Interaction of Polymethine Dyes with Detonation Nanodiamonds

Among cationic, anionic, and merocyanine polymethine dyes, the binding to detonation nanodiamond (DND) colloid particles in hydrosol occurs only for negatively charged dye species. This, in view of the positive ζ-potential of the DND used in this study, suggests the predominance of electrostatic interactions over other intermolecular forces in such systems. Indeed, after decorating the merocyanine and the cationic dye by one and two negatively charged sulfopropyl groups, respectively, so that the net charge of their colored species becomes negative, the compounds also demonstrate affinity to the DND particles. In all cases, the binding of dyes to DND is accompanied by a decrease in fluorescence intensity and a bathochromic shift of their absorption and fluorescence bands. A quantitative study of the dyes adsorption on the DND nanoparticles as performed using the Küster-Freundlich and Langmuir equations reveals some peculiarities of their attaching to the DND aggregates and allows estimating the specific area of the DND particles at a concentration of 0.0212 wt/vol %.     

A Spectroscopic Study on the Interaction of Polymethine Dyes with Collagens

It was shown that collagens stimulated J aggregation of anionic carbocyanine dyes with sulfonate groups, which themselves can form J aggregates in aqueous solutions. The spectral properties of J aggregates formed in the presence of collagens differ from those of the aggregates in the absence of additives. The J aggregation also depends on the type of collagen used.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 4, 2005, pp. 275–279.Original Russian Text Copyright © 2005 by Tatikolov, Panova.     

Fluorescence Properties of Thiacarbocyanine Dyes at Low Temperatures

Measurements were carried out for time-resolved fluorescence spectra of dye solutions containing thiacarbocyanine and its derivatives with ethylene and vinylene bridges in the polymethine chain. At low temperature, an additional band appears in the spectrum related to an intramolecular electronic transition. Analysis of the transition lifetimes and a quantum-chemical model indicated that this transition should be attributed to a short-lived asymmetrical component formed along with the symmetrical component upon relaxation of the excited state but not appearing at room temperature due to conformational transformations.     

Spiro-Azoles Thiazolidinone in the Synthesis of Polymethine Cyanine Dyes

A series of some spiro azoles (pyrazolone, oxazolone, and/or imidazolone) inconjucton with heterocyclic thiazolidinone derivatives were prepared as starting materials in the synthesis of polymethine cyanine dyes. Reaction of spiro 2-formyl (oxime) azoles thiazolidinone derivatives with equi- and/or molar ratios of 2(4)-methyl substituted heterocyclic quaternary salts afforded the corresponding compound pentamethine, aza-mero cyanine, and azapentamethine cyanine dyes respectively. Elemental analyses, IR, 1 H-NMR, and mass-spectra identified the new spiro heterocyclic compounds and polymethine cyanine dyes. The visible absorption spectra of all new polymethine cyanine dyes were investigated.     

计时电位法研究照相染料与溴化银晶体的相互作用

本文以电沉积在银电极上的溴化银为研究对象,用计时电位法研究了照相染料与溴化银晶体之间的相互作用。结果表明,染料对溴化银过渡时间、还原电位和电还原惰性物生成量均有显著影响,并且生成的电还原惰性物量的多少或平衡常数的大小与照相染料对溴化银乳剂感光度之间有一定的关系。     

照相光谱增感染料在溴化银沉淀表面的吸附及吸附热测量

用离心分离法得到25℃菁染料Ⅱ和Ⅲ分别在几种溶剂的溴化银分散系中的吸附等温线;记录了染料溶液的吸收光谱和吸附态染料的反射光谱。采用精密量热技术得到25±0.01℃溴化银从DMF-水溶液中吸附染料Ⅱ等位摩尔吸附热为-(3.18±0.09)KJ/mol(θ=0.87)。还对从DMF溶液中吸附染料Ⅱ的体系绘制了以单位溴化银表面的吸附热表示的吸附等温线,表明用精密量热技术可以研究染料的吸附过程。     

Equilibrium Geometry of Symmetrical Polymethine Dyes in the Solitonic Excited State

The optimized geometry in the excited state of the ions of polymethine dyes R^±—(CH=CH) _n —CH=R with the pyridinium residue and its carbo- and heteroanalogs in the excited state was calculated by quantum-chemical methods in the AM1 approximation. It was found that in addition to the symmetrical solution of the Hamiltonian there is an unsymmetrical soliton state. Significant alternation of the CC bond lengths at one end of the chain in the solitonic state explains the marked decrease in the quantum yields of fluorescence in the long molecules as a result of the decreased barriers of the conformational transformations.     

Reaction of Silver Metaborate with Trimethyltin Bromide

The reaction between trimethyltin bromide and silvermetaboratc leads to the formation of trimethyltin metaborate, (CH₃)₃SnBO₂, and AgBr. The properties of the isolated new trimethyltin metaborate have also been studied. U.V. and I.R. spectra of (CH₃)₃SnBO₂ has also been recorded.     

几种卟啉在化学还原沉积银膜上的表面增强拉曼光谱特征

应用 Ｊｏｂｉｎ－Ｙｖｏｎ Ｕ—１０００型拉曼光谱仪和ＬＡＢＲＡＭＩ型拉曼光谱系统研究了 ３种卟啉ＴＯＨＰＰ、ＴａｍＰＰ和ＴＳＰＰ在化学还原沉积法制备的银膜上的ＲＳ和ＳＥＲＳ光谱特征。结果表明：化学还原法制备的银膜可以作为这几种卟啉的拉曼增强活性载体。这３种卟啉在获谱的过程中都形成二聚态化合物和发生银离子搀和作用，较长的放置和测谱时间有利于银离子的搀和。     

超细Ag颗粒对葡萄糖氧化酶生物传感器响应灵敏度的增强效应

生物传感器在临床医学、环境和食品工业等方面都有重要的用途［１］,且由于其具有体积小、精度高、灵敏度好和便于现场测定等优点,已成为当前研究的热点课题之一．其中研究得较多的是氧化酶电流型生物传感器,特别是介体型,由于其响应快,灵敏而倍受重视．现已报道的可...     

Al-Mg MMH溶胶和钠土悬浮体的相互作用机理

通过流变参数、电泳淌度和pH值的测定,研究了无机盐(CaCl₂、KCl、NaCl)和pH值对铝镁混合金属氢氧化物与钠土悬浮体间相互作用的影响。发现随着混合金属氢氧化物含量的增加,钠土体系的pH值逐渐降低,而动切力(YP)先上升,经最大值后逐渐下降;当钠土体系为NaCl所饱和时,相同混合金属氢氧化物加量下YP的上升幅度明显减小,在实验混合金属氢氧化物浓度范围内,YP未出现峰值。混合金属氢氧化物/钠土体系的YP随pH值的变化曲线呈抛物线形,加入相同浓度的无机盐,△YP、△pH(绝对值)按CaCl₂KCl～NaCl次序递减。     

The Effect of a Constant Electric Field on the Absorption Spectra of Polymethine Dyes

The intensities of the long wavelength absorption bands of symmetrical and unsymmetrical polycarbocyanines in polymer films are redistributed in a constant electric field. This redistribution depends in a regular manner on the chemical structure of the dyes. The spectroscopic effects are interpreted via a change in the probability of the vibronic transitions caused by redistribution of the electron density in the chromophore of the dye in the external electric field.     

Effect of the Structure of Polymethine Dyes on Their Photovoltaic Properties in Polymer Films

Theoretical and Experimental Chemistry - The photovoltaic properties of a wide selection of structures based on cationic and anionic polycarbocyanines in polymeric matrices were investigated. It...     

甲酸盐掺杂立方八面体溴化银乳剂颗粒的增感效应研究

使用反馈式微机控制双注乳化仪,制备了甲酸根离子掺杂于颗粒次表面的立方八面体溴化银微晶乳剂.经计算此类颗粒上的(100)面与(111)面之比约为2:3.感光性能测试结果表明,甲酸根掺杂乳剂,无论是原始乳剂,还是经过化学增感,或染料光谱增感后的乳剂,其感光度都要明显高于相应的参考未掺杂乳剂(S_d/S_o≈2),而灰雾水平则无明显增长.     

酸性染料在银溶胶上吸附状态的表面增强拉曼光谱研究

表面增强拉曼光谱技术 (SERS)能从分子水平上直接提供表面分子结构和动态过程等重要信息 ,被广泛地用于各种物质在金、银、铜等贵金属表面的吸附机理研究 ;本文通过对不同浓度的酸性黑和酸性红在银溶胶上的表面增强拉曼光谱的研究 ,探讨了浓度对其在银溶胶表面吸附状态的影响 ;结果表明 ,酸性黑和酸性红均为5×10-4 mol/L时 ,在银溶胶表面上发生吸附状态改变 ,并形成一个满单分子层 ,表面拉曼信号最强。     

草酸根掺杂立方体溴化银乳剂颗粒的增感效应研究

使用反馈式微机控制双注乳化仪,在晶体生长过程中一定时间内,加入一定量的草酸盐,制得了草酸根离子处于晶体颗粒次表面的立方体溴化银微晶乳剂.对其实验过程的考察和感光性能的测试结果表明,(1)草酸根掺杂于次表面的溴化银乳剂与未掺杂乳剂相比较,无论是原始乳剂,还是经过化学增感,或用染料进行光谱增感后的乳剂,感光度都有明显提高(S_d/S₀≥1.5),有明显的增感效应;(2)无论是原始乳剂,还是经过化学增感,或光谱增感后的乳剂,草酸根掺杂立方体溴化银乳剂颗粒的灰雾水平都不高;(3)草酸根掺杂立方体溴化银颗粒与甲酸根掺杂的溴化银乳剂相比,产生的增感效应相差不大;(4)与甲酸根掺杂立方体溴化银颗粒相比,草酸根掺杂立方体溴化银颗粒的制备方法明显较前者要简单得多,颗粒形状也优于前者.     

草酸根掺杂板状溴碘化银颗粒乳剂的增感效应研究

使用反馈式微机控制双注乳化仪,在晶体生长过程中一定时间内,加入一定量的草酸盐,制得了草酸根离子处于晶体颗粒次表面的板状溴碘化银微晶乳剂.对其实验过程的考察和感光性能的测试结果表明:1)草酸根掺杂于次表面的溴碘化银乳剂与未掺杂乳剂相比较,经过化学增感后,或光谱增感后的乳剂,其感光度有明显提高(Sd/S0≥1.5),即具有明显的增感效应;2)无论是经过化学增感,还是经光谱增感后的乳剂,草酸根掺杂溴碘化银颗粒乳剂的灰雾水平都不高.     

耐尔蓝A在银溶胶上的表面增强拉曼光谱特征

研究了在不同耐尔蓝Ａ浓度，银溶胶，激发波长和ｐＨ值以及碘离子存在下，耐尔蓝Ａ在银溶胶上的表面增强拉曼光谱特征。