Oxalyl-tethered pyrroles can be doubly bridged with two difluoroboron chelating units to yield bright orange dyes. Interestingly, in polar organic solvents, the addition of fluoride and cyanide result in reversible detachment of the otherwise stable difluoroboron bridges, resulting in sharp changes in color. Thus, this novel compound behaves as a highly selective chromogenic sensor for fluoride...

Solvent collisions can often mask initial disposition of energy to the products of solution-phase chemical reactions. Here, we show with transient infrared absorption spectra obtained with picosecond time resolution that the nascent HCN products of reaction of CN radicals with cyclohexane in chlorinated organic solvents exhibit preferential excitation of one quantum of the C-H stretching mode a...

A sensitive and specific assay for the simultaneous quantification of trihexyphenidyl and its hydroxylated metabolite in plasma and urine is described. The method is based on the extraction of the drugs with an organic solvent and separation on a 3% OV-17 Chromosorb Q column in a gas chromatograph equipped with a nitrogen-phosphorus detector. The procedure employs SKF 525 A as the internal stan...

A novel complex of Gram-positive antibiotics was produced from the fermentation of an actinomycete culture AB 1246E-26. The antibiotics were recovered from the whole fermentation broth by extraction with organic solvent and isolated using counter-current chromatography. UV and IR data place these compounds in the anthraquinone-derived class of antibiotics. Mass spectral and NMR data indicate a ...

ABSTRACT In order to improve efficiency, processability, and stability, two groups of novel poly(p-phenylene vinylene) (PPV) derivatives (P1-P3 and P4-P6) with hyperbranched structure and containing a nitro substituent were synthesized via a Gilch reaction in different monomer ratios. The properties of the polymers were investigated by using UV-Vis absorption, fluorescence spectroscopy, cyclic ...

The present work compares six biochemical methods for extraction of lipids from human serum. Although some organic solvents were good lipid extractors, they precipitated most of the total proteins and albumin. On the other hand, methodologies using Triton X-114 and silica were efficient for extraction of lipids, while sparing the protein fraction.

The antiparasitic activity of certain indigenous plant extracts was tested against the model bovine filarial parasite Setaria digitata. Among the plants tested, the extracts of Strebulus asper was found to be most effective. The chloroform and other phase of the organic solvents showed most activity indicating that the active compound may be a non polar substance having low molecular weight.

meso-Alkylidene (m-benzi)pentaphyrin containing exocyclic C=C double bonds at two meso-positions is synthesized and fully characterized for the first time. The single crystal X-ray crystallographic analysis shows a concave conformation with two pyrrole rings inverted. The first protonation occurs exclusively at core nitrogen. The synthesized compound displays concentration dependent chromogenic...

A simple zero-velocity method to determine the particle magnetic susceptibility by measuring the magnetophoretic velocity was proposed. The principle is that the magnetophoretic velocity of a particle in a liquid medium must be zero when the magnetic susceptibilities of the medium and the particle are equal, or the gravity force and the magnetophoretic force are balanced. By changing the medium...

Binary mixtures of organic solvents with limited miscibility are investigated by a two parameter equation which reliably describes the polarity of mixtures as a function of their composition. A relation is found between limited miscibility and critical change of solvent structure. The polarity of liquid mixtures of organic solvents has been quantitatively investigated in preceding papers I-6). ...