Room-temperature phosphorescence,sensitized phosphorescence and fluorescence of licit and illicit drugs enhanced by organized media

The ability of microscopically organized media, in the form of surfactant micelles and α- and β-cyclodextrins, to enhance the luminescence phenomena of several licit and illicit drugs is discussed. Because physiological samples are not often amenable to direct spectrometric measurements without pretreatment, the applicability of these organized media to liquid chromatography is also considered. Fluorescence enhancements for certain hallucinogenic drugs such as N,N-dimethyltryptamine, mescaline and ibogaine are seen in cyclodextrin media compared to conventional, homogeneous solutions. Heavy-atom substituted sodium dodecyl sulfate micelles induce phosphorescence from cationic and/or hydrophobic drugs at room temperature in fluid solution; drugs such as propranolol, diflunisal, naphalozine, and selected quinoline derivatives can be determined conveniently. Sensitized phosphorescence is observed for several drugs including brethine, cocaine, didrate, estradiol, meprobarbital, methaqualone, phenobarbital, and sulfanilamide; it can be enhanced markedly when micellar solutions are used as the solvent. The energy-transfer step is facilitated by the organizing ability of the micelle; limits of detection can be decreased by over two orders of magnitude compared to homogeneous solvents. Sensitized phosphorescence can also be measured in cyclodextrin solutions, but the detectability is inferior to that in micellar media. Which form of organized medium is superior for determination of drugs is discussed.     

The chiral anomaly and goldstone-wilczek current in even dimensions

The form of the non-abelian anomaly is described in arbitrary even dimension when the gauge group contains explicit U(1) factors. An effective action is constructed which when varied under the group reproduces the anomaly. It constitutes a generalization of the Wess-Zumino action.     

A Geometrical Interpretation of the Existing Facility Solution Condition for the Weber Problem

In this paper, the Weber problem is considered. We demonstrate how the three existing points may be simultaneously tested for optimality by means of a simple geometrical construction.     

Reversible PtII–CH3 deuteration without methane loss: metal–ligand cooperation vs. ligand-assisted PtII-protonation

Di(2-pyridyl)ketone dimethylplatinum(ii), (dpk)Pt^II(CH₃)₂, reacts with CD₃OD at 25 °C to undergo complete deuteration of Pt–CH₃ fragments in ∼5 h without loss of methane to form (dpk)Pt^II(CD₃)₂ in virtually quantitative yield. The deuteration can be reversed by dissolution in CH₃OH or CD₃OH. Kinetic analysis and isotope effects, together with support from density functional theory calculations indicate a metal–ligand cooperative mechanism wherein DPK enables Pt–CH₃ deuteration by allowing non-rate-limiting protonation of Pt^II by CD₃OD. In contrast, other model di(2-pyridyl) ligands enable rate-limiting protonation of Pt^II, resulting in non-rate-limiting C–H(D) reductive coupling. Owing to its electron-poor nature, following complete deuteration, DPK can be dissociated from the Pt^II-centre, furnishing [(CD₃)₂Pt^II(μ-SMe₂)]₂ as the perdeutero analogue of [(CH₃)₂Pt^II(μ-SMe₂)]₂, a commonly used Pt^II-precursor.

Di(2-pyridyl)ketone dimethylplatinum(ii), (dpk)Pt^II(CH₃)₂, reacts with CD₃OD at 25 °C to undergo complete deuteration of Pt–CH₃ fragments in ∼5 h without loss of methane to form (dpk)Pt^II(CD₃)₂ in virtually quantitative yield.     

Energy transfer and excimer formation in a flowing afterglow of Mg metastables

Mg atoms were vaporized into a fast flowing Ar carrier stream and then excited by an ac discharge. Downstream of the discharge in the afterglow region metastable Mg (³P) atoms were reacted with vaporized metals. The resultant chemiluminescence consisted of metal atom resonance lines and continuous emission bands of the molecule KMg.     

Complex geometry,unification, and quantum gravity. II. The generations problem

The new model of elementary particles as vertical vectors on the principal fiber bundleU(3, 2) U(3, 2)/U(3, 1)×U(1) introduced in Part I is extended to higher generations.     

Aspects of Take Temperature Dependence of Electrical Conductivity in Polymeric Materials

The temperature dependence of the electrical conductivity of a number of polymeric organic and inorganic materials is described by a function, G(E,T), that is the derivative of the Fermi function. The mathematical justification for the use of this function in place of the Fermi function is described. Use of the G(E,T) function in the appropriate conductivity equation allows one to reproduce the temperature dependence of electrical conductivity in materials as diverse as (SN) and germanium single crystals, The function is found to be applicable to experimental conductivity data that collectively span a range of about 20 orders of magnitude, and a total temperature range of approximately 1000 K for the materials cited. The G(E,T) function adequately simulates the commensurate-incommensurate transition that is observed in materials such as (TMTSF)₂PF₆ and TTF-TCNQ. The importance of lattice order and the degree of single crystal perfection on derived properties of the conductivity curve are discussed. The G(E,T) function is applicable to other electron transport properties. The temperature dependence of electrical capacitance of SrTiO₃ is cited as an example,     

Structural,luminescence, and NMR studies of the reversible binding of acetate,lactate, citrate,and selected amino acids to chiral diaqua ytterbium,gadolinium, and europium complexes

The nature of the ternary complexes formed in aqueous media at ambient pH on reversible binding of acetate, lactate, citrate, and selected amino acids and peptides to chiral diaqua europium, gadolinium, or ytterbium cationic complexes has been examined. Crystal structures of the chelated ytterbium acetate and lactate complexes have been defined in which the carboxylate oxygen occupies an "equatorial" site in the nine-coordinate adduct. The zwitterionic adduct of the citrate anion with [EuL1] was similar to the chelated lactate structure, with a 5-ring chelate involving the apical 3-hydroxy group and the alpha-carboxylate. Analysis of Eu and Yb emission CD spectra and lifetimes (H2O and D2O) for each ternary complex, in conjunction with 1H NMR analyses of Eu/Yb systems and 17O NMR and relaxometric studies of the Gd analogues, suggests that carbonate, oxalate, and malonate each form a chelated (q = 0) square-antiprismatic complex in which the dipolar NMR paramagnetic shift (Yb, Eu) and the emission circular polarization (gem for Eu) are primarily determined by the polarizability of the axial ligand. The ternary complexes with hydrogen phosphate, with fluoride, and with Phe, His, and Ser at pH 6 are suggested to be monoaqua systems with Eu/Gd with an apical bound water molecule. However, for the ternary complexes of simple amino acids with [YbL1]3+, the enhanced charge demand favors a chelate structure with the amine N in an apical position. Crystal structures of the Gly and Ser adducts confirm this. In peptides and proteins (e.g. albumin) containing Glu or Asp residues, the more basic side chain carboxylate may chelate to the Ln ion, displacing both waters.     

Synthesis,characterization and Hirshfeld surface analysis of a mixed-ligand copper (II) coordination polymer from 1,4,8,11-tetraazacyclotetradecane and pyromellitic dianhydride

Transition Metal Chemistry - One pot synthesis of a new mixed-ligand coordination polymer has been carried out by combining copper salt, macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane...