5260-36-6Relevant academic research and scientific papers
Stability and Self-Association of styryl hemicyanine dyes in water studied by 1H NMR spectroscopy
Boecker, Marcel,Haese, Constantin,Mondeshki, Mihail,Vasilev, Aleksey
, (2022/02/16)
The stability in water of five styryl hemicyanine dyes containing benzoxazole, benzothiazole, benzoselenazole and oxazolopyridne rings with different substituents at different pH values has been investigated. All compounds are stable at acidic and neutral pH, however, at basic pH the oxazole dyes undergo a ring opening reaction. The stability at basic pH is increased by substituting the benzooxazolium with oxazolopyridium function in the oxazole dyes 3a and 3e. 1H and 1H DOSY solution NMR spectroscopy prove that slight structural changes result in significant differences in the process of self-association. The association constants for dimerization have been determined by curve fitting the concentration dependent 1H NMR spectra based on the isodesmic model. Van't Hoff analysis has been used to determine the thermodynamic parameters of the self-association process. The aggregation in water decreases with decreasing electronegativity and increasing the charge delocalization in the row (E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[d]oxazol-3-ium iodide (3a), (E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[d]thiazol-3-ium iodide (3b), (E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[1,3-d]selenazol-3-ium iodide (3d) in the oxazole/thiazole/selenazole analogues. Introducing methyl groups in the benzothiazole ring enhances stacking effects in water due to stronger hydrophobic character. This derivative is characterized by the highest self-association constant (ka = 299 L mol?1) and the lowest Gibbs energy (ΔG = -14 kJ mol?1). Substituting the phenyl with pyridyl ring in the oxazole analogue enhances significantly the solubility in water and thus decreases the self-association constant. Concentration dependent 1H ROESY spectra provide information about the orientation of the molecules in the stack.
IMPROVED ENVIRONMENT SENSING CYANINE AND MEROCYANINE DYES
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Paragraph 0230; 0246, (2015/07/16)
The present invention provides dyes having improved characteristics for imaging applications, biosensors comprising such dyes, and methods of use thereof, including methods for detecting target molecules in a sample and for live-cell imaging. The biosensors can include a binding member, including a biomolecule or fragments thereof, which can interact with target molecules of interest and can be specific to a given conformational state or covalent modification of the target molecule. The presently disclosed dyes can be used for detecting changes in the binding, conformational change, or posttranslational modification of the target molecule.
Third-order nonlinear optical properties of unsymmetric pentamethine cyanine dyes possessing benzoxazolyl and benzothiazolyl groups
Sun, Ru,Yan, Bao-Long,Ge, Jian-Feng,Xu, Qing-Feng,Li, Na-Jun,Lu, Jian-Mei,Wu, Xing-Zhi,Song, Ying-Ling
, p. 189 - 195,7 (2020/08/20)
A series of unsymmetric pentamethine cyanine dyes featuring benzoxazolyl and benzothiazolyl groups were synthesized, the structures were characterized by 1H NMR, UV-vis absorption spectroscopy and mass spectrometry. The dyes with different anions such as chloride, tetraphenylborate and tetra(4-fluorophenyl)borate were also obtained and their solubility can be changed by the choice of the anion part. The third-order nonlinear optical properties were measured by the Z-scan technique with a picosecond laser beam at 532 nm in DMF solution. The third-order nonlinear optical susceptibilities χ(3) and the second-order hyperpolarizabilities γ' were obtained. The results reveal that these dyes exhibit strong reverse saturable absorption and nonlinear refraction.
A comparative study of symmetrical and unsymmetrical trimethine cyanine dyes bearing benzoxazolyl and benzothiazolyl groups
Shi, Quan-Quan,Sun, Ru,Ge, Jian-Feng,Xu, Qing-Feng,Li, Na-Jun,Lu, Jian-Mei
experimental part, p. 1506 - 1511 (2012/03/11)
Six symmetrical and unsymmetrical trimethine cyanine dyes bearing benzothiazolyl and benzoxazolyl groups were synthesized. Their linear optical properties were studied. It was found that the variation of hetero atoms play an important role in the spectral properties of the dyes. Sequential replacement of the oxygen atom by the sulfur atom resulted in a change in shade from yellow to purple. In order to understand the relationship between the molecular structures and the spectral properties of these dyes, theoretical calculations were made using the Gaussian programme. Key parameters related to absorption and emission spectra were reported and discussed.
Influence of Phenacyl Moiety as a Quaternising Group in the Absorption of Dyes derived from Nitrosoazapyrrocoline and Quaternary Heterocyclic Compounds
Sarangi, B. K.,Behera, Rajani K.
, p. 759 - 762 (2007/10/02)
The synthesis of 1-aza-3-nitroso-2-phenylpyrrocoline (1) has been described.The unusual absorption data of the dyes derived from the condensation of 1-aza-3-nitroso-2-phenylpyrrocoline and N-phenacyl-2-methyl- and N-phenacyl-2-amino-pyridine have been explained as arising out of cyclisation of product during the reaction.The influence of quaternising groups on the absorption the dyes synthesised from the nitrosoazapyrrocoline (1) has been discussed.
