Clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and Tourette syndrome. The quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. Therefore, the aim of this study was to establish the conditions for two spectroph...

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of gatifloxacin (GT) in bulk and pharmaceutical dosage form. These methods are based on the formation of yellow ion-pair complexes between the basic nitrogen of the drug and three sulphonphthalein acid dyes, namely; bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB) and bromothym...

Native electrospray ionization-mass spectrometry, with gas-phase activation and solution compositions that partially release subcomplexes, can elucidate topologies of macromolecular assemblies. That so much complexity can be preserved in gas-phase assemblies is remarkable, although a long-standing conundrum has been the differences between their gas- and solution-phase decompositions. Collision...

Although the role of methanesulfonic acid (HMSA) in particle formation in the gas phase has been extensively studied, the details of the HMSA-induced ion pair particle formation at the air-water interface are yet to be examined. In this work, we have performed Born-Oppenheimer molecular dynamics simulations and density functional theory calculations to investigate the ion pair particle formatio...

Ab initio MP2/aug'-cc-pVTZ calculations have been carried out to investigate the structures, binding energies, and bonding characteristics of binary complexes HFBe:FCl, R2Be:FCl, and FCl:N-base, and of ternary complexes HFBe:FCl:N-base and R2Be:FCl:N-base for R = H, F, Cl; N-base = NH3, NHCH2, NCH. Dramatic synergistic cooperative effects have been found between the Be···F beryllium bonds and t...

The complexation reactions between N,N'-3,6-dioxa-1,8-octanebis (salicylaldimine) [saldioxen(I)] and Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) were studied spectrophotometrically in methanol solution at 25 °C. The stoichiometry of the complexes were obtained as 2:1 and 1:1 sadioxen-metal ion using mole ratio method. The formation constants of the complexes were determined, a...

an ultrasound-assisted surfactant-enhanced emulsification microextra- ction (uaseme) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of thiopental in serum and urine samples. a simple microextraction method based on emulsification of organic extraction solvent in aqueous sample using an ionic surfactant and withou...

We present an experimental method, which provides information on the steric and electronic properties of ligands in metal complexes. This approach is based equilibrium ion-pairing a cationic [(NHC)Ir(cod)]+ fluorescent bodipy-sulfonate (bdpSO3?). The close ion-pair [(NHC)Ir(bdpSO3)(cod)] toluene solution weakly fluorescent, but dissociates into solvent-separated ion pairs upon exposure to sligh...