两种新型F-荧光化学传感器的合成及其性质研究

本文设计合成了N⁶-对甲苯磺酰胺腺嘌呤(I)和邻苯二对甲苯磺酰胺(Ⅱ)两种主体化合物.通过对其与阴离子物种之间相互作用的研究发现,它们在乙腈溶液中和Cl^-、Br^-、NO₃^-、NO₂^-、HSO₄^-、Ac^-、F^-几种阴离子相互作用时,仅对F^-具有专一的选择性识别作用.F^-离子可使I和Ⅱ主体的荧光吸收猝灭并发生红移.通过试验证明,F^-离子和I、Ⅱ主体的识别作用机理是因形成了激基缔合物.     

氧化蒽基二吲哚基甲烷显色现象的研究

通过两步反应合成了两个具有显色特性的化合物:氧化2-蒽基二吲哚基甲烷(2-AnBIM)和氧化9-蒽基二吲哚基甲烷(9-AnBIM).比较了它们在不同非质子溶剂、不同阴离子和酸性环境中的光谱行为.在非质子溶剂中,发现这两种化合物仅在CCl₄中有很大的红移,该红移现象的本质尚不清楚.浓度效应与NMR证据均表明在CCl₄中化合物存在基于氢键的分子间相互作用.在含有不同阴离子的乙腈中,2-AnBIM对F^-离子有选择性响应,而9-AnBIM则对F^-、Cl^-和Ac^-等阴离子均有响应;在质子性溶剂中二者均只对HSO₄^-有选择性响应.2-AnBIM与9-AnBIM在77 K下有荧光发射,而平面性较好的2-AnBIM具有较低的发射能级与较强的发光效率.室温下二者均无明显的荧光发射,这可能与激发态下快速的质子转移导致分子共轭、共平面程度降低有关.     

基于蒽酰亚胺基团的新型Fe3+和Hg2+化学敏感器

含蒽酰亚胺基团的化合物N-(2-(6-氨基吡啶))-9-蒽酰亚胺(L¹)对Fe³⁺表现出灵敏的荧光增强响应.L¹的衍生物N,N-’(2,6-吡啶基)-二(9-蒽酰亚胺)(L²)对Hg²⁺在紫外-可见吸收光谱和荧光光谱上显示了良好的识别性.即使在其它金属阳离子存在下,L¹和L²分别对于Fe³⁺和Hg²⁺仍然表现出较好的选择性.     

基于1,8-萘酰亚胺与罗丹明B间荧光共振能量转移的高选择性Hg2+比率荧光探针

以罗丹明B与1,8-萘二甲酰亚胺反应合成了1个高选择性Hg²⁺比率荧光探针(RN). 在甲醇/乙腈/4-羟基哌嗪乙磺酸缓冲溶液(pH=7.2, 体积比8:1:1)中, RN对Hg²⁺具有比色和比率荧光双重响应. 加入Hg²⁺后, RN的紫外-可见光谱在约556 nm处产生强吸收, 溶液由浅绿色变为橙色, 其它金属离子对RN的紫外-可见光谱几乎无影响. 无Hg²⁺存在时, RN的荧光光谱在540 nm处出现萘二甲酰亚胺荧光团的特征峰; 加入Hg²⁺后, 540 nm处的发射带逐渐消失, 同时在580 nm附近产生强荧光, 荧光颜色从绿色变为橙色. 这归因于从萘酰亚胺到开环罗丹明B的荧光共振能量转移(FRET), 探针RN对Hg²⁺的比率荧光响应具有高选择性, 不受其它共存金属离子的干扰.     

一类以光度法进行检测的新型阴离子敏感化合物

对6种带羟基的分子内电荷转移化合物(其中化合物1,4,5,6含氰基基团)及与不同阴离子间的相互作用及其分子识别进行了研究.发现化合物2,3,5,6均对F^-离子有优良的检测能力,并对H₂PO₄^-有一定的响应能力,其中化合物2对AcO^-离子也有一定的响应.对实验结果进行了初步讨论,并对提高敏感化合物的灵敏度和选择性提出了看法.     

含脲苯并咪唑类离子液体的合成及阴离子识别性能

设计并合成了含脲苯并咪唑离子液体受体分子1~3, 利用紫外-可见光谱、 荧光光谱和 ¹H NMR滴定研究了其对F^-, Cl^-, Br^-, I^-, CH₃COO^-, HSO₄^-, H₂PO₄^-等阴离子的识别性能. 紫外-可见光谱研究发现, 受体分子1~3可选择性地识别F^-, 并形成1: 1型主客体配合物; 荧光光谱研究发现, 受体分子1~3对碱性阴离子有较好的识别作用, 主客体结合常数的顺序为H₂PO₄^->CH₃COO^-≈ F^->HSO₄^- ≈ Cl^->Br^- ≈ I^-; ¹H NMR滴定研究发现, 该类受体分子以咪唑2位CH和脲基NH与阴离子通过氢键结合, 但高浓度的F^-会导致受体分子发生脱质子作用.     

香豆素衍生物对阴离子的识别特性

用紫外光谱滴定法研究了3种香豆素衍生物与阴离子间存在的特殊识别行为,比较了受体分子结构对阴离子配合物稳定性的影响,以及阴离子浓度对配合物光谱的影响.实验结果表明:受体分子对F^- 、Cl^-、Br^-、Ac^-、H₂PO₄^-、HSO₄^-等不同种阴离子客体的识别能力存在一定差异,受体分子与阴离子通过氢键结合,由于氢键良好的方向性和选择性,对F^-、Ac^-、H₂PO₄^-等有较好的选择性和识别能力,而与其他的阴离子几乎没有作用.     

一种长链烷氧基苯腙衍生物对氟离子的高选择性识别

设计并合成了一种新型长链烷氧基酰腙衍生物1-(2,4-二硝基苯基)-2-(4-(十四烷氧基)亚苄基)肼R,系统研究了受体R对9种阴离子(F^-、Cl^-、Br^-、I^-、HSO^-₄、NO^-₃、ClO^-₄、H₂PO^-₄、Ac^-)的紫外-可见吸收光谱(UV-Vis)及裸眼识别性能。 结果表明,该受体在二甲基亚砜(DMSO)体系中对F^-、Ac^-和H₂PO^-₄表现出良好的UV-Vis及裸眼识别能力。 此外,在H₂O/DMSO(体积比1∶9)体系中可对F^-实现单一UV-Vis及裸眼识别,且检出限可达7.02×10^-7 mol/L,同时制备了受体R对阴离子的检测试纸,Job曲线表明受体与阴离子形成1∶1型配合物。 F^-离子的识别机理为“氢键型”响应识别现象。     

2-羟基-1-萘醛缩2-氨基-4-硝基苯酚亚胺的合成及其阴离子识别性能

以2-羟基-1-萘醛和2-氨基-4-硝基苯酚为原料,通过缩合反应合成了阴离子识别受体2-羟基-1-萘醛缩2-氨基-4-硝基苯酚亚胺（R）,其结构经¹H NMR, ¹³C NMR和IR表征。采用UV-Vis和¹H NMR等研究了受体R对阴离子的识别性能。结果表明：受体R在乙腈中对F^-、 H₂PO₄^-和AcO^-表现出良好的UV0Vis识别能力,且对上述阴离子表现出裸眼识别性能。通过核磁滴定、紫外滴定、络合常数及Job曲线等对受体R的识别机理进行了研究。结果表明：受体R与阴离子通过分子间氢键结合形成主客体配合物,对F^-具有更好的结合能力（络合常数为2.503 × 10⁴ L/mol）,与阴离子以比例1/1相互结合。     

三足苯甲酰基硫脲类离子受体的合成及识别性能

本文设计并合成了两种新型含酰基硫脲结构单元的三足受体1和2,并对其结构进行了表征确证。研究表明该类受体化合物对F^-、Ac^-和CN^-表现出良好的紫外识别能力,由于受体1分子内电荷转移作用较强,故对阴离子表现出裸眼识别性能。紫外滴定表明,该类化合物对F^-和CN^-具有更好的结合能力;核磁滴定表明,阴离子通过分子间氢键与受体化合物结合形成主客体配合物,在高浓度F^-时受体化合物发生脱质子行为。此外,该类化合物对Hg²⁺具有一定的荧光选择性识别能力。     

Synthesis and characterization of 3,5-bis(2-hydroxyphenyl)-1,2,4-triazole functionalized tetraaryloxy perylene bisimide and metal-directed self-assembly

[structure: see text] New perylene bisimide dyes bearing 3,5-bis(2-hydroxyphenyl)-1,2,4-triazole receptor units with different spacers have been synthesized and characterized. The fluorescence and electronic properties of these compounds have been studied. MALDI-TOF, UV-vis, and fluorescence titration experiments proved that monotopic perylene bisimide ligands could be assembled into dimmers by Fe(III) coordination. The coordination properties of the ditopic perylene bisimide ligands have also been studied preliminarily. Furthermore, the SEM images indicated that well-defined nanoscale structures could be fabricated by self-assembly due to metal ion coordination and pi-pi stacking interactions of perylene rings with the help of a proper spacer.     

Self-assembly and characterization of hydrogen-bond-induced nanostructure aggregation.

A supramolecular system of a perylene derivative containing bis(2,6-diacylaminopyridine) units and a perylene bisimide bound through three hydrogen-bonds was synthesized and characterized. 1H NMR spectra confirmed the existence of hydrogen-bonding interactions between the perylene derivative (3) and the perylene bisimide (7). The photocurrent generation of the self-assembled 3.7 film was measured, and a cathodic photocurrent response was obtained. SEM images indicated that well-defined long fibers could be fabricated by self-assembly, by exploiting the hydrogen bonding interactions and pi-pi stacking interactions of perylene rings.     

Supramolecular nanoribbons and nanoropes generated from hydrogen-bonded supramolecular polymers containing perylene bisimide chromophores

A perylene bisimide anchored with melamine hydrogen-bonding units has been prepared, and its supramolecular polymerization upon binding with N-dodecylcyanurate (CA) was examined. The resulting flexible supramolecular polymers self-organized via a pi-pi stacking interaction between perylene chromophores, affording ribbonlike aggregates in cyclic alkanes and ropelike aggregates in acyclic alkanes to form gels. [structure: see text]     

Facilitated transport from ternary cation mixtures through water—chloroform—water membrane systems containing macrocyclic ligands

Cation fluxes were determined for various three-component, equimolar mixtures of alkali metal, alkaline earth, and Pb²⁺ cations in a H₂O---CHCl₃---H₂O liquid membrane system incorporating macrocyclic polyethers as carriers. Carrier ligands studied were 18-crown-6, dicyclohexano-18-crown-6, 1,10-diaza-18-crown-6, 21-crown-7, dibenzo-24-crown-8, and cryptand [2.2.2]. Correlations were found between transport and relative cation:polyether cavity radii, the type of substituents present on the polyether ring, and the type and number of donor atoms present. All the ligands studied transported Pb²⁺ at higher rates than the other Mⁿ⁺ in the mixtures. Transport behavior in these multi-cation systems can be predicted from Mⁿ⁺—polyether complex stability constant data in most cases.     

Chiral self-assembly of lactose functionalized perylene bisimides as multivalent glycoclusters

A chiral self-assembly has been constructed from a d-lactose functionalized perylene bisimide derivative, showing right-handed supramolecular stacking induced by the chiral d-lactose moieties. Benefiting from the grafting of D-lactose, the self-assembled multivalent glycoclusters exhibited specific binding with PNA lectin.     

Fluorescent and electroactive cyclic assemblies from perylene tetracarboxylic acid bisimide ligands and metal phosphane triflates

Tetraaryloxy-substituted perylene tetracarboxylic acid bisimides with one or two 4-pyridyl receptor substituents at the imide functionality were synthesized and employed in transition metal directed self-assembly with Pd(II) and Pt(II) phosphane triflates. Upon mixing of the components, quantitative formation of functional molecular square-type complexes containing four dye molecules and model complexes of a 2:1 (perylene bisimide ligand:transition metal ion) stoichiometry was observed. The isolated metallosupramolecular squares were characterized by 1H and 31P [1H] NMR spectroscopy as well as conventional electrospray ionization (ESI) and ESI-FTICR mass spectrometry, which gave evidence for the structure and the high stability of these giant cyclic dye assemblies (molecular weight (3a) 8172, Pt-Pt corner diagonal ca. 3.4 nm). Studies of the optical absorption and fluorescence properties and the electrochemistry and spectroelectrochemistry of both the perylene bisimide ligands and the perylene bisimide metal complexes show that Pt(II) coordination does not interfere with the optical and electrochemical properties of the perylene bisimide ligands; this gives squares with high fluorescence quantum yields (phiF (3a)=0.88) and three fully reversible redox couples. The latter could be unambiguously related to quantitative formation of perylene bisimide radical cations (E1/2 = +0.93 V vs. Fc/Fc+), radical anions (E1/2= - 1.01 V vs. Fc/Fc+), and dianions (E1/2 = -1.14 V vs. Fc/Fc+); these redox reactions change the charge state of the cyclic assembly from +12 to zero. In contrast, Pd(II) coordination influenced the electrochemical properties of the assembly because of an irreversible palladium reduction at E1/2= -1.15 V versus Fc/Fc+. Finally, dynamic ligand exchange processes between different metallosupramolecular assemblies were investigated by multinuclear NMR and electrospray mass spectrometry. These studies confirmed the reversible nature of the pyridine-Pt(II)/Pd(II) coordination process.     

Azacrown ethers containing oximic and Schiff base sidearms - potential heteronuclear metal ion receptors

A simple synthetic pathway for the preparation of oxime- and Schiff base-containing aza- and diazacrown ethers is reported. N-Methoxymethyl-substituted aza-15-crown-5 and aza-18-crown-6 as well as N,N′-bis(methoxymethyl)-substituted diaza-18-crown-6 were treated with 5-bromosalicylaldehyde to produce the N-(2′-hydroxy-3′-carbonyl-5′-bromobenzyl)-substituted aza-15-crown-5 (8), aza-18-crown-6 (9) and N,N′-bis(2′-hydroxy-3′-carbonyl-5′-bromobenzyl)-substituted diaza-18-crown-6 (10) compounds. Compounds 8 and 10 were treated with hydroxylamine to give oxime-substituted ligands 12 and 13. A series of bis-Schiff base-containing diaza-18-crown-6 ligands were prepared by reacting 10 with 2-hydroxyaniline (to form 14), 5-nitro-2-hydroxyaniline (15), 2-aminopyridine (16), 2-hydrazinopyridine (17) and N-aminomorpholine (18). Compounds 12–18 are potential complexing agents for simultaneous binding of soft transition and hard alkali or alkaline earth metal ions in one molecule. These new oxime- and Schiff base-containing ligands interacted strongly with Na⁺ and K⁺ in methanol. The interaction of the aromatic portions of 9, 10, and 12–15 with transition metal ions was shown by the UV spectra of the metal ion complexes in 50% aqueous DMF. The X-ray structure of 10 is reported.     

Light-harvesting metallosupramolecular squares composed of perylene bisimide walls and fluorescent antenna dyes

The fluorescent dye 4-dimethylamino-1,8-naphthalimide was incorporated at the bay area of N,N'-bispyridyl perylene bisimide to afford a fourfold-functionalized perylene bisimide ligand. Through self-assembly directed by metal-ion coordination, a multichromophore supramolecular entity composed of sixteen dimethylaminonaphthalimide antennas and a perylene bisimide-walled square core was subsequently constructed from this linear ditopic ligand and 90 degrees metal corner [Pd(dppp)](OTf)2 (dppp=1,3-bis(diphenylphosphino)propane; OTf=trifluoromethanesulfonate) in good yield. The isolated metallosupramolecular square was characterized by elemental analysis and 1H, 13C, and 31P{1H} NMR and UV/Vis spectroscopy. Furthermore, by means of 1H NMR diffusion-ordered spectroscopy (DOSY) the dimension of this assembly was evaluated by employing a previously reported perylene bisimide ligand and its square assembly as references. The results obtained confirm the square framework of the current assembly. The optical properties of this multichromophore dye assembly were investigated by UV/Vis and steady-state and time-resolved fluorescence spectroscopy. It was revealed that light captured by dimethylaminonaphthalimide antennas could be efficiently transported to the perylene bisimide core by a fluorescence resonance mechanism (energy-transfer efficiency E=95%), and this resulted in almost exclusive detection of intense perylene bisimide emission, irrespective of the excitation wavelength applied. The present square scaffold containing aminonaphthalimide antenna dyes exhibits more than seven times higher fluorescence quantum yield (Phifl=0.37) than a previously reported pyrene-bearing perylene bisimide-walled square (Phifl=0.05). Thus, this multichromophore square assembly with aminonaphthalimide antenna dyes is an artificial model for the cyclic light-harvesting complexes in purple bacteria.     

Controllable Self‐Assembly of Amphiphilic Zwitterionic PBI Towards Tunable Surface Wettability of the Nanostructures

Amphiphilic molecules have received wide attention as they possess both hydrophobic and hydrophilic properties, and can form diverse nanostructures in selective solvents. Herein, we report an asymmetric amphiphilic zwitterionic perylene bisimide ( AZP ) with an octyl chain and a zwitterionic group on the opposite imide positions of perylene tetracarboxylic dianhydride. The controllable nanostructures of AZP with tunable hydrophilic/hydrophobic surface have been investigated through solvent‐dependent amphiphilic self‐assembly as confirmed by SEM, TEM, and contact angle measurements. The planar perylene core of AZP contributes to strong π–π stacking, while the amphiphilic balance of asymmetric AZP adjusts the self‐assembly property. Additionally, due to intermolecular π–π stacking and solvent–solute interactions, AZP could self‐assemble into hydrophilic microtubes in a polar solvent (acetone) and hydrophobic nanofibers in an apolar solvent (hexane). This facile method provides a new pathway for controlling the surface properties based on an asymmetric amphiphilic zwitterionic perylene bisimide.     

Crystal structure and phase transition of 2-methoxyanilinium perchlorate-18-crown-6

A new phase transition compound,2-methoxyanilinium perchlorate-18-crown-6(1) {(oCH3OC6H4NH3)+(18-crown-6) ClO4 },has been synthesized and separated as crystals.Differential scanning calorimetry(DSC) measurements show a pair of sharp peaks at 225 K(heating) and 210 K(cooling),indicating the phase transition is first-order.Dielectric anomalies observed at 225 K(heating)and 210 K(cooling) further confirm the phase transition.The crystal structures determined at 298 K and123 K are both triclinic in P 1.The most distinct difference between room-temperature and lowtemperature structures is the order–disorder transition of the host 18-crown-6 molecule,which is the driving force of the phase transition.