Benzo-Crown-Ether Functionalized O-BODIPY Probes for Cations - A Selective Fluorescent Probe for Ba.

Herein, we report the synthesis and sensing characteristics of 4,4'-methoxy-substituted BODIPY fluorescent probes (O-BODIPYs) 3, 4 and 5 equipped with differently sized benzo-crown ethers (cf. Scheme 1, 3 (benzo-15-crown-5), 4 (benzo-18-crown-6) and 5 (benzo-21-crown7)). O-BODIPYs 3, 4 and 5 exhibited in comparison to their known F-BODIPY analogues 3a, 4a and 5a (cf.

Synthesis and crystal structures of three Schiff bases derived from 3-formyl-acetyl-acetone and benzyl-, -butyl- and ()-methyl-benzyl-amine.

Treatment of 3-formyl-acetyl-acetone with the amines benzyl-amine, -butyl-amine and ()-methyl-benzyl-amine led to the formation of the corresponding Schiff bases 3-[(benzyl-amino)-methyl-idene]pentane-2,4-dione, CHNO (), 3-[(-butyl-amino)-methyl-idene]pentan-2,4-dione, CHNO () and 3-{[()-benz-yl(meth-yl)amino]-methyl-idene}pentane-2,4-dione, CHNO (). The mol-ecules of all three compounds exist as enamine tautomers that contain a nearly planar amino-methyl-ene-pentane-2,4-dione core with a strong intra-molecular N-H⋯O hydrogen bridge. The group attached to the enamine N atom has no significant influence on the bond lengths and angles of the amino-methyl-ene-pentane-2,4-dione core.

Selective and pH-Independent Detection of Ba in Water by a Benzo-21-crown-7-Functionalized BODIPY.

Herein, we report on highly Ba selective fluorescence sensing in water by a fluorescent probe consisting of a benzo-21-crown-7 as a Ba binding unit (ionophore) and a tetramethylated BODIPY fluorophore as a fluorescence reporter. This fluorescent probe showed a Ba induced fluorescence enhancement (FE) by a factor of 12±1 independently of the pH value and a high Ba sensitivity with a limit of detection (LOD) of (17.2±0.

Synthesis and crystal structures of three Schiff bases derived from 3-formyl-acetyl-acetone and -, - and -amino-benzoic acid.

Treatment of 3-formyl-acetyl-acetone with the isomeric -, - and -amino-benzoic acids led to the formation of the corresponding Schiff bases, namely, 3-[(2-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , 3-[(3-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , and 3-[(4-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , all CHNO, that contain a planar amino-methyl-ene-pentane-2,4-dione core with a strong intra-molecular N-H⋯O hydrogen bridge. The carb-oxy-phenyl groups attached to the nitro-gen atom are almost coplanar to the central mol-ecular fragment. Depending on the position of the carboxyl unit, different supra-molecular structures with hydrogen-bonding networks are formed in the three title structures.