两种新型吡啶盐的合成，表征及双光子性质研究

本文报道了两种新的吡啶盐的合成，用元素分析、红外光谱、单晶X-射线衍射进行了表征。研究了它们的紫外光谱、荧光光谱和光限幅特性，发现它们的DMF溶液对1 064 nm皮秒脉冲激光表现出明显的光限幅特性。     

一种具有双光子活性的新型吡啶盐的合成、表征及性质

一种具有双光子活性的新型吡啶盐的合成、表征及性质;D-π-A吡啶盐; 三阶非线性光学特性; 单晶X射线衍射; Z扫描     

新型苯并噁唑基吡啶盐的合成及其线性光学性质

以邻氨基苯酚和对甲基苯甲酸为原料,多聚磷酸为溶剂,N₂保护下于220 ℃反应制得中间体L1; L1溴代得中间体L2; L2与三苯基膦反应得膦盐L3,L3与吡啶-3-甲醛通过Wittig反应制得中间体L4,再通过甲基化反应和阴离子置换合成了未见报导的化合物1~6,并利用¹H NMR, ¹³C NMR, FT-IR和HR-MS对化合物1~6的结构进行了表征。单晶结构测试表明:化合物1(CCDC: 1838541)的阳离子部分的平面性较好。紫外可见吸收光谱和荧光发射光谱结果表明：化合物1~6在不同极性溶剂中均具有良好的光学性质。     

新型蓝色上转换荧光分子的合成、表征与双光子吸收性能

设计并合成了3 个新的受体-给体-受体(A-D-A)构型上转换荧光分子,用傅里叶变换红外光谱、核磁共振氢谱、质谱和元素分析进行了表征. 测定了它们在不同溶剂中的线性吸收光谱、单光子荧光光谱和荧光量子产率. 以飞秒激光作为光源,研究了它们的双光子吸收和上转换荧光特性. 结果表明：该类化合物的荧光量子产率为0.20-0.68,双光子吸收截面为16×10^-50-101×10^-50 cm⁴·s·photon^-1,具有较强的蓝色上转换荧光发射.     

新型有机盐光引发剂的双光子聚合特性研究

本文运用激光微细加工技术,通过对不同浓度引发剂的甲基丙烯酸类树脂的聚合行为进行评价,研究了1-甲基-2-[2-(9-戊基-咔唑-3-基)-乙烯基]-3,3-二甲基吲哚碘盐(I)作为双光子光引发剂的聚合特性,结果表明该化合物在扫描速度为44μm/s时,双光子聚合阈值为139kJ/cm²;当激光能量密度为286kJ/cm²时,引发聚合的曝光时间阈值为0.7ms.实验结果为进一步作为双光子聚合三维结构的微细加工提供了可靠依据.     

1,3,4-噁二唑衍生物的双光子吸收和双光子泵浦荧光

依据“推电子基-共轭中心-拉电子基-共轭中心-推电子基”的模型将电荷传输型1,3,4-噁二唑环嵌入芳香共轭体中, 通过Wittig-Horner反应合成了2种对称型强双光子吸收和双光子诱导荧光分子2,5-二[4-(2-芳基乙烯基)苯基]-1,3,4-噁二唑. 它们的氯仿溶液在锁模Nd: YAG激光器800 nm激光照射下, 发射出很强的双光子上转换荧光, 其最强荧光分别在波长507和475 nm. 采用非线性透过率法测得其双光子吸收截面分别为1.07×10^－46和6.6×10^－47 cm⁴•s•photon^－1. 这2个对称型D-π-A-π-D生色分子从激发端基到π共轭桥的有效能量传输, 对双光子吸收和双光子荧光发射能力贡献较大.     

Synthesis and Two-photon Absorption Properties of s-Triazine Derivatives

Two new s-triazine derivatives, which belong to linear dipolar type and triangle octupolar type respectively, have been synthesized. The structure of the dipolar compound has been determined by X-ray diffraction. The two-photon absorption cross-section σ, and the two-photon excited fluorescence (TPEF) intensities are increased significantly from dipolar compound to octupolar compound.     

Synthesis of Piperidine Derivatives by Reduction of Pyridinium Salts

Piperidine derivatives 1a–e and 2a–f have been prepared by the reduction of 3‐and 4‐substituted pyridinium salts with NaBH₄ in moderate to excellent yields. The reactions regioselectively give 1,2,5,6‐tetrahydropyridines, and the yields depend greatly upon the nature of substituents on the phenyl ring and on the nitrogen atom, the nature and the position of the substituents on the pyridyl ring, and the chain length between the aryloxy and the pyridyl groups.     

Two-Photon Initiating Efficiency of a Ditopic Alkoxynitrostilbene Reacting through a Self-Regenerative Mechanism

The photophysical properties and the photoinitiating reactivity of a ditopic alkoxynitrostilbene were compared to those of its single branch chromophore used as a reference. Whereas a trivial additive effect is observed when considering the one- and two-photon absorption properties, a clear and very significant amplification has been highlighted for the photoreactivity of this free radical photoinitiator which was used as a hydrogen abstractor in presence of an aliphatic amine co-reactant. We indeed demonstrate that the proximity of two nitroaromatics moieties within the same molecular architecture gives rise to an original cycling mechanism based on a stepwise photo triggering of each photoredox center followed by a subsequent regenerative process. The combination of a high two-photon absorption cross-section (δ_780nm≈330 GM) with a strong enhancement in photoreactivity makes this nitrostilbene bichromophore a very suitable candidate for two-photon polymerization applications.     

一种新型吡啶鎓盐的合成、结构及光学性质

通过吡啶盐与3，4-二甲氧基苯甲醛在甲醇中反应，得到了一种新型的化合物，即4-[（3"，4"-二甲氧基)苯乙烯基]-N-甲基吡啶高氯酸盐，分子式为C16H18ClNO6。化合物的结构通过红外、元素分析、氢谱、电喷雾质谱和X-单晶衍射仪进行分析与表征。结果表明：该化合物属正交晶系，空间群Pbca，晶胞参数a = 13.5897(11) nm, b = 13.9126(11) nm, c = 17.3485(14) nm, α = 90 °, β = 90 °, γ = 90 °, Mr = 355.76, V = 3280.0(5) nm3, Z = 8, F(000) = 1488, Dc = 1.181 g/cm3, μ = 0.265 mm?1。而且还研究了该化合物的光学性质。     

苯并噻唑衍物的合成及结构-双光子吸收光物理特性关系

报道了三个具有典型A-π-A'型共轭结构的苯并噻唑衍生物的合成及结构-双光 子吸收光物理特性关系。通过对三个化合物的共轭结构增长和拉电子基强度变化对 化合物单光子荧光光谱、双光子诱导荧光光谱和双光子吸收截面等特性的影响研究 ，我们发现，苯并噻唑杂环中的杂原子硫在化合物共轭链链短时对其光物理特性影 响很强，在共轭链较长时影响减弱甚至消失。通常情况下，共轭链长度和拉电子基 强度共同对双光子吸收截面作贡献，我们的研究表明，当共轭链较长时，共轭链的 增长对增强分子双光子吸收截面的贡献远大于拉电子基强度变化的贡献。其中，新 化合物2（2-{4-[2-（4-硝基苯基）-乙烯基]苯基}-乙烯基）苯并噻唑具有双光子 吸收截面大(181*10~(-50)cm~4s/photon)和荧光量子产率高(13.8%)的特点，是双 光子荧光显微与成像应用的一个良好的候选材料。     

具有双光子吸收的咔唑类分子的设计、合成及光谱特性

设计、合成了四个新的咔唑类具有较大双光子吸收截面的化合物,研究它们的光谱特性,对双光子吸收的构效关系进行初步探索.     

Nucleophilic Functionalization of 2-Alkylidene-4-Oxothiazolidines at C(5)-Position Induced by Formation of Novel Pyridinium Salt

Abstract

The synthesis of unsubstituted pyridinium salt containing the 4-oxothiazolidine moiety bondedviaC(5) to the N position of the pyridine nucleus is reported. The nucleophilic displacement of pyridine from pyridinium salt by the selected nucleophiles leads to the formation of new 5-substituted 4-oxothiazolidines in good yields.     

吡啶基团的对称性和离子化对分子双光子吸收截面的影响

采用超快速激光光谱方法研究了含吡啶基团的四个联苯乙烯衍生物及两个杂环分子(A: 4,4’-二(2-(4-吡啶基)乙烯)联苯; B: 4,4’-二(2-(2-吡啶基)乙烯)联苯; C: 1-甲基-4-(2-(4’-(2-(4-吡啶基)乙烯基)-4-联苯)乙烯基)吡啶碘盐; D: 1-甲基-2-(2-(4’-(2-(2-吡啶基)乙烯基)-4-联苯)乙烯基)吡啶碘盐; E: 4-(2-(9-丁基-9氢-3-咔唑)乙烯基)-1-甲基吡啶碘盐; F: 4-(2-(9-丁基-9氢-3-咔唑)乙烯基)-1-甲基喹啉碘盐)的结构-性能关系. 实验结果显示双光子吸收截面最大的是分子E, 高达617.3 GM; 最小的是分子B, 为19.3 GM(1 GM=10^-50 cm⁴·s·photon^-1). 实验研究结果表明, 分子中吡啶基团的对称性及其离子化对分子双光子吸收截面起很重要的作用; 进一步用理论计算证实了以上实验结论并对其机制进行了分析讨论.     

Visible-Light-Induced C4-Selective Functionalization of Pyridinium Salts with Cyclopropanols

The site-selective C?H functionalization of heteroarenes is of considerable importance for streamlining the rapid modification of bioactive molecules. Herein, we report a general strategy for visible-light-induced β-carbonyl alkylation at the C4 position of pyridines with high site selectivity using various cyclopropanols and N-amidopyridinium salts. In this process, hydrogen-atom transfer between the generated sulfonamidyl radicals and O?H bonds of cyclopropanols generates β-carbonyl radicals, providing efficient access to synthetically valuable β-pyridylated (aryl)ketones, aldehydes, and esters with broad functional-group tolerance. In addition, the mild method serves as an effective tool for the site-selective late-stage functionalization of complex and medicinally relevant molecules.     

双光子荧光探针研究及其应用

双光子荧光显微成像兼具诸如近红外激发、暗场成像、避免荧光漂白和光致毒、定靶激发、高横向分辨率与纵向分辨率、降低生物组织吸光系数及降低组织自发荧光干扰等特点而显著地优于单光子荧光显微成像,为生命科学研究提供了更为锐利的工具。而用于像离子的含量及其对生理的影响、离子参与的生理活动机制、离子与分子的作用、特定分子的分布及其相互作用等方面研究的双光子荧光探针,是实现成像的关键。双光子荧光探针的研究旨在促进双光子荧光显微镜应用的发展,促进生命科学、医学科学的快速发展,同时也带动双光子荧光探针所隶属的化学这一学科的发展。因此对双光子荧光探针的研究具有重要的理论和实践意义。该文综述了双光子荧光显微成像的优点、双光子荧光探针设计的原理及双光子荧光探针在离子分析方面的应用,并展望了这类荧光探针的发展趋势与应用前景。     

一个新的具有大的吸收截面的双光子引发剂的合成和非线性光学性质

E,E-1,4-Bis（4＇-N,N-diphenylaminostyryl）-2,5-dimethoxybenzene （DPAMOB） has been synthesized by a simple and effective solid phase Wittig reaction and characterized by 1^H NMR spectra and elemental analysis, Linear absorption, single-photon induced fluorescence and two-photon induced fluorescence spectra were experimentally studied. The new dye has a large two-photon absorption （TPA） cross-section of σr= 1007,2 GM [1 GM= 1 × 10^-50 cm^4·s/（photon molecule）] at 800 nm measured by the two-photon induced fluorescence method. The experimental results confirm that DPAMOB is a good TPA chromophore and can successfully initiate two-photon photopolymerization of ethoxylated trimethylolpropane triacrylate esters （SR454）. Finally, a microstructure has been fabricated by use of DPAMOB as initiator.     

吡啶季铵盐在有机合成中的应用

由于吡啶环的芳香性、碱性、吡啶氮原子的吸电子效应使得吡啶季铵盐具有丰富的化学反应性质, 可以进行亲核加成、Michael加成、1,3-偶极加成、亲核取代和σ-迁移重排等反应, 在有机合成化学中有广泛的应用.     

Synthesis, Characterization and Properties of Tri-substitute Potassium Salt of Trinitrophloroglucinol

The title complex [K3（TNPG）·（H2O）2]n was synthesized by the reaction of the aqueous solutions of trinitrophlomglucinol （TNPG） with KHCO3. The complex was characterized by elemental analysis and FTIR spectroscopy, and its single crystal structure was determined by X-ray diffraction analysis. The structural analysis demonstrates that two different coordination modes of K cations [K（1） and K（2）] are around TNPG^3- anions in complex [Ka（TNPG）·（H2O）2]n, where the coordination numbers are eight. All K atoms coordinate with O atoms of phenolic hydroxyl group and nitro-group simultaneously. The thermolysis of the [Ka（TNPG） · （H2O）2]n has been investigated by using differential scanning calorimetry （DSC） and thermogravimetry-derivative thermogravimetry （TG-DTG） at a heating rate of 10 ℃/min. The thermal decomposition processes of the title complex were comprised of one endothermic dehydration stage and one exothermic decomposition stage in 270-320℃, and the final decomposition residue contained KNC. Impact and friction sensitivity results of the complex revealed its sensitive nature towards mechanical stimuli. The experiments verified that the complex has some characteristics of explosive.     

Synthesis and Characterization of Dipolar Two-Photon Absorption Chromophores

It is a new interest to explore novel organic two-photon absorption (TPA) chromophores with large TPA cross section for their potential applications in various fields, such as three-dimensional optical data storage, micro- and nano-fabrication, biological imaging and optical limiting, and so on. As far as asymmetrical D-π-A type chromophores were concerned, larger TPA cross section can be obtained with the enhancement of electron-donation/electron-acception ability.[1] Recently, we have synthesized a series of new D-π-A type compounds. In these chromophores, stilbene or phenyl cyclo-bridged hexatriene is served as π-bridge, which terminated with a number of amino groups and dicyanomethylene unit (Scheme 1). All the chromophores can be obtained by the condensation reaction of aldehydes and active methyl or methenyl groups in good yields (72%～81%). The chromophores have been characterized by 1H NMR,IR, UV-vis, PL and EA. All these five chromophores in dilute solutions show strong red fluorescence (Table 1). The studies on the TPA properties are in progress.