噻菁染料的合成

本实验合成了6个二磺酸盐的水溶性噻菁染料,并通过UV-vis、^1H NMR、IR谱图和元素分析给予确定。从紫外可见光谱可看出,苯环上的取代基影响染料的最大吸收(λ~m~a~x)和摩尔消光系数ε~m~a~x。     

卤化银乳剂颗粒上不对称菁染料J-聚体荧光的研究

光谱增感机理的研究是感光科学中的一个重要课题Gilman^[1]和Kuhn等^[2]曾经提出光谱增感的电子转移和能量传递理论。随着现代谱学手段的出现,为人们了解光谱增感的初始过程提供了条件。近年来,电子转移的机理已被广泛接受,并用来解释与光谱增感有关的各种现象。但在ns~ps范围内的光谱增感动力学方面的研究还不多见。Dahne认为光谱增感不仅决定于染料与卤化银的能级关系,而且是由动力学控制的^[3],激发态染料向卤化银导带注人电子的电子转移过程与辐射及其他无辐射去活过程是竞争的^[4]我们通过对两种不对称的苯并咪哇唾碳著染料在AgBrI乳剂颗粒上吸附形成的J一聚体的荧光性质的研究,以求深人了解光谱增感的电子转移机理及其动力学过程,无疑是有重要意义的。     

浅谈菁染料及其研究前景

主要介绍菁染料的结构、性质和光谱增感过程的机理,探求增感染料未来的发展方向。     

TiO_2胶体对菁染料荧光的影响

用紫外 -可见光谱及荧光光谱研究了吸附在TiO2 胶体表面上的两种典型菁染料的光物理性质。吸收光谱表明染料基态分子存在着两种异构体;荧光实验表明TiO2 胶体对菁染料荧光发射强度有增强作用。这是由于染料分子被TiO2 胶体吸附后 ,其分子内的扭转运动受阻 ,从而单重激发态染料分子内扭转运动无辐射跃迁量子效率减少所致。文中还讨论了染料结构对染料 -TiO2 体系荧光发射的影响。     

TiO2胶体对菁染料荧光的影响

用紫外－可见光谱及荧光光谱了吸附在ＴｉＯ２胶体表面上的两种典型菁染料的光物理性质。吸收光谱表明染料基态分子存在着两种异构体;荧光实验表明ＴｉＯ２胶体对菁染料荧光发射强度增强作用。这是出于染料分子被ＴｉＯ２胶体吸附后,其分子内的扭转运动受阻。从而单重激发态染料分子内扭转运动无辐射跃迁量子效率减少所致。文中还讨论了染料结构对染料－ＴｉＯ２胶有附后,其分子内的扭转运动受阻,从而单重激发态染料分子内扭转运     

短波长菁染料对氯化银乳剂的光谱增感作用

本文利用紫外 可见吸收光谱、光谱曝光等手段研究了5种短波长菁染料,比较了它们在氯化银乳剂上的光谱增感作用,得出3种较好的短波长增感染料,并研究它们在氯化银颗粒上的吸附行为.结果表明,这3种染料在氯化银颗粒上均有吸附,并能有效地提高氯化银乳剂在短波长区的感光度.     

若干全极性三核菁染料超增感机理的研究

若干全极性三核菁染料超增感机理的研究张金龙，朱正华，陈廉生（华东理工大学精细化工研究所上海２００２３７）关键词染料正穴，电子顺磁共振，超增感超增感组合是提高增感效率的重要手段，在影像科学和技术领域中占有十分重要的地位，本文新研究的是以全极性（Ｈｏｌｏ...     

含取代基碲碳菁染料的研究

本文报道了含取代基碲碳菁染料(8a～b)的合成方法。4－氯苯胺用等摩尔的乙酸汞、氯化锂及过量的乙酸酐处理可高收率地得到芳基氯化汞(2)。2 在冰乙酸中与等摩尔的四氯化碲回流生成3(内盐)。以水合肼还原3得到化合物4,后者可进一步用硼氢化钠还原并用碘甲烷烷化生成5。化合物6可在不同条件下分别由3、4或5得到。在碘甲烷或碘乙烷作用下,6可以烷基化生成季铵盐(7a～b),后者与原甲酸乙酯在乙酸酐中缩合即生成对称的碲碳菁染料(8a～b)。对染料的可见吸收光谱也进行了讨论。     

菁染料在TiO2胶体表面光诱导的电子转移

本文用紫外-可见光谱及荧光光谱研究了吸附在TiO₂胶体表面上的染料1,1'-二乙基-3,3'-二磺丁基-5,5'-二氰基咪碳菁与胶体间发生的光诱导电子转移过程。荧光实验表明,菁染料荧光发射强度随着体系中TiO₂胶体浓度的增加而降低,这是由于电子从染料的激发单重态注入到TiO₂的导带所致。通过染料荧光寿命的测定得到光诱导电子转移速率常数K_et约为4×10₈s^-1。     

噻菁染料的合成及吸收光谱的研究

合成了阳离子型、两性离子型和阴离子型的噻菁染料,对它们的结构进行了表征,并研究了染料的结构(阴离子和取代基的改变) 对吸收光谱的影响。     

Tuning the photoinduced electron transfer in near-infrared heptamethine cyanine dyes

An efficient photoinduced electron transfer (PET) system in near-infrared region was described. The PET in heptamethine cyanine dyes was tuned by changing the electron-donating ability of the substituent at the central position of the polymehine chain. 4-Aminophenylthio-substitution led to an efficient PET and the lowest fluorescence quantum yield. The acetylation, protonation or transition metal cation coordination of the amino group could recover fluorescence greatly via suppressing the PET.     

Simple reagent for the synthesis of oligonucleotides labeled with 3,3,3′,3′-tetramethyl-2,2′-indodicarbocyanine

Synthesis of a phosphoramidite reagent for the preparation of oligonucleotides labeled at the 5′-end with a fluorescent dye, 3,3,3′,3′-tetramethyl-2,2′-indodicarbocyanine, is described. The efficiency of this reagent is confirmed by the synthesis of several labeled oligonucleotides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 154–158, January, 2006.     

不同取代基的噻碳菁和吲哚碳菁染料对其在溴化银微晶上吸附能力及形成J-聚集体尺寸分布的影响

本文研究了5-位不同取代基的噻碳菁和吲哚碳菁染料对其在立方型颗粒和T-颗粒溴化银微晶上吸附能力的影响,并采用ACFEM(Analytical Color Fluore scence Electron Microscopy)研究了上述结构染料对其吸附在溴化银微晶所形成的J-聚集体尺寸分布的影响。实验结果表明,对吲哚碳菁染料来说,立方体溴化银微晶表面的吸附能力较T-颗粒溴化银微晶表面的吸附能力强;但对噻碳菁染料来说则相反,它们在T-颗粒溴化银微晶表面的吸附能力较立方体溴化银微晶表面的吸附能力强。另外,对5-位不同取代基的噻碳菁染料而言,无论是在立方型颗粒或T-颗粒溴化银微晶上的吸附能力来说,含取代基(无论4-取代基是吸电子型还是推电子型)的噻碳菁染料较未取代的噻碳菁染料强;而5-位取代基是吸电子型的噻碳菁染料更有利于其吸附在T-颗粒溴化银微晶表面。此外,本文还进一步证明了溴化银微晶表面上染料J-聚集体的生长过程是符合奥斯瓦尔特成熟过程的。吲哚碳菁染料在T-颗粒溴化银微晶上形成的J-聚集体的平均尺寸明显大于在立方体溴化银微晶上形成的J-聚集体的平均尺寸。吸附在立方体溴化银微晶上的5-不同取代基的噻碳菁染料对其形成J-聚集体尺寸分布的影响的研究结果表明,含取代基(-CH₃,-Ph,-Cl)的噻碳菁染料形成的J-聚集体的尺寸分布几乎相同,但与未取代的噻碳菁染料形成的J-聚集体的尺寸分布明显不同;5-位含取代基的噻碳菁染料形成的J-聚集体平均尺寸大于未取代的噻碳菁染料的。     

光谱增感染料798的聚集效应与在AgBr上的吸附

用吸收光谱和反射光谱技术研究了黑白片感红染料７９８（３．３’－二羟乙基－５,５’－二甲氧基－９－乙基－噻碳菁氯盐）在甲醇、水及ＫＢｒ水溶液中的聚集效应和吸附于ＡｂＢｒ表面的吸附态性质。其在甲醇中以单分子态存在的最大吸收波长λｍａｘ为５６０ｎｍ。     

Boron-diindomethene (BDI) dyes and their tetrahydrobicyclo precursors--en route to a new class of highly emissive fluorophores for the red spectral range

The X-ray crystallographic, optical spectroscopic, and electrochemical properties of a newly synthesized class of boron-diindomethene (BDI) dyes and their tetrahydrobicyclo precursors (bc-BDP) are presented. The BDI chromophore was designed to show intensive absorption and strong fluorescence in an applicationary advantageous spectral range. Its modular architecture permits fusion of a second subunit, for example, a receptor moiety to the dye's core to yield directly linked yet perpendicularly prearranged composite systems. The synthesis was developed to allow facile tuning of the chromophore platform and to thus adjust its redox properties. X-ray analysis revealed a pronounced planarity of the chromophore in the case of the BDIs, which led to a remarkable close packing in the crystal of the simplest derivative. On the other hand, deviation from planarity was found for the diester-substituted bc-BDP benzocrown that exhibits a "butterfly"-like conformation in the crystal. Both families of dyes show charge- or electron-transfer-type fluorescence-quenching characteristics in polar solvents when equipped with a strong donor in the meso-position of the core. These processes can be utilized for signaling purposes if an appropriate receptor is introduced. Further modification of the chromophore can invoke such a guest-responsive intramolecular quenching process, also for receptor groups of low electron density, for example, benzocrowns. In addition to the design of various prototype molecules, a promising fluoroionophore for Na+ was obtained that absorbs and emits in the 650 nm region and shows a strong fluorescence enhancement upon analyte binding. Furthermore, investigation of the remarkable solvatokinetic fluorescence properties of the "butterfly"-like bc-BDP derivatives suggested that a second intrinsic nonradiative deactivation channel can play a role in the photophysics of boron-dipyrromethene dyes.     

Water-soluble cyanine dyes for biological microchip technology

Novel indodicarbocyanine dyes were obtained and their spectroscopic characteristics were determined. For equal concentrations of the dyes, the relative fluorescence efficiency was measured at the excitation wavelengths λ = 635 and 655 nm and the emission wavelengths λ = 670 and 690 nm, respectively. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2355–2359, December, 2007.