A new kind of “thiophilic” electron-donor-acceptor adsorbent

Four simple agarose derivatives have been synthesized: 3-(Z-pyridylsulfido)-2-hydroxypropyl- 3-(2-pyridyloxy)-2-hydroxypropyl- 3-(phenylsulfido)-2-hydroxypropyl-, and 3-(phenyloxy)-2-hydroxypropylagarose. Their affinities for serum proteins have been studied in the presence and absence of water-structuring salt. About 50% of the proteins, among them immunoglobulins and α₂-macroglobulin, but not albumin, were non-covalently adsorbed to the PyS-gel in buffer containing 0.5 M K₂SO₄. These proteins are the same as those adsorbed to the so-called thiophilic gel, T-gel (5), but there are some additional proteins found in the adsorbate that strongly indicate a specific influence on the protein adsorption exerted by the π-electron system of the pyridine residue. The thio-ether sulfur appears to be a necessary structural requirement for the characteristic adsorption behaviour. Thiophilic vs. hydrophobic ligand-protein interaction is discussed.     

Synthesis,purification, and characterization of “perfect” star polymers via “Click” coupling

The copper (I)‐catalyzed azide‐alkyne cycloaddition “click” reaction was successfully applied to prepare well‐defined 3, 6, and 12‐arms polystyrene and polyethylene glycol stars. This study focused particularly on making “perfect” star polymers with an exact number of arms, as well as developing techniques for their purification. Various methods of characterization confirmed the star polymers high purity, and the structural uniformity of the generated star polymers. In particular, matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry revealed the quantitative transformation of the end groups on the linear polymer precursors and confirmed their quantitative coupling to the dendritic cores to yield star polymers with an exact number of arms. In addition to preparing well‐defined polystyrene and poly(ethylene glycol)homopolymer stars, this technique was also successfully applied to amphiphilic, PCL‐b‐PEG star polymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

“Superpermeability” and “pumping” of atomic hydrogen through palladium membranes

Permeation of atomic as well as molecular hydrogen through palladium membranes has been investigated experimentally in the temperature range from room temperature to 200 °C and at a higher incident flux of hydrogen atoms on palladium surface than in previous studies. The results demonstrate that phenomena of ‘superpermeability’ and ‘pumping’ of atomic gases through metal membranes are of a common nature. A theoretical model based on chemical thermodynamics and diffusion theory adequately describes the quantitative relationships observed in experiments. It was found that permeability of atomic hydrogen depends strongly on the magnitude of surface incident flux and membrane temperature.     

“Hole-burning spectra”. A new method for obtaining fine structure in absorption spectra of organic molecules

A new method is proposed for obtaining fine structure in broad-band absorption spectra of organic molecules in solid solutions at low temperature. This method is based on the laser burning of a series of narrow gaps in inhomogeneously broadened absorption spectra. A special spectral set-up has been developed for the measurement of the differential spectrum (a “hole-burning spectrum”) of “burnt” and “unburnt” samples. As an example the hole-burning spectrum of Zn-tetraphenylporphine in ethanol has been considered.