新型香豆素类荧光探针的合成及其对Cu~(2+)的识别性能

以2-羟基-4-甲氧基苯甲醛和丙二酸二乙酯为起始原料,设计并合成了一种新型的Cu~(2+)荧光探针7-甲氧基-2-氧代-N-[2-(苯基氨基)乙基]-2H-色烯-3-甲酰胺(NPC),其结构经~1H NMR,~(13)C NMR,MS(EI)和元素分析表征。并研究了室温下,NPC在乙醇和水的混合溶液中对Cu~(2+)的识别性能。结果表明:NPC对Cu~(2+)表现出荧光猝灭效应,具有对Cu~(2+)的选择性识别性能。     

新型1,8-萘二酰胺荧光探针的制备及其对Cu~(2+)检测应用

以4-溴-1,8-萘甲酸酐、水合肼、4-(2-氨乙基)吗啉和水杨醛作为原料,合成了一种1,8-萘二酰胺的新型荧光探针(L),并通过~1H NMR,~(13)C NMR,FT-IR等分析手段对其结构和组成进行表征。研究发现L对Cu~(2+)具有荧光识别作用且受其它离子干扰小的优势。探针L的荧光强度与Cu~(2+)浓度(2.0~9.0μmol/L)呈较好的线性关系,检出限为47 nmol/L。将其对河水样品和药品进行Cu~(2+)加标回收实验,回收率均大于92.0%,RSD小于2.0%,探针L能够应用于这些样品中微量Cu~(2+)的测定。     

一种基于吗啉衍生物的Fe3+/Cu2+荧光探针

以9-蒽醛为荧光基团,吡唑和吗啉为识别基团,合成了一种荧光分子探针4-((3-(1-苯基-5-吡啶基-4,5-二氢-1H-吡唑-3-基)蒽-9-基)甲基)吗啉(L)。其结构经1H NMR、13C NMR表征,利用荧光发射光谱和紫外吸收光谱研究其离子识别性能。结果表明,探针L对Fe~(3+)和Cu~(2+)具有较强的选择性识别性能,荧光量子产率分别从0.47降到0.21和0.14;探针L的溶液颜色分别从淡黄色变为棕褐色和蓝色,裸眼可判断探针L选择性识别Fe~(3+)和Cu~(2+)。另外,根据Fe~(3+)、Cu~(2+)和H+不同组合时探针L的量子产率构建了分子水平上的三输入"NOR"逻辑门电路。     

近红外Cu2+比率荧光探针合成及其细胞成像

基于罗丹明染料和菁染料衍生物,设计合成了一种新型近红外比率Cu~(2+)荧光探针(RCy7)。通过核磁共振和质谱对其结构进行了表征。详细研究了该荧光探针对Cu~(2+)的光学识别性能。在体积比为1∶1的乙腈/Tris-HCl(20 mmol/L,pH=7.2)缓冲溶液中,探针RCy7显蓝色且在722 nm波长处有较强的荧光发射峰,随着Cu~(2+)的加入,探针在722 nm波长处的最大发射峰蓝移到577 nm,溶液颜色也从蓝色变为粉红色。该探针对Cu~(2+)的识别具有高选择性,而且可在较宽的pH(5.5～11.3)范围内实现对Cu~(2+)的检测。Cu~(2+)的浓度在0～1.0×10~(-5) mol/L范围内与探针的荧光强度比值(I_(577)/I_(722))呈良好的线性关系,相关系数R~2=0.9928,检出限为1.09×10~(-8) mol/L。此外,探针RCy7具有良好的细胞膜透性,被成功地用于活HeLa细胞中Cu~(2+)的荧光成像。     

基于杯[4]冠醚的1,3,4-噁二唑荧光探针的合成及对金属离子的识别

分别以2-苯基-5-(2-吡啶基)-1,3,4-噁二唑及2,5-二苯基-1,3,4-噁二唑为荧光基团,设计合成了基于杯[4]冠醚结构的荧光探针分子1a和1b;利用核磁共振氢谱(~1H NMR)、碳谱(~(13)C NMR)及高分辨质谱(HRMS)表征了其结构.采用紫外-可见光谱及荧光光谱考察了探针分子1a和1b对碱金属离子(Na~+,K~+,Cs~+)、碱土金属离子(Mg~(2+),Ca~(2+))及过渡金属离子(Mn~(2+),Co~(2+),Ni~(2+),Cu~(2+),Zn~(2+),Cd~(2+),Ag~+)的识别作用.结果表明,Na~+可使探针分子1a的二氯甲烷溶液荧光强度显著增强,K+和Cs~+对探针分子1a的荧光强度几乎无影响,而Ca~(2+)及所有过渡金属离子均可有效猝灭探针分子1a的荧光.探针分子1b对于碱金属离子的识别作用与探针分子1a相似,但其与过渡金属离子的络合作用弱于探针分子1a.根据核磁共振表征结果讨论了金属离子与荧光探针的络合位点.     

基于咔唑-席夫碱的高选择性裸眼和荧光识别Cu~(2+)的探针

合成了一种新型基于咔唑-席夫碱识别Cu~(2+)的荧光探针L.利用紫外-可见和荧光光谱研究了探针L对阳离子的识别性能.实验结果显示,当加入Cu~(2+)时,探针L的CH_3CN溶液显示出明显的颜色变化,由黄色变为无色.这表明,利用探针L可裸眼识别Cu~(2+).通过荧光光谱分析实验发现,在CH_3CN溶剂中,探针L对Cu~(2+)具有较高的选择性和灵敏度,其荧光强度随着Cu~(2+)的浓度增大而逐渐增强,不受其它金属离子影响,抗干扰能力强.探针L与Cu~(2+)的结合常数为1.38×10~4 L/mol,检测限为2.34×10~(-7) mol/L,低于世界卫生组织(WHO)规定的饮用水中Cu~(2+)的最大含量20mmol/L.探针L在检测环境中的Cu~(2+)含量方面具有潜在应用价值.     

双罗丹明类衍生物荧光探针的合成及对Cu~(2+)的识别

设计并合成了一种可检测Cu~(2+)的新双罗丹明类衍生物荧光增强型分子探针(RG1),并用核磁和高分辨质谱(HRMS)对其结构进行了表征。通过紫外-可见光谱和荧光光谱研究了该荧光分子探针对Cu~(2+)的识别性能,结果表明:在体积比为1∶1的乙腈-水(10mmol/L Tris-HCl,pH=7.2)溶液体系中,探针RG1本身无色且荧光很弱,加入Cu~(2+)后,探针在553nm处出现强的荧光发射峰,溶液颜色从无色变为粉红色,对Cu~(2+)表现出好的选择性。此外,该探针可在较宽的pH范围(5~10)内直接检测Cu~(2+)的浓度。结果表明,Cu~(2+)浓度在3.0×10~(-6)~1.5×10~(-5)mol/L范围内与探针的荧光强度呈良好的线性关系,Cu~(2+)检出限为3.31×10~(-7)mol/L。同时对河水进行加标回收实验,得到了良好的回收率。     

香豆素类双酰腙荧光探针的合成及对Cu~(2+)的识别性能（英文）

设计合成了2种以香豆素为荧光团、酰腙为识别基团的双香豆素双酰腙类荧光探针,并对其进行了结构表征及光谱性能研究。结果表明,探针对Cu~(2+)具有高选择性和高灵敏度,表现出明显的荧光猝灭效应,探针与Cu~(2+)以1∶2的结合比相互作用,对Cu~(2+)检测限为10~(-9)mol/L。     

纯水中检测汞离子与银离子的菲啰啉类荧光探针

合成了菲啰啉类化合物探针1,并通过核磁共振波谱(NMR)、质谱(MS)、红外光谱(IR)对其结构进行了表征。利用荧光发射光谱考察了探针1对Hg~(2+)及Ag~+的识别性能。结果表明,探针1在纯水介质中以荧光猝灭的方式识别Hg~(2+)和Ag~+,其结合比分别为1∶1和2∶1,检测的线性范围分别为9.0×10~(-7)～1.1×10~(-5)和8.0×10~(-7)～7.0×10~(-6) mol/L,相关系数(r~2)均大于0.99,检出限均低至10~(-8)mol/L。根据探针1识别前后荧光强度的剧烈变化,建立了裸眼检测Hg~(2+)和Ag~+的可视化分析方法。通过等温量热滴定与~1H NMR滴定考察了识别过程的热力学参数和作用机理。该研究对生物体及环境领域中Hg~(2+)和Ag~+的实时监测具有潜在的应用价值。     

高选择性快速检测Cu~(2+)的水杨酰腙型探针的合成及在逻辑门和吸附中的应用

以4-溴代三苯胺、5-甲醛基呋喃-2-硼酸和水杨酰肼为原料,设计合成了一种新型的可快速识别Cu~(2+)的席夫碱类荧光探针分子(HJW-2),并通过~1H NMR,~(13)C NMR和HR-MS对其结构进行了表征.基于分子内电荷转移机理(ICT),HJW-2展现出优异的溶剂效应,对Cu~(2+)具有快速识别、高选择性和专一性,检测限低至9.8×10~(-8) mol·L~(-1),响应时间仅需10 s,通过~1H NMR滴定实验和HRMS以及密度泛函理论计算,对其可能的响应机理进行了探究.HJW-2已成功用于分析不同水样中的Cu~(2+)浓度,并且利用HJW-2在乙二胺四乙酸(EDTA)存在时的可逆性,以Cu~(2+)和EDTA为化学输入,构建了分子逻辑门.在实际应用中,通过聚丙烯酰胺(PAM)掺杂HJW-2 (PAM-HJW-2)能实现对Cu~(2+)的高效吸附,去除率达到99.94%,并通过扫描电子显微镜(SEM)和X光微区分析(EDS)对PAM-HJW-2吸附前后的微观形貌和元素变化进行了对比.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.