemical course of (diethylamino)sulfur trifluoride (DAST) reactions with N,N‐dibenzyl‐2‐amino‐3‐hydroxy and 3‐amino‐2‐hydroxy carboxylic acid esters is discussed (Fig. 1). The fluoro‐β‐amino acid residues have been incorporated into pyrimidinones ( 11 – 13 ; Fig. 2) and into cyclic β‐tri‐ and β‐tetrapeptides 17 – 19 and 21 – 23 (Scheme 3) with rigid skeletons, so that reliable structural data (bond lengths, bond angles, and Karplus parameters) can be obtained. β‐Hexapeptides Boc[(2S)‐β3hXaa(αF)]6OBn and Boc[β3hXaa(α,αF2)]6‐OBn, 24 – 26 , with the side chains of Ala, Val, and Leu, have been synthesized (Scheme 4), and their CD spectra (Fig. 3) are discussed. Most compounds and many intermediates are fully characterized by IR‐ and 1H‐, 13C‐ and 19F‐NMR spectroscopy, by MS spectrometry, and by elemental analyses, [α]D and melting‐point values.  相似文献   

14.
Two novel tridentate ligands of 2,6‐bis‐[l‐(2,6‐dibromophenylimino) ethyl] pyridine (L1) and2‐acetyl‐6‐[1‐(2,6‐dibromophenylimino) ethyl] pyridine (L2) have been synthesized. The iron(II) complex of L1 and L2 has been characterized with the crystal structure of [Fe(L1)(L2)]2+ [FeCl4]2 CH2Cl2 [monoclinic, P21 (#11), a = 1.0562(4), b = 2.0928(4), c = 1.2914(2) nm, β = 100.12°, V = 2.810(1) nm3 Dc = 1.879 g/cm3 and Z = 2].  相似文献   

15.
N‐Boc/Fmoc/Z‐N′‐formyl‐gem‐diaminoalkyl derivatives, intermediates particularly useful in the synthesis of partially modified retro‐inverso peptides, have been characterized by both positive and negative ion electrospray ionization (ESI) ion‐trap multi‐stage mass spectrometry (MSn). The MS2 collision induced dissociation (CID) spectra of the sodium adduct of the formamides derived from the corresponding N‐Fmoc/Z‐amino acids, dipeptide and tripeptide acids show the [M + Na‐NH2CHO]+ ion, arising from the loss of formamide, as the base peak. Differently, the MS2 CID spectra of [M + Na]+ ion of all the N‐Boc derivatives yield the abundant [M + Na‐C4H8]+ and [M + Na‐Boc + H]+ ions because of the loss of isobutylene and CO2 from the Boc protecting function. Useful information on the type of amino acids and their sequence in the N‐protected dipeptidyl and tripeptidyl‐N′‐formamides is provided by MS2 and subsequent MSn experiments on the respective precursor ions. The negative ion ESI mass spectra of these oligomers show, in addition to [M‐H]?, [M + HCOO]? and [M + Cl]? ions, the presence of in‐source CID fragment ions deriving from the involvement of the N‐protecting group. Furthermore, MSn spectra of [M + Cl]? ion of N‐protected dipeptide and tripeptide derivatives show characteristic fragmentations that are useful for determining the nature of the C‐terminal gem‐diamino residue. The present paper represents an initial attempt to study the ESI‐MS behavior of these important intermediates and lays the groundwork for structural‐based studies on more complex partially modified retro‐inverso peptides. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

16.
In the title coordination polymer, catena‐poly[[dichloridomanganese(II)]‐μ‐1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azaniumylylidene)]dibut‐1‐en‐1‐olate‐κ2O:O′], [MnCl2(C26H30N2)]n, synthesized by the reaction of the chiral Schiff base ligand 1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azanediyl)]dibut‐2‐en‐1‐one (L) with MnCl2·4H2O, the asymmetric unit contains one crystallographically unique MnII ion, one unique spacer ligand, L, and two chloride ions. Each MnII ion is four‐coordinated in a distorted tetrahedral coordination environment by two O atoms from two L ligands and by two chloride ligands. The MnII ions are bridged by L ligands to form a one‐dimensional chain structure along the a axis. The chloride ligands are monodentate (terminal). The ligand is in the zwitterionic enol form and displays intramolecular ionic N+—H...O hydrogen bonding and π–π interactions between pairs of phenyl rings which strengthen the chains.  相似文献   

17.
Reaction of 7‐{(N‐2,6‐R)iminomethyl)}indole ( HL1 , R = dimethylphenyl; HL2 , R = diisopropylphenyl) and rare‐earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, generated new rare‐earth metal bis(alkyl) complexes LLn(CH2SiMe3)2(THF) [L = L1: Ln = Lu ( 1a ), Sc ( 1b ); L = L2: Ln = Lu ( 3a ), Sc ( 3b )] and mono(alkyl) complexes L22Lu(CH2SiMe3) ( 4a ). Treatment of alkyl complexes 1a and 4a with N,N′‐diisopropylcarbodiimide afforded the corresponding amidinates L1Lu{iPr2NC(CH2SiMe3)NiPr2}2 ( 2a ) and L22Lu{iPr2NC(CH2SiMe3)NiPr2} ( 5a ), respectively. These new rare‐earth metal alkyls and amidinates except 4a in combination with aluminum alkyls and borate generated efficient homogeneous catalysts for the polymerization of isoprene, providing high cis‐1,4 selectivity and high molar mass polyisoprene with narrow molar mass distribution (Mn = 2.65 × 105, Mw/Mn = 1.07, cis‐1,4 98.2%, −60 °C). The environmental hindrance around central metals arising from the bulkiness of the ligands, the Lewis‐acidity of rare‐earth metal ions, the types of aluminum tris(alkyl)s and borate, and polymerization temperature influenced significantly on both the catalytic activity and the regioselectivity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5251–5262, 2008  相似文献   

18.
Using polynuclear metal clusters as nodes, many high‐symmetry high‐connectivity nets, like 8‐connnected bcu and 12‐connected fcu , have been attained in metal–organic frameworks (MOFs). However, construction of low‐symmetry high‐connected MOFs with a novel topology still remains a big challenge. For example, a uninodal 8‐connected lsz network, observed in inorganic ZrSiO4, has not been topologically identified in MOFs. Using 2,2′‐difluorobiphenyl‐4,4′‐dicarboxylic acid (H2L) as a new linker and 1,2,4‐triazole (Htrz) as a coligand, a novel three‐dimensional CdII–MOF, namely poly[tetrakis(μ4‐2,2′‐difluorobiphenyl‐4,4′‐dicarboxylato‐κ5O1,O1′:O1′:O4:O4′)tetrakis(N,N‐dimethylformamide‐κO)tetrakis(μ3‐1,2,4‐triazolato‐κ3N1:N2:N4)hexacadmium(II)], [Cd6(C14H6F2O4)4(C2H2N3)4(C3H7NO)4]n, (I), has been prepared. Single‐crystal structure analysis indicates that six different CdII ions co‐exist in (I) and each CdII ion displays a distorted [CdO4N2] octahedral geometry with four equatorial O atoms and two axial N atoms. Three CdII ions are connected by four carboxylate groups and four trz ligands to form a linear trinuclear [Cd3(COO)4(trz)4] cluster, as do the other three CdII ions. Two Cd3 clusters are linked by trz ligands in a μ1,2,4‐bridging mode to produce a two‐dimensional CdII–triazolate layer with (6,3) topology in the ab plane. These two‐dimensional layers are further pillared by the L2− ligands along the c axis to generate a complicated three‐dimensional framework. Topologically, regarding the Cd3 cluster as an 8‐connected node, the whole architecture of (I) is a uninodal 8‐connected lsz framework with the Schläfli symbol (422·66). Complex (I) was further characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction, thermogravimetric analysis and a photoluminescence study. MOF (I) has a high thermal and water stability.  相似文献   

19.
In the course of the first of several attempts to elaborate methods for the synthesis of 1‐nitropiperidinoses, lincosamine was transformed into lactam 6 via hemiacetal 1 , lactone 2 , amide 3 , oxo amide 4 , and its cyclic tautomer 5 . Treatment of the N‐Boc‐protected lactam oxime 9 , obtained from lactam 6 , with brominating agents failed to provide the bromonitroso carbamate 10 . The N‐Boc‐protected lactam 13 derived from 6 was reduced to hemiacetal 14 , but the corresponding N‐Boc‐aminooxime did not tautomerise to the C(1)‐hydroxylamine, and nitrone 17 , a potential precursor of the nitropiperidine 12 , was not formed. Oxidation of the anomeric azide 20 with HOF?MeCN failed to provide the expected nitropiperidine 21 . The phosphinimines 22 derived from 20 did not react with O3. In the next approach to 1‐nitropiperidinoses, we treated the N‐Boc‐protected hemiacetal 25 , obtained from the known gluconolactam 23 with N‐benzylhydroxylamine. The resulting nitrone 26 exits in equilibrium with the anomeric N‐benzyl‐glycosylhydroxylamine that was oxidized to the anomeric nitrone 28 . Ozonolysis of 28 led to the hemiacetal 25 , resulting from the desired, highly reactive protected nitropiperidinose 29 , that was evidenced by an IR band at 1561 cm?1. Similarly to the synthesis of nitrone 26 , reaction of the N‐tosyl‐protected hemiacetal 31 with N‐benzylhydroxylamine and oxidation provided the anomeric N‐benzylhydroxylamines 33 via the p‐toluenesulfonamido nitrone 32 . Their oxidation with MnO2 led to the anomeric nitrone 34 . Ozonolysis of 34 as evidenced by 1H‐NMR and ReactIR spectroscopy led to the highly reactive nitropiperidinose 35 . Like 29, 35 was transformed during workup, and only the hemiacetal 31 was isolated. The similarly prepared lincosamine‐derived nitrone 17 was subjected to ReactIR‐monitored ozonolysis that evidenced the formation of the protected nitropiperidinose 12 , but only led to the isolation of 14 . The facile transformation of the nitropiperidinoses to hemiacetals is rationalised by heterolysis of the anomeric C,N bond, recombination of the ion pair, and denitrosation of the resulting anomeric nitrite by a nucleophile. Attempts to convert the 1‐deoxy‐1‐nitropiperidinose 35 to uloses 43 by base‐catalysed Michael additions or Henry reactions were unsuccessful.  相似文献   

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