5043-06-1Relevant academic research and scientific papers
Longer-Wavelength-Absorbing, Extended Chalcogenorhodamine Dyes
Kryman, Mark W.,McCormick, Theresa M.,Detty, Michael R.
, p. 1944 - 1955 (2016)
Extended rhodamines were prepared by inserting an additional fused benzene ring into the rhodamine xanthylium core. The synthesis of "bent" dyes 4-E (E = S, Se, Te) began with regioselective lithiation of the 1-position of N,N-diisopropyl 6-dimethylamino-2-naphthamide (11b) with n-BuLi/TMEDA (≥25:1 1- vs 3-lithiation) followed by addition of a dichalcogenide electrophile. The synthesis of "linear" dyes 5-E (E = S, Se, Te) began with regioselective lithiation of the 3-position of N,N-diethyl 6-dimethylamino-2-naphthamide (11a) with lithium tetramethylpiperidide (≥50:1 3- vs 1-lithiation) followed by addition of a dichalcogenide electrophile. Dyes 4-E and 5-E have absorption maxima in the 633-700 nm range. Dyes 4-E generate singlet oxygen upon irradiation while dyes 4-S and 5-S are highly fluorescent, with quantum yields for fluorescence of 0.47 and 0.18, respectively. DFT calculations were performed on the 4-E and 5-E chromophores. For the dyes 4-E, the lowest energy excitation is due solely to the HOMO-LUMO transition. For dyes 5-E, the lowest energy excitation is a combination of two excitations, both having contributions from the HOMO to LUMO and HOMO-1 to LUMO.
Difluoroboron β-diketonate dye with intense red/near-infrared fluorescence in solutions and solid states
Liu, Nan,Chen, Peng-Zhong,Wang, Jian-Xin,Niu, Li-Ya,Yang, Qing-Zheng
, p. 1939 - 1941 (2019)
Difluoroboron β-diketonate (BF2bdk) complexes have attracted much attention due to their outstanding photophysical properties. However, BF2bdk with near-infrared fluorescence usually suffer from emission quenching in solid state due to the π–π stacking in aggregation. Herein, we report a BF2bdk dye exhibiting donor-acceptor (D-A) structure with the difluoroboron moiety acting as the electron acceptor and the aminonaphthalene as the electron donor. It processes intense molar extinction coefficient, large Stokes shift and strong fluorescence in red/NIR region in both solution and aggregations. It was used for NIR imaging in living cells.
Discovery of a sensitive, selective, and tightly binding fluorogenic substrate of bovine plasma amine oxidase
Ling, Ke-Qing,Sayre, Lawrence M.
supporting information; experimental part, p. 339 - 350 (2009/04/11)
(Chemical Equation Presented) We report a novel fluorogenic substrate of bovine plasma amine oxidase (BPAO), namely, (2-(6-(aminomethyl)naphthalen-2- yloxy)ethyl)trimethylammonium (ANETA), which displays extremely tight binding to BPAO (Km 183 ± 14 nM) and yet is metabolized fairly quickly (kcat 0.690 ± 0.010 s-1), with the aldehyde turnover product (2-(6-formylnaphthalen-2-yloxy)ethyl)trimefhylammonium serving as a real time reporting fluorophore of the enzyme activity. This allowed for the development of a fluorometric noncoupled assay that is 2 orders of magnitude more sensitive than the spectrophotometric benzylamine assay. The discovery of ANETA involved elaboration of the lead compound 6-methoxy-2-naphthalene- methaneamine by structure-based design, which recognized the ancillary cation binding site of BPAO as the most significant structural features controlling binding affinity. Structure-based design further ensured a high level of selectivity: ANETA is a good substrate of BPAO but is not a substrate of either porcine kidney diamine oxidase (pkDAO) or rat liver monoamine oxidase (MAO-B). ANETA represents the first highly sensitive, selective, and tight binding fluorogenic substrate of a copper amine oxidase that is able to respond directly to the enzyme activity in real time.
