Synthesis,absorption spectra studies,solvatochromism and halochromism of polymethine cyanine dyes

New polymethine cyanine dyes, including tetramethine and bis‐tetramethine cyanine dyes derived from benzo[2,3‐b;2′,3′‐b′]bis‐pyrazolo[4,5‐b]‐1,4‐(oxa‐, thia‐ and pyra‐)‐zine‐6,12‐dione, were synthesised. Absorption spectra for all the synthesised cyanine dyes were examined in 95% ethanol. The solvatochromism and halochromism for some selected dyes were investigated in pure solvents and in aqueous universal buffer solutions, respectively. Structural confirmations were carried out through elemental and spectroscopic analysis.     

Synthesis, absorption characteristics and solvatochromism of some novel heterocyclic cyanine dyes

Novel heterocyclic monomethine, bis monomethine, trimethine and bis trimethine cyanine dyes incorporating benzo [2,3-b; , - ] bis furo [3,2-d] pyrazole nuclei were synthesised. The absorption characteristics of the prepared cyanines were studied and determined through measuring their electronic visible absorption spectra in 95% ethanol. The solvatochromism of some of the synthesised dyes was investigated.     

Bright fluorescent dsDNA probes: novel polycationic asymmetric monomethine cyanine dyes based on thiazolopyridine‐quinolinium chromophore

Seven tri‐ and tetracationic monomeric and homodimeric monomethine cyanine dyes based on thiazolo[4,5‐b]pyridinium and quinolinium end groups were synthesised and characterised. The dyes were tested as fluorescent DNA intercalating probes to apply in DNA gel electrophoresis. The DNA samples stained with all dyes from the series demonstrated bright fluorescent signals. DNA fragments were successfully visualised under orange and green filters as well as under standard UV transillumination. Two of the studied dyes revealed higher sensitivity to DNA when compared with the commercial dimeric cyanine dye TOTO‐1. Their sensitivity reached that of the commercial dimeric cyanine dye YOYO‐1, but the emission was shifted to longer wavelengths. These qualities make the dyes suitable to apply in a wide range of medical and scientific analytical methods.     

Synthesis and colour spectroscopic investigation of some hemicyanine dyes

New hemicyanine dyes with a benzo[2,3‐b;2′,3′‐b′]bis‐furo[3,2‐d]pyrazolium nucleus were prepared. Spectroscopic investigations were carried out in 95% ethanol for all the synthesised cyanine dyes and/or in pure solvents which have different polarities for some selected dyes. Structural identification was carried out via elemental analysis, infra‐red and proton nuclear magnetic resonance spectral data.     

Cyanine dyes from polynitro- and poly(trifluoromethylsulphonyl)-benzenes

New monomethine and trimethine cyanine dyes with benzothiazole or indole and polynitro- or poly(trifluoromethylsulphonyl)-substituted benzene rings attached to the ends of the polymethine chain have been synthesised. Atoms of fluorine or methyl groups were introduced to the α-position of the polymethine chain. The influence of nitro and trifluoromethylsulphonyl groups on the colour of these dyes is compared. It is shown that the CF₃SO₂ group is a weaker auxochrome than the nitro group.     

The synthesis and characterization of novel,aza-substituted squarylium cyanine dyes

Several squarylium cyanine dyes derived from benzothiazole, benzoselenazole and quinoline were synthesised and the central four member ring functionalized by substitution of one of the oxygen atoms by benzylamine, aniline, 3-iodoaniline, N,N-dimethylhydrazine and 2-aminosulfonic acid groups. All of the ensuing, novel aza-substituted dyes displayed strong absorption within the range 651–709 nm.     

Synthesis and characterisation of monomethine cyanine dyes based on N-bridgehead heterocycles

In this paper, the synthesis and spectral properties of novel asymmetrical and symmetrical monomethine cyanine dyes are described. Reaction of phenylpyrazolones and oxazolones with acetyl thiourea and/or thiosemicarbazide afforded acetyl intermediate compounds which were then reacted with metal divalent chlorides, followed by reaction with N -methyl hetetrocyclic quaternary salts, to give asymmetrical monomethine cyanine dyes. Reaction of the 5-amino derivative of the intermediate compounds with acetaldehyde followed by reaction with N -methyl hetetrocyclic quaternary salts produced the symmetrical monomethine cyanine dyes. These new compounds were characterised with elemental analyses, visible absorption and infrared spectrometry, and ¹H/¹³C NMR and mass spectroscopy. The correlation between the colour and structure of these dyes was also investigated.     

双羟基七甲川菁染料的合成及其光谱性能研究

通过分子设计,分别以2,3,3-三甲基吲哚和1,1,2-三甲基-1H-苯并[e]吲哚为原料,首先合成两种季铵盐,再分别同2-氯-1-甲酰-3-羟基亚甲基环己烯缩合,利用Suzuki-Miyaura反应实现染料中位C—C偶联,以超过70%的收率制备了4种带有活性羟基的七甲川菁染料。利用核磁和高分辨率质谱对染料结构进行了表征。以乙醇为溶剂,用紫外-可见光谱仪考察了染料的光谱性能。采用电流为13.4 A的高压氙灯为光源,考察了染料的光稳定性。探究了pH对染料颜色的影响,并尝试推论变色机理。结果表明,4种七甲川菁染料均在近红外区产生较强吸收,在无水乙醇中均具有良好的光稳定性。不同pH下,染料的光谱性能研究发现,七甲川菁染料吸收光谱受pH影响较大,在pH=5～7时,染料在近红外区有最佳吸收。     

菁染料和份菁染料溶液的光降解机理的研究

利用UV－Vis吸收光谱仪和光化学反应器,研究了菁染料和份菁染料溶液的光降解动力学,认为染料在乙腈溶液中的光褪色反应服从假一级或零级动力学,利用GC／MS光谱仪检测了染料的光降解产物,与相应的份菁染料相比,携带正电荷的菁染料具有相对较好的光稳定性,研究结果表明,菁染料光降解反应的中间体可能是染料的半氧化态Dye^ ,并利用纳秒级闪光光解技术研究了Dye^ 的瞬态吸收光谱。     

Cyanine dyes of new heterocyclic ring systems: Synthesis and structure-spectra studies

New cyanine dyes including monomethine cyanine dyes (simple cyanine dyes) and trimethine cyanine dyes (carbocyanine dyes) incorporating benzo[2,3-b; 2′,3′-b′]bispyrazolo[4,5-b]-1,4-(oxa-, thia-, and pyra)-zine-6,12-dione were prepared. Structure-spectra studies were carried out via measuring the electronic visible absorption spectra of these dyes in 95% ethanol. Structural confirmations were determined through elemental analysis, IR, ¹H NMR spectroscopy and MS spectral data at the Micro Analytical Center, Cairo University.     

Preliminary studies on the use of cyanines as ligands in dye-affinity chromatography of proteins

An isothiocyanato-functionalised cyanine was synthesised, characterised, immobilised on agarose gel and the dye-affinity adsorbent ability for purifying some standard proteins (e.g. bovine serum albumin, trypsin and chymotrypsin) was analysed. The influence of mobile phase composition on the chromatographic behaviour of these proteins was also studied. A selective interaction between the studied proteins and the immobilised cyanine was obtained.     

菁染料和份菁染料的合成及其溶液的光稳定性研究

利用UV－Vis吸收光谱仪和光化学反应器,研究了菁染料和份菁染料的光降解动力学,研究结果表明,染料在乙腈溶液中的光褪色反应遵循假一级或零级动力学衰减,与相应的份菁染料相比,携带正电荷的菁染料具有相对较好的光稳定性。     

Studies on cyanine dyes. III. Synthesis of 2-styryl-5-cyanonaphthoxazole cyanine dyes

New types of styryl cyanine dyes (V) containing two different heterocyclic nuclei were prepared through the reaction of 5-cyanonaphth[1,2-]-oxazole-2-carboxaldehyde (IV) with α-picoline and quinaldine ethiodides. Other styryl bases (III) were also obtained as reaction products between 2-methyl-5-cyanonaphth[1,2-d]oxazole (I) and aromatic aldehydes in the presence of anhydrous zinc chloride. Structural configurations of the synthesised compounds were identified by u.v. and i.r. spectra determination.     

Synthesis and antimicrobial activity of certain novel monomethine cyanine dyes

A series of novel monomethine cyanine dyes were synthesized by using 3-methyl-5-substituted-1-phenyl-pyrano[2,3-c]pyrazole derivatives 2a–c. Reaction of equimolar ratios of 2a–c with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 3a–c. Reaction of compound 5 with 2(4)-methyl heterocyclic quaternary salts gives monomethine 6a–c. Condensation reaction of equimolar ratios of compounds 7 and 9a,b with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 8a–c and 10a,b respectively. The new synthesized monomethine cyanine dyes were identified by elemental analyses, IR, ¹H-NMR and Ms spectral data. The electronic absorption spectra in ethanolic solution of novel monomethine cyanine dyes were measured and the antimicrobial activity of some selected monomethine cyanine dyes was discussed.     

菁染料与溴化银相互作用性质的研究

本文用计时电位法及电位滴定研究了十六种不同染料与溴化银之间的相互作用,进一步证明了具有离域π-电子的菁染料才能与卤化银形成络合物的论点。从得到的平衡常数K表明,固体表面上的卤化银-染料与溶液中银离子-染料具有相同键性质,都是银离子与染料离域π-电子作用的结果。     

菁染料和份菁染料薄膜的光稳定性研究

利用UV－Vis吸收光谱仪和光化学反应器研究了菁染料和份菁染料薄膜的光降解动力学。与相应的份菁染料相比，携带正电荷的菁染料薄膜具有相对较好的光稳定性。运用量子化学中的SCF－MO－PM3方法，全优化计算了这些染料的分子几何构型和电子结构，并解释了染料的光稳定性与其分子结构的关系。     

菁染料单分子膜覆盖的铂电极的电化学特性

L-B膜作为一种单分子膜技术已经得到了广泛的应用。最近很多人用电化学方法研究覆盖有L-B膜电极的特性。许多工作证明了脂肪酸L-B膜具有很强的抑制离子透过和抑制电子隧道电流的能力。而不具备这种性能的L-B膜,则被归之于膜中含有大量针孔所致。Kuhn曾在脂肪酸L-B膜中引入带有共轭双键的偶氮化合物。Zaba     

照相染料还原电位的研究

本文测定了八个照相染料在不同pH条件下的还原电位。发现其中一些增感染料的还原电位与其溶液的pH值无关,而一些减感染料依赖于pH值的变化。本文用染料质子化机理分析了这些结果。     

近红外吸收菁染料光氧化反应机理的研究

本文选择了三种分子结构相同而母核杂原子不同的近红外吸收菁染料，对它们的光谱性能特征及光氧化稳定性能进行了研究。结果表明，具有三各步同母核杂原子的菁染料，其光氧化稳定怀顺序为：苯并恶唑〉苯并噻唑〉苯并硒唑，通过猝灭实验给出，在三咱菁染料的光氧化反应机制中，具有反应活性的单线态氧和超氧负离子同时存在，其中单线态氧是导致菁染褪色的主要因素。     

Synthesis of novel tetracationic asymmetric monomeric monomethine cyanine dyes – highly fluorescent dsDNA probes

Quaternisation of monomethine cyanine dyes bearing haloalkyl chains, with the appropriate monoquaternised 1,4‐diazabicyclo[2.2.2]octane derivatives, yielded novel tetracationic asymmetric monomeric monomethine cyanine dyes belonging to the thiazole orange family. The optimal conditions for this reaction were investigated. The longest wavelength absorption maxima of the studied dyes are in the region 504–507 nm. The molar absorptivities of the target dyes are high, with values between 70 500 and 99 500 l mol^?1 cm^?1. The fluorescence intensity and the fluorescence quantum yields of the free dyes in solution or in the presence of double‐stranded DNA were determined using thiazole orange for comparison. The dyes are suitable for nucleic acid detection and have a high binding affinity, attributable to their four positive charges.