海萤荧光素类似物发光反应机理的理论研究

选取海萤类似物6-芳基-2-甲基咪唑[1,2-α]吡嗪-3(7H)酮环的C6位取代物(命名为MIPa~MIPd)进行理论研究. 采用密度泛涵理论B3LYP方法在气相和二甲亚砜(DMSO)及二甘醇二甲醚(DG)两种溶剂中, 对这些类似物在脱去二氧化碳反应过程中所涉及的2个反应路径的反应活化能和产物激发态的荧光寿命进行了计算, 结果表明, 取代吡嗪酮的过氧化四元环在DMSO溶剂中的反应活化能较低, 给电子基团作为取代基时反应更快. 在DMSO溶剂中, 路径Ⅱ的荧光量子效率比路径Ⅰ的高, 但在DG溶剂中, 路径Ⅰ的荧光效率高于路径Ⅱ的荧光效率.     

基于C^N^N三齿配体以及苯乙炔基或苯基的环金属化铂磷光络合物的比较研究（英文）

合成了两个系列的以2-芳基-6-(1H-砒唑-1-基)砒啶[芳基=苯基(L1),2,4-二氟苯基(L2),3,5-二甲基苯(L3),3-甲氧基苯基(L4),2-噻吩基(L5),2-苯并噻吩基(L6)]为环金属化配体,以苯乙炔基或苯基为辅助配体的铂化合物1a~6a和1b~6b.其中2b,3b和5b的结构用X射线晶体衍射方法进行了测定.结果表明,辅助基团苯基与配位平面采取一种扭曲的构型.Pt—C(苯基)键较Pt—C(炔基)键弱.对铂化合物的光物理性质包括吸收和发射光谱进行了研究.苯乙炔基取代的铂化合物1a~6a在室温溶液里发射较强的磷光,而苯基取代的确铂化合物1b~3b仅发射很弱的光.但是,化合物4b~6b发射比较强的光,尽管发光效率还是比相应的4a~6a低.这一现象表明4b~6b和4a~6a的激发态可能定域在三齿环金属化配体上.化合物1a~6a表现的较高发光效率可能是因为较强的和刚性的炔基配体.     

密度泛函理论研究温度和取代基对4-亚芳基亚氨基-1,2,4-三唑-3(2H)-酮气相热分解的影响

采用密度泛函理论(DFT)方法, 在B3LYP/6-31＋＋G(d,p)水平上研究了4-亚芳基亚氨基-1,2,4-三唑-3(2H)-酮及其类似物的气相热分解反应. 从热力学性质、几何结构参数、自然电荷分布、温度效应等角度探讨不同取代基对标题物热分解反应的影响. 结果表明: R (R＝H, CH2CH2CN)取代基对反应影响很小; 而苯环上Y (Y＝MeO, Me, H, Cl和NO2)取代基对活化自由能(ΔG≠)、键长(ΔR≠)、键角(Δα≠)和自然电荷(Δq≠)变化的影响与Hammet常数(σ)呈现线性关系ΔP≠＝ρσ＋C (P＝G, R, α和q, r＞0.95). 给电子基团使得相应的活化自由能降低, 键长变短, 键角变大, 自然电荷增加; 吸电子反之.     

含二氮杂萘砌块化合物的荧光性能构效关系研究及应用

通过文献方法合成了具有较好平面共轭结构和较高电子云密度的5-氨基-2-芳基-3H-色烯[4,3,2-de][1,6]并二氮杂萘-4-腈(4)和5-氨基-2-芳基-3H-喹啉[4,3,2-de][1,6]并二氮杂萘-4-腈(6),研究了稠合环数、荧光助色团数量以及取代基类型对产物发光性能的影响,探索了其结构与发光性能之间的关系.在发光性能构效关系指导下初步探究了化合物4对9种金属离子的识别,并从产物中筛选得到了具有进一步研究价值的、具开发为有机荧光材料潜质的产物.     

硅杂环戊二烯衍生物电子结构与光谱性质的理论研究

采用密度泛函理论(DFT)B3LYP/6-31G*方法, 对2,5位取代的硅杂环戊二烯(Silole)系列衍生物进行几何结构优化, 通过计算得到电离能、电子亲和势、空穴抽取能及电子抽取能等相关能量, 并使用TD-DFT方法研究其吸收光谱, 分析相关能量及光谱的变化规律. 采用单组态相互作用(CIS/6-31G*)方法优化得到它们的最低单重激发态(S1)结构, 在此基础上, 使用TD-DFT方法计算对应的发射光谱. 分析2,5位芳基取代硅杂环戊二烯衍生物(DADPS)激发态与基态的结构差异及原因, 研究前线分子轨道的分布情况, 并讨论发光特征及载流子传输性能. 研究结果表明, 激发态结构弛豫主要发生在Silole环和直接与2,5位芳基相连的部位; 前线轨道主要分布在Silole环和2,5位芳基上; 二吡咯取代物有望成为空穴传输材料, 二噻吩取代物和二呋喃取代物有望在发光器件中表现出较高的发光效率.     

1,4-二氢Hantzsch吡啶衍生物的合成及其1H NMR和荧光光谱研究

报道了N-甲基-4-芳基-2,6-二甲基-3,5-二乙酯基-1,4-二氢吡啶(2a-2f),4-芳基-2,6-二苯基-3,5-二乙酯基-1,4-二氢吡啶(3a-3f)及其相应的N-甲基化合物(4a-4f)的合成(芳基p-RC6H4-;R＝OCH3,CH3,H,Cl,CN,NO2).化合物4-芳基-2,6-二甲基-3,5-二乙酯基-1,4-二氢吡啶(1a-1f)可发射较强的荧光,化合物3呈现较弱的荧光,它们的氮甲基产物2和4没有荧光.化合物4氮甲基质子的化学位移值比其相对应的化合物2氮甲基质子的化学位移值向高场移动0.6～0.7.化合物3的4-位次甲基质子的化学位移变化与同碳苯基对位取代基的σ+P有相当好的关联.这些现象反映了化合物2-4的特征构象.     

N-糖基-2-取代-氨基硫脲及N-糖基-N′-取代-联二硫脲类化合物的合成

芳香酸经酯化、肼解 ,合环后再引入肼基 ,得 2 肼基 5 芳基 1,3 ,4 二唑 ( 2 ) ,芳基硫脲经环化、肼解得 2 肼基 4/ 6 取代 -苯并噻唑 ( 3 ) .糖基异硫氰酸酯 ( 1)分别与 2 ,3及N 取代氨基硫脲 ( 4 )发生亲核加成反应 ,制得系列新的N 糖基 2 取代 -氨基硫脲衍生物 5 ,6及N 糖基 N′ 取代 -联二硫脲类化合物 7.所有化合物的结构均经IR ,1HNMR ,MS谱和元素分析证实 .IR谱中 90 0cm-1附近的吸收及1HNMR谱中偶合常数JCl—H=9～ 10Hz ,证明产物为 β 构型     

N-糖基-2-取代-氨基硫脲及N-糖基-N''''-取代-联二硫脲类化合物的合成

芳香酸经酯化、肼解,合环后再引入肼基,得2-肼基-5-芳基-1,3,4-噁二唑(2),芳基硫脲经环化、肼解得2-肼基-4/6-取代-苯并噻唑(3).糖基异硫氰酸酯(1)分别与2,3及N-取代氨基硫脲(4)发生亲核加成反应,制得系列新的N-糖基-2-取代-氨基硫脲衍生物5,6及N-糖基-N'-取代-联二硫脲类化合物7.所有化合物的结构均经IR,1H NMR,MS谱和元素分析证实.IR谱中900cm-1附近的吸收及1H NMR谱中偶合常数JCl-H=9～10 Hz,证明产物为β-构型.     

2,5-二[4-(2-芳基乙烯基)苯基]噁二唑的合成及发光特征

二乙烯联苯及其衍生物是一种可发射蓝光的小分子空穴型有机发光材料, 通过Wittig-Horner反应, 将电子传输型噁二唑环“嵌入”其中, 设计合成了6个2,5-二[4-(2-芳基乙烯基)苯基]-1,3,4-噁二唑化合物. 经光谱分析和元素分析等方法确认了它们的化学结构. IR和UV-vis分析数据表明标题化合物分子结构中的C＝C双键均为反式结构特征. 研究结果表明: 2,5-二[4-(2-对二甲氨基苯基乙烯基)苯基]-1,3,4-噁二唑具有良好的蓝色发光性能; 取代基对标题化合物的UV-vis吸收光谱和发光特性的影响显着.     

N—芳基—N‘—取代噻唑基脲的合成与结构表征

由于植物细胞分裂素在植物生长发育中非常重要的作用 ,一直得到人们的重视 ,但其天然存在量微难以大量应用 ,故人工合成的化学结构类似物相继出现 ,主要有嘌呤类 ,如 6-苄氨基嘌呤 ( 6-BA)等 [1]和脲类化合物 ,如二苯脲类 ( DPU) [2 ]和N-苯基 -N′-( 1 ,2 ,3 -噻二唑 -5 -基 )脲 ( TDZ) [3]。人工合成嘌呤类植物细胞分裂素的结构改造一般以苯并杂环代替嘌呤环或嘌呤环上取代基进行结构变化 ,脲素细胞分裂素结构改造 ,通常是改变 N-取代基的化学结构 ,为寻找化学结构更类似天然植物细胞分裂素的化合物 ,在合成 N-取代苯基 -N′-( 6-苯…     

Spectroscopic Properties of Amine‐substituted Analogues of Firefly Luciferin and Oxyluciferin

Spectroscopic and photophysical properties of firefly luciferin and oxyluciferin analogues with an amine substituent (NH₂, NHMe and NMe₂) at the C6' position were studied based on absorption and fluorescence measurements. Their π‐electronic properties were investigated by DFT and TD‐DFT calculations. These compounds showed fluorescence solvatochromism with good quantum yields. An increase in the electron‐donating strength of the substituent led to the bathochromic shift of the fluorescence maximum. The fluorescence maxima of the luciferin analogues and the corresponding oxyluciferin analogues in a solvent were well correlated with each other. Based on the obtained data, the polarity of a luciferase active site was explained. As a result, the maximum wavelength of bioluminescence for a luciferin analogue was readily predicted by measuring the photoluminescence of the luciferin analogue in place of that of the corresponding oxyluciferin analogue.     

Bioluminescence activity of Latia luciferin analogues: replacement of the 2,6,6-trimethylcyclohexene ring onto the methyl-substituted phenyl groups

A series of Latia luciferin analogues having methyl-substituted phenyl groups instead of the natural 2,6,6-trimethylhexene ring was synthesized and their bioluminescence activity were measured. The Latia luciferase was found to be able to moderately recognize the appropriately methyl-substituted phenyl analogues with the same light production kinetics as that of natural luciferin.     

三氯化氮中氮和氯的化合价模拟研究

采用计算化学模拟方法,在MP2/6-311+g(d),B3LYP/6-311+g(d),HF/6-311+g(d),ωB97XD/6-311+g(d)水平上考察了NCl3的自然布居分析电荷(natural population analysis, NPA电荷)、原子偶极矩校正的Hirshfeld布居电荷(atomic dipole moment corrected Hirshfeld population,ADCH电荷)、分子中的原子理论电荷(atoms in molecules,AIM电荷)和自然电子构型。模拟结果表明,N的化合价为负,而Cl的化合价为正。     

A Dual‐Color Far‐Red to Near‐Infrared Firefly Luciferin Analogue Designed for Multiparametric Bioluminescence Imaging

Red‐shifted bioluminescent emitters allow improved in vivo tissue penetration and signal quantification, and have led to the development of beetle luciferin analogues that elicit red‐shifted bioluminescence with firefly luciferase (Fluc). However, unlike natural luciferin, none have been shown to emit different colors with different luciferases. We have synthesized and tested the first dual‐color, far‐red to near‐infrared (nIR) emitting analogue of beetle luciferin, which, akin to natural luciferin, exhibits pH dependent fluorescence spectra and emits bioluminescence of different colors with different engineered Fluc enzymes. Our analogue produces different far‐red to nIR emission maxima up to λ_max=706 nm with different Fluc mutants. This emission is the most red‐shifted bioluminescence reported without using a resonance energy transfer acceptor. This improvement should allow tissues to be more effectively probed using multiparametric deep‐tissue bioluminescence imaging.     

NAPHTHYL- AND QUINOLYLLUCIFERIN: GREEN AND RED LIGHT EMITTING FIREFLY LUCIFERIN ANALOGUES

In the course of investigations on the possible involvement of the CIEEL (chemically initiated electron-exchange luminescence) mechanism in firefly bioluminescence, we have synthesized two novel firefly luciferin substrate analogues. D-Naphthylluciferin and D-quinolylluciferin were prepared by condensing D-cysteine with 2-cyano-6-hydroxynaphthalene and 2-cyano-6-hydroxyquinoline, respectively. These analogues are the first examples of bioluminescent substrates for firefly luciferase that do not contain a benzothiazole moiety. Firefly luciferase-catalyzed bioluminescence emission spectra revealed that compared to the normal yellow-green light of luciferin (lambda max = 559 nm), the emission from naphthylluciferin is significantly blue-shifted (lambda max = 524 nm); whereas quinolylluciferin emits orange-red light (lambda max = 608 nm). The fluorescence emission spectra, reaction pH optima, relative light yields, light emission kinetics and KM values of the analogues also were measured and compared to those of luciferin. Neither of the analogues produced the characteristic flash kinetics observed for the natural substrate. Instead, slower rise times to peak emission intensity were recorded. It appears that the formation of an intermediate from the analogue adenylates prior to the addition of oxygen is responsible for the slow rise times. The synthetic substrate analogues described here should be useful for future mechanistic studies.     

Simultaneous preparation of four truncated analogues of discodermolide by fluorous mixture synthesis

[structure: see text] Four truncated analogues of the natural product discodermolide were synthesized in a single synthetic sequence. Precursors bearing four different groups at C22, each with a unique fluorous p-methoxybenzyl substituent on the C17 hydroxy group, were mixed and taken through an nine-step sequence. Demixing by fluorous chromatography followed by deprotection and purification provided the individual analogues in 3-7% overall yields and with a savings of 24 synthetic steps. Fluorous mixture synthesis is recommended as a new technique to make multiple natural product analogues in a single multistep synthesis.     

Electronic spectra of α,β-unsaturated ketones — Indole derivatives

The electronic spectra of (3-indolyl)-, (1-methyl-3-indolyl)-, and (6-nitro-3-indolyl)-substituted ,-unsaturated ketones were measured and interpreted. 3-Indolyl and N-methyl-3-indolyl substituents have a considerable bathochromic effect as compared with the phenyl group in the investigated systems as a consequence of the electron-donor effect, which surpasses that for 4-anisyl, 2,4-dimethoxyphenyl, 2-furyl, 2-thienyl, and 2-selenienyl and differs only slightly from 2-pyrrolyl. The introduction of electron-donor substituents into the p position of the benzene ring of 1-(3-indolyl)-3-phenyl-1-propenone causes a red shift of the long-wave absorption band, the difference in frequencies of which correlates with the Hammett substituent constants. Except for compounds containing a nitro group,1-(3-indolyl)-3-aryl-3-propenones and their N-methyl derivatives fluoresce well in alcohol with _max >475 nm.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–953, July, 1972.     

Synthesis of Firefly Luciferin Analogues and Evaluation of the Luminescent Properties

Five new firefly luciferin ( 1 ) analogues were synthesized and their light emission properties were examined. Modifications of the thiazoline moiety in 1 were employed to produce analogues containing acyclic amino acid side chains ( 2 – 4 ) and heterocyclic rings derived from amino acids ( 5 and 6 ) linked to the benzothiazole moiety. Although methyl esters of all of the synthetic derivatives exhibited chemiluminescence activity, only carboluciferin ( 6 ), possessing a pyrroline‐substituted benzothiazole structure, had bioluminescence (BL) activity (λ_max=547 nm). Results of bioluminescence studies with AMP‐carboluciferin (AMP=adenosine monophosphate) and AMP‐firefly luciferin showed that the nature of the thiazoline mimicking moiety affected the adenylation step of the luciferin–luciferase reaction required for production of potent BL. In addition, BL of 6 in living mice differed from that of 1 in that its luminescence decay rate was slower.