205248-60-8Relevant academic research and scientific papers
The role of the size of aza-crown recognition moiety in azaphthalocyanine fluorescence sensors for alkali and alkaline earth metal cations
Lochman, Lukas,Svec, Jan,Roh, Jaroslav,Novakova, Veronika
, p. 178 - 187 (2015)
A series of fluorescence sensors bearing one 1-aza-12-crown-4, 1-aza-15-crown-5, 1-aza-18-crown-6 or 1-aza-21-crown-7 as a recognition moiety and an aza-analogue of phthalocyanine as a fluorophore was prepared. All compounds absorbed and emitted light in the red region. Sensing properties based on intramolecular charge transfer were studied via absorption and fluorescence titration experiments with alkali metal cations and alkaline earth metal cations. Important relationships between aza-crown size and binding affinity were observed in the group of alkali metal cations. Affinity for lithium decreased in series from the smallest crown to the largest, 1-aza-15-crown-5 bound sodium and potassium similarly, and 1-aza-18-crown-6 had the highest affinity to potassium. Alkaline earth metal cations were bound more tightly, which was obvious from more pronounced changes in the absorption spectra, and from the higher increase of fluorescence upon cation addition. A limited size preference was observed in the group of alkaline earth metal cations.
Synthesis of monoazacrown ethers under phase-transfer catalysis
Luk'yanenko,Basok,Kulygina, E. Yu.,Bogashchenko, T. Yu.,Yakovenko
, p. 1345 - 1352 (2013/02/22)
A procedure has been proposed for the synthesis of monoazacrown ethers by reaction of N-benzyldiethanolamine with oligo(ethylene glycol) bis-p-toluenesulfonates in a two-phase system aromatic hydrocarbon-50% aqueous alkali, followed by removal of the benzyl group by catalytic hydrogenolysis. The maximal yields of N-benzylaza-12-crown-4, -18-crown-6, and -21-crown-7 were achieved by adding 4-10 equiv of LiCl, BaBr2, and CsCl, respectively, to the reaction mixture, which probably indicated template effect. Pleiades Publishing, Ltd., 2012.
Effect of crown ether ring size on binding and fluorescence response to saxitoxin in anthracylmethyl monoazacrown ether chemosensors
Mao, Hua,Thorne, John B.,Pharr, Jennifer S.,Gawley, Robert E.
, p. 1273 - 1279 (2007/10/03)
Convenient macrocyclization synthetic routes for the preparation of different-sized monoaza anthracylmethyl crown ether chemosensors (15-crown-5, 18-crown-6, 21-crown-7, 24-crown-8, and 27-crown-9) are described. Evaluation of these crowns as chemosensors for saxitoxin revealed that the larger crowns have moderately higher binding constants, with the 27-crown-9 chemosensor having the largest binding constant (2.29 × 105 (mol/L)-1). Fluorescence enhancements of 100% were observed at saxitoxin concentrations of 5 μmol/L, which is close to the detection limit in mouse bioassay.
