Design and Synthesis of Dual Fluorescent Neutral Receptors for Molecular Recognition

分子识别是超分子化学的核心研究内容之一,包括离子客体和中性分子的识别。由于荧光检测的高灵敏度和可实时及远程检测等优越性，在分子识别与传感中的应用得到蓬勃发展，设计合成高灵敏、高选择性的荧光化学传感器近年来备受关注。具有分子内电荷转移和激发态质子转移性质的荧光体，发射大Stokes位移的荧光，可消除基质本底荧光和散射光对化学传感和分子识别的潜在不利影响。为此，本论文拟以具有分子内电荷转移双重荧光的对二甲氨基苯甲酰胺衍生物和分子内质子转移的水杨醛衍生物为荧光信号报告基团，耦合阳离子或阴离子识别位点，设计合成了系列荧光化学传感器。论文共分六章。第一章：从分子识别原理上概述了荧光传感器的研究进展，并提...Molecular recognition is an important subject in supramolecular chemistry. Design and synthesis of fluorescent chemsensor have drawn much interests in supramolecular chemistry in recent years due to its intrinsic distinct advantages in terms of high sensitivity, able to monitor substrate concentration in real-time and real-space and remote sensing. Intramolecular charge transfer (ICT) or intramole...学位：理学博士院系专业：化学化工学院化学系_分析化学学号：B20012500

Dual Fluorescence from Aqueous 1-Naphthylamine Solutions of High pH ——Excited-State Acidic Dissociation of Naphthylamine

Dual fluorescence at ca. 447 nm and 545 nm w as observed from the aqueous 12naph thylam ine (NA ) solutions at pH h igher than 1316. Sim ilar dual fluorescence was also found w ith sodium12naph thylam inoacetate (NAA ) , but not w ith N , N 2disubstituted 12am inonaph thalenes such as sodium 12 naph thylam inodiacetate (NADA ) and 12dimethylam inonaph thalene (DMAN ). No change in absorption spectra of NA and NAA w as observed in th is pH region. It w as p roposed that the dual fluorescence ob2 served w ith NA and NAA w as due to the excited state dissociation of the p rimary and secondary am ines at h igh pH. F rom the dual fluorescence intensity ratio pH titration curve, the pK 3 ’ a s of NA and NAA w ere estimated to be betw een 14 and 15 w h ich aremuch low er than the ground state pK a. The novel app roatch is such a simp le, convenient and frequent analysis technique that it can bew idely used in detecting the sub2stitutional derivatives of am inonaph thalene.教育部优秀年轻教师基金(批准号 :教人司 2 0 0 0 -11);国家自然科学基金(批准号 :29975023)

Thiourea-based Receptors for Anion Recognition and Sensing

[中文文摘]阴离子识别是超分子化学研究的重要内容之一 ,其关键环节是构筑可识别阴离子的结合受体 ,后者以非共价键力如静电作用、疏水作用、氢键等与阴离子结合。本文详细评述了近 5年来硫脲类阴离子识别受体的设计、结构及其阴离子识别作用的研究进展。[英文文摘]　Anion recognition and sensing have been developed into an important research subject in supramolecular chemistry. Noncovalent interactions such as hydrogen bonding , electrostatic interaction , hydrophobic interaction , etc.are the most important binding forces existing in the anion2receptor binding complexes , which forms the basis of designing anion binding receptors. The design , construction and anion recognition and sensing of thiourea2based receptors following mainly multi hydrogen bonding interactions are reviewed. 51 key references were cited to represent the related advances in the past 5 years.国家自然科学基金 (2 0 1 75 0 2 0 );福建省自然科学基金 (D0 2 2 0 0 0 1 )项目

Dual fluorescence from aqueous 1-naphthylamine solutions of high pH - Excited-state acidic dissociation of naphthylamine

Dual fluorescence at ca. 447 nm and 545 nm was observed from the aqueous 1-naphthylamine (NA) solutions at pH higher than 13.6. Similar dual fluorescence was also found with sodium 1-naphthylaminoacetate(NAA), but not with N, N-disubstituted 1-aminonaphthalenes such as sodium 1-naphthylaminodiacetate (NADA) and 1-dimethylaminonaphthalene (DMAN). No change in absorption spectra of NA and NAA was observed in this pH region. It was proposed that the dual fluorescence observed with NA and NAA was due to the excited state dissociation of the primary and secondary amines at high pH. From the dual fluorescence intensity ratio pH titration curve, the pK(a)(.)'s of NA and NAA were estimated to be between 14 and 15 which are much lower than the ground state pK(a). The novel approach is such a simple, convenient and frequent analysis technique that it can be widely used in detecting the substitutional derivatives of aminonaphthalene

Thiourea-based receptors for an on recognition and sensing

Anion recognition and sensing have been developed into an important research subject in supramolecular chemistry. Noncovalent interactions such as hydrogen bonding, electrostatic interaction, hydrophobic interaction, etc. are the most important binding forces existing in the anion-receptor binding complexes, which forms the basis of designing anion binding receptors. The design, construction and anion recognition and sensing of thiourea-based receptors following mainly multi hydrogen bonding interactions are reviewed. 51 key references were cited to represent the related advances in the past 5 years

Intramolecular Charge Transfer and Electron Transfer in N-(1-Naphthyl)aminoacetic Acid in Aqueous Solution

pH titration of the fluorescence of N-(1-naphthyl)aminoacetic acid(NAA) was performed in aqueous solution over pH range of 1 5â 12 5. Despite no shift in the fluorescence maximum wavelength, the titration curve showed an Ω-shaped profile with increasing pH with two inflection points at pH 4 1 and pH 11 5, respectively. These values correspond to the excited-state pK *_a î ±s of carboxylic group and ammonium cation, respectively, which are both higher than those of the corresponding ground-state pK_as of 2.64 and 11.83,of which the former changes more.The substantial weakening of the proton dissociation of carboxy lic group in the excited state should be indicative of the decrease in the inductive +I-effect of the ammonium cationat the B-position due to the excited-state intramolecular charge transfer from naphthalene moiety to ammonium.The latter was also confirmed by the slight increase inthe exited-statepK*a2. The fact that the increase inpK*a1is larger than that in pK*a2 suggests that the effect of the intramolecular charge transfer on the involved moiety be weaker than that on are motemoiety in the samespecies.This could be taken into consideration for designing means of tuning the structures and properties of peptide andp roteinvia photo-excitation.It was identified that the NAAzwitterion(â ¡)was the emissivespecies.The fluorescence quenching at high pH was assumed to be due to the photoinduced intramolecular electron transfer between carboxy late anion and the excited naphthalene moiety.The present caserep resents an example in which both in -tramolecular charge transfer and electron transfer occur to shape the pH titration profile.教育部优秀青年教师基金;留学回国人员基金;德国洪堡基金

A novel fluorescent aminoacid designed for fluorometric detection of Cu (II)

A fluorescent aminoacid was designed for selective and sensitive detection of Cu(II) in aqueous solution. The designing of this Cu(II) fluorescent chemosensing molecule, N-(1-naphthyl)aminoacetic acid (NAA), was based on the binding of Cu(B) to aminoacetic acid and the novel charge transfer photophysics of 1-aminonaphthalenes. The fluorescence of NAA was found quenched by Cu (H) and several other metal ions of similar electronic structure such as Co(II), Ni(II) and Zn(II). The quenching was shown to occur via electron transfer within the metal-NAA complex, which required an optimal combination of high binding affinity and favorable redox properties of the components in the metal-NAA complex and hence afforded selective fluorometric detection of Cu(II). The calibration graph obeyed Stern-Volmer theory and was shown for Cu(II) over the range of 0-2.75 x 10(-4) mol/L. The quenching constant of Cu(II) was measured as 8.0 x 10(3) mol/L that was two orders of magnitude higher than those of Co(II), Ni(II) and Zn(II). The 3SD limit of detection for Cu(II) was 8.00 x 10(-6) mol/L with a coefficient of variation of 1.65%. Linear range for quantitative detection of Cu (II) was 2.67 x 10(-5)-2.75 x 10(-4) mol/L. The method was applied to synthetic sample measurements which gave recoveries of 105%-112%

Intramolecular charge transfer and electron transfer in N-(1-naphthyl) aminoacetic acid in aqueous solution

pH titration of the fluorescence of N-(1-naphthyl)aminoacetic acid(NAA) was performed in aqueous solution over pH range of 1.5-12.5. Despite no shift in the fluorescence maximum wavelength, the titration curve showed an Omega -shaped profile with increasing pH with two inflection points at pH 4.1 and pH 11.5, respectively. These values correspond to the excited-state pK(a)*'s of carboxylic group and ammonium cation, respectively, which are both higher than those of the corresponding ground-state PKa' s of 2.64 and 11.83, of which the former changes more. The substantial weakening of the proton dissociation of carboxylic group in the excited state should be indicative of the decrease in the inductive + I-effect of the ammonium cation at the beta -position due to the excited-state intramolecular charge transfer from naphthalene moiety to ammonium. The latter was also confirmed by the slight increase in the exited-state pK(a2)*. The fact that the increase in pK(s1)* is larger than that in pK(a2)* suggests that the effect of the intramolecular charge transfer on the involved moiety be weaker than that on a remote moiety in the same species. This could be taken into consideration for designing means of tuning the structures and properties of peptide and protein via photo-excitation, It was identified that the NAA zwitterion( Il) was the emissive species. The fluorescence quenching at high pH was assumed to be due to the photo-induced intramolecular electron transfer between carboxylate anion and the excited naphthalene moiety. The present cask represents an example in which both intramolecular charge transfer and electron transfer occur to shape the pH titration profile