Laser-Induced Electron-Transfer Processes in a Pyrene–β-Cyclodextrin Complex in Titanosilicate Systems

We have used fluorescent spectroscopy and laser flash photolysis to investigate the photonics of pyrene molecules in a pyrene–-cyclodextrin inclusion complex in various media. We have observed a protective effect of -cyclodextrin relative to solubilized pyrene molecules during quenching of fluorescence by Ti ions (or titanium dioxide particles) in mixed colloids. In the presence of a precursor of silica (a TEOS solution), the pyrene molecules react with the colloidal silica particles formed, and the reaction is accompanied by decomposition of the pyrene–-cyclodextrin inclusion complex and efficient photoionization of pyrene.     

Imprinted diffractive optics for terahertz radiation

Terahertz diffractive optic elements have been fabricated in polypropylene by imprinting with a silicon master. A silicon master is created with eight phase levels for high diffraction efficiency and etched using inductively coupled plasma reactive ion etching. This technique enables the rapid replication of complex optical structures in a high transmission material. Excellent replication of multilevel high efficiency Fresnel lenses is shown. The resulting lenses were tested with a 2 THz quantum cascade laser. The signal strength at the focus was 70 times the base signal strength.     

A palladium-catalyzed multicomponent synthesis of imidazolinium salts and imidazolines from imines, acid chlorides, and carbon monoxide

A palladium-catalyzed multicomponent synthesis of imidazolinium carboxylates and imidazolines is described. The palladium catalyst [Pd(CH(R(1))N(R(2))COR(3))Cl](2), or [Pd(allyl)Cl](2), with P(t-Bu)(2)(2-biphenyl) can mediate the simultaneous coupling of two imines, acid chloride, and carbon monoxide into substituted imidazolinium carboxylates within hours under mild conditions (45 °C, 4 atm of CO). The reaction proceeds in good yield with aryl-, heteroaryl-, and alkyl-substituted acid chlorides, as well as variously functionalized imines. Imidazolines are formed via the initial generation of Mu?nchnone intermediates, followed by their cycloaddition with an in situ generated protonated imine. The addition of an amine base can intercept catalysis at Münchnone formation, which allows the subsequent cycloaddition of a second imine. The latter provides a route for the assembly of complex, polysubstituted imidazolinium carboxylates with independent control of all five substituents. The subsequent removal of the nitrogen substituent(s) provides an overall synthesis of imidazolines.     

Neutral complexes of Ga2X4 (X = Cl,Br) containing GaGa bonds: The crystal and molecular structure of Ga2Cl4 · 2Pyridine

The complexes Ga₂X₄ · 2L (L = pyridine, 3-methylpyridine, 4-methylpyridine, morpholine, 1,4-thioxane, 1,4-dithiane, tetrahydropyran, tetrahydrofuran, tetrahydrothiophene and dimethylsulphide) have been prepared. Vibrational spectra indicate that they all contain GaGa bonds and this is confirmed for Ga₂Cl₄ · 2pyridine by a crystal structure determination which shows it to be isostructural with the bromide analogue. We were unable to synthesize complexes of stoichiometry Ga₂X₄ · 4L which had previously been reported.     

New99mTc-diiodine substituted IDA derivative (DIIODIDA) for hepatobiliary imaging

A new diiodine substituted IDA derivative, 2,4-diiodine-6-methyl IDA (DIIODIDA) was synthesized and labeled with^99mTc. It was established that^99mTc-DIIODIDA had high radiochemical purity. Biodistribution and influence of bilirubin on^99mTc-DIIODIDA biokinetics has been studied in rats and compared to the corresponding results for^99mTc-SOLCOIODIDA. Related to^99mTc-SOLCOIODIDA,^99mTc-DIIODIDA has much better biliary exretion (55.18 versus 43.63%). No change of^99mTc-DIIODIDA biokinetics, under influence of bilirubin was noticed. Biliary excretion of^99mTc-SOLCOIODIDA has been reduced for about 60%. The protein binding of^99mTc-DIIODIDA and^99mTc-SOLCOIODIDA were also determined, using in vitro method of precipitation. These results showed that^99mTc-DIIODIDA hepatobiliary imaging agent is superior to the presently used^99mTc-monoiodine IDA derivatives.     

Energy and electron transfer reactions on silica gel and titania–silica mixed oxide surfaces

Research on Chemical Intermediates - The energy and electron transfer reactions of anthracene co-adsorbed with an electron donor on silica gel and titania–silica mixed oxides have been...