59105-86-1Relevant articles and documents
Infrared absorbing croconaine dyes: Synthesis and metal ion binding properties
Avirah, Rekha R.,Jyothish, Kuthanapillil,Ramaiah, Danaboyina
, p. 274 - 279 (2008)
(Graph Presented) Quinaldine-based croconaine dyes synthesized by the condensation reaction between croconic acid and the respective quinaldinium salts are described. These dyes exhibit absorption maximum in the infrared region (840-870 nm) with high molar extinction coefficients (1-5 × 10 5 M-1 cm-1) and have very low fluorescence quantum yields. Upon binding to divalent metal ions, these dyes were found to form complexes with a 2:1 stoichiometry having high association constants of the order of 1011-1014 M-2, while the monovalent metal ions showed negligible affinity. The binding of the croconaine dye 3d with divalent metal ions especially Zn2+, Pb2+, and Cd 2+ led to significant chelation-enhanced fluorescence emission. The broadening of the aromatic signals, vinylic and N-methyl protons and the negligible changes at the aliphatic region of the dye 3d in the 1H NMR spectrum in the presence of Zn2+, indicate that the binding occurs at the carbonyl groups of the croconyl ring. The shift in the croconyl carbonyl stretching frequency in the [3d-Zn2+] complex analyzed through FT-IR analysis further confirms the involvement of two electron-rich carbonyl groups of the croconyl moiety in the complexation. These results demonstrate that the binding of the divalent metal ions at the carbonyl oxygens of these infrared absorbing dyes can be favorably utilized for the development of potential sensors for the detection of metal ions and further can be exploited as sensitizers for photodynamic therapeutic applications.
Synthesis, spectral properties of cell-permeant dimethine cyanine dyes and their application as fluorescent probes in living cell imaging and flow cytometry
Zhang,Liu,Shi,Wang,Fu,Wei,Yang
, p. 232 - 240 (2013/10/22)
A series of dimethine cyanine dyes, used as fluorescent probes, were synthesized under microwave irradiation, and identified by 1H NMR, IR, elemental analysis and HRMS. The investigation of their spectral properties in phosphate-buffer saline (PBS) showed that the absorption and emission maxima of the dyes were in the region 370-480 nm and 471-569 nm, respectively. The properties of the dyes as fluorescent probes for living cells imaging and flow cytometry were investigated. The results showed that dyes 1, 2, 8 or 9 could penetrate an intact cell membrane, stained the cell nuclear and exhibited bright fluorescence. Little background interference, low cell cytotoxicity and little photobleaching were showed during the imaging tests. The dyes 1, 8 and 9 could be applied in flow cytometry and dye 1/PI, dye 8/PI or dye 9/PI couple could be proposed as double staining agents to measure sperm cell viability. Thus the dyes represented the cell-permeant fluorescent probes.
