Extremely selective "turn-on" fluorescence detection of hypochlorite confirmed by proof-of-principle neurological studies via esterase action in living cells.

Highly specific and sensitive fluorescence detection of hypochlorite in nonbiotic pure water (rapid "turn-on", ~400 fold, λ(em) ~ 560 nm) as well as in living neuronal cell cultures (neutral pH) involves oxidation of a 2-sulfide-2-benzoic acid pendent group in a new meso-thienyl-BODIPY donor-acceptor probe.

Synthetic, 119Sn NMR spectroscopic, electrochemical, and reactivity study of organotin A3 corrolates including chiral and ferrocenyl derivatives.

Various R/Ar-functionalized tin 5,10,15-tris(pentafluorophenyl)corrolate derivatives are reported herein including the first ferrocenyltin corrolate species. The isopropyl, sec-butyl-, 2-methyl-n-butyl-, phenyl-, 2-thienyl-, and ferrocenyltin species have been prepared and characterized through (1)H, (13)C, and (119)Sn HMQC NMR spectroscopy, mass spectrometry, UV-vis and photoluminescent spectroscopy, and cyclic voltammetry studies. J(C/H-Sn) NMR spectroscopic couplings and ring-current effects (upfield shifting) were determined for the R-Sn axial hydrogen and carbon atoms. This report adds to older conceptually similar reports, by, i.e., Janson et al. (J. Am. Chem. Soc. 1969, 91, 5210) and Walker et al. (J. Am. Chem. Soc.1983, 105, 6923-6929), as discussed herein. Such NMR spectroscopic aspects are discussed for these model systems. Compound Sn-Ph bond cleavage was achieved by treatment with I(2).

Novel reversible Zn2+-assisted biological phosphate "turn-on" probing through stable aryl-hydrazone salicylaldimine conjugation that attenuates ligand hydrolysis.

A novel reversible zinc(II) chemosensing ensemble (2·Zn(2+)) allows for selective "turn-on" fluorescence sensing of ATP and PPi in aqueous media (detection limits: 2.4 and 1.0 µM, respectively) giving selective binding patterns: ATP ∼ PPi > ADP ≫ AMP > monophosphates ≈ remaining ions tested. The conjugated hydrazone [C═N-NH-R] resists hydrolysis considerably, compared to the imine [C═N-CH2-R, pyridin-2-ylmethanamine] functionality, and generalizes to other chemosensing efforts. Prerequisite Zn(2+)·[O(phenol)N(imine)N(pyr)] binding is selective, as determined by UV-vis and NMR spectroscopy; ATP or PPi extracts Zn(2+) to regenerate the ligand-fluorophore conjugate (PPi: turn-on, 512 nm; detection limit, 1.0 µM). Crystallography, 2-D NMR spectroscopy, and DFT determinations (B3LYP/631g*) support the nature of compound 2. 2-Hydrazinyl-pyridine-salicylaldehyde conjugation is unknown, as such; a paucity of chemosensing-Zn(2+) binding reports underscores the novelty of this modifiable dual cation/anion detection platform. A combined theoretical and experimental approach reported here allows us to determine both the potential uniqueness as well as drawbacks of this novel conjugation.

Synthetic, cyclic voltammetric, structural, EPR, and UV-Vis spectroscopic studies of thienyl-containing meso-A(2)B-cor(Cr(V)=O) systems: consideration of three interrelated molecular detection modalities.

We report eight new A(2)B-type (M(n+)) corrolate compounds (two structural studies) that include the oxo[5,15-bis(pentafluorophenyl)-10-R-corrolatochromium(V)] [R = 2-/3-thienyl (1a/2a), 3-thianaphthyl (3a)] species. The first examples of meso-A(2) (thienyl)- and Cr-A(2)B-corrole types are represented herein. Characterization includes cyclic voltammetry, electron paramagnetic resonance, 2D ((1)H and (13)C) NMR, and UV-vis spectroscopy, mass spectrometry, and elemental analysis. Compounds 1a-3a have enabled analyte binding capacity studies. [Cu(2+)...O=Cr(cor)] binding represents a new selective mode of corrole-based detection, whereas free-base A(2)B-corroles exhibited limited M(n+) selectivity. The 10-position substitution affects optical profiles in analyte titrations. A limited amount of PPh(3) O-atom uptake from [O=Cr(cor)] was also demonstrated.

A chiral meso-ABC-corrolatochromium(V) complex.

A chiral metallocorrole complex, oxo[5-(4-bromophenyl)-10-(pentafluorophenyl)-15-(2-thianaphthyl)corrolato]chromium(V) (7), was prepared and serves as the first example of an ABC-metallocorrole; meso substituents are of different electron-withdrawing capacity. An adaptation of a multistep protocol (D. T. Gryko) was made, followed by an aerobic oxidation using Cr(CO)(6) (Z. Gross). The X-ray crystal structure reveals the two enantiomers of 7. Electron paramagnetic resonance spectroscopy (g(iso) = 1.99) and cyclic voltammetry of 7 provide comparative data to that of the A(3)[tris(pfp)cCr(V)O] complex.

Novel and selective detection of Tabun mimics.

Detection of nerve agent-related molecules based on BODIPY-salicylaldehyde oxime conjugation was studied. Fluorescence intensity of the B-SAL-OXIME species increases in the presence of DECP, whereas it decreases in the presence of DCP and DEMP (limit of detection = 997 nM). Benzonitrile formation in the novel fluorescent B-SAL-OXIME system was elucidated using model substrates.