Fluorescent anion sensor derived from cholic acid: the use of flexible side chain

[structure: see text] The fluorescent photoinduced electron transfer (PET) chemosensors 1-3 were synthesized from cholic acid. 1 and 2 containing amidothiourea groups as anion receptive sites demonstrated much higher affinity toward anions than 3 containing traditional thiourea H-bond donating group. Comparative studies on their binding affinity toward carboxylates, dihydrogen phosphate, and halides revealed that the amidothiourea moiety on the C17 side chain could work cooperatively with H-bond donating groups on C7 and C12 to bind spherical halogen anions. An unexpected specific fluorescence enhancement of 1 by coordinating bromide ion was observed.     

A novel chiral terpyridine macrocycle as a fluorescent sensor for enantioselective recognition of amino acid derivatives

Terpyridine macrocycle 1 is shown to be a strong chelating agent for organic ammonium salts and also a useful chromophore in fluorescent sensing. It exhibits very good enantioselectivity (K(obs)(S)/K(obs)(R)= 3.8) in chiral discrimination of alpha-phenylglycine methyl ester hydrochloride (PhEtOMe).     

A New Robust Class of Skew Elliptical Distributions

Methodology and Computing in Applied Probability - A new robust class of multivariate skew distributions is introduced. Practical aspects such as parameter estimation method of the proposed class...