Search results for "Lene"

Study of the pentalene and heptalene molecules according to the SCF theory (Roothaan method)

1965

1988

An Efficient Method for Controlled Propylene Oxide Polymerization: The Significance of Bimetallic Activation in Aluminum Lewis Acids

2009

1980

Core‐shell nanoparticles with hyperbranched poly(arylene‐oxindole) interiors

2009

Opracowano synteze wysoce rozgalezionego poli(aryleno-oksyndolu) na drodze reakcji polimeryzacji pochodnej 5-bromoizatyny, a nastepnie modyfikacji terminalnych jednostek izatynowych. Tak przygotowany polimerowy rdzen, charakteryzujący sie stopniem rozgalezienia 100 %, byl substratem do rodnikowej polimeryzacji z przeniesieniem atomu (z ang. ATRP) w reakcji z akrylanem tert-butylu. Otrzymane kopolimery zawierające hydrofobowy rdzen i alkilowe lancuchy zakonczone wolnymi grupami karboksylowymi tworzą sferyczne nanocząstki. Przedstawiono wstepne wyniki badan dotyczących ich wlaściwości fizykochemicznych oraz potencjalnych zastosowan.

Darstellung von block- und pfropf-copolymeren des trioxane. 25. Mitt. Über polyoxymethylene

1965

Die kationische Polymerisation von Trioxan wird durch makromolekulare Verbindungen mit reaktionsfahigen COC-Gruppen wie Polyvinylacetat (PVA), Polyathylenterephthalat (PET), Poly-1,3-dioxolan oder Polyvinylbultyral (PVB) ubertragen. Dabei entstehen je nach der Art des makromolekularen Ubertragers Pfropf-Copolymere, Block-Copolymere oder vernetzte Copolymere. Die Produkte sind uberwiegend thermisch stabil. Bei der kationischen Polymerisation von Trioxan mus auch eine Ubertragung an den Acetalgruppen des Polyoxymethylens erwartet werden. Polymeric compounds with reactive COC groups such as polyvinyl acetate (PVA), polyethylene terephthalate (PET), poly-1,3-dioxolane or polyvinyl butyral (PVB)…

Transferability of ASTM/NIST alanine–polyethylene recipe at ISS

2000

Abstract Alanine–polyethylene solid state dosimeters were prepared at Istituto Superiore di Sanita (ISS) following the recipe proposed by National Institute of Standards and Technology (NIST) with the goal of testing its transferability. Dosimeters were prepared using 95% alanine and 5% polyethylene, by weight. They are rugged and of increased sensitivity, repeatability and reproducibility as respect to the ISS alanine-paraffin pellets. Reproducibility of about 1% was obtained at 10 Gy and at 3 Gy if one single pellet or a stack of five dosimeters were used, respectively.

Polyoxometalate-Based Molecular Materials.

1998

Molecule-based materials with active physical properties, in particular electrical, magnetic, and optical, are a focus of contemporary materials chemistry research. Certainly, one reason for this interest has been the realization that these materials can exhibit cooperative properties typically associated with the inorganic network solids, as for example metallic conduction or even superconductivity,1 ferromagnetism,2 and nonlinear optical properties.3 With respect to the electrical properties, many important achievements were obtained in the 1970s with the discovery of the first molecule-based metal in 1972,4 namely the π-electron donor-acceptor complex [TTF][TCNQ] (TTF ) tetrathiafulvalen…

2-hydroxyethylierung von oligo(iminoethylen)en und deren überführung in oligo-[N-(2-chloroethyl)iminoethylen]e

1981

Oligo[N-(2-chloroethyl)iminoethylene]s (8) were synthesized as potential antitumor agents like their low molecular weight analogues. It was found that oligo(iminoethylene)s (5) can be 2-hydroxyethylated with ethylene oxide and subsequently transformed into oligo[N-(2-chloroethyl)iminoethylene hydrochloride]s (14) with thionyl chloride. The stability of the free oligomers 8 was found to decrease with the number of N-2-chloroethyl groups in the molecule.

Silicon-guided rearrangement of 10-methyl-4,5-epoxydecalins. Methyl versus methylene migration

2003

The Lewis acid-promoted rearrangement of two 10-methyl-4,5-epoxydecalins bearing a trimethylsilyl (TMS) group on C-1 or C-9 has been studied. Migration of the C-9 methylene group to C-5 is the major reaction pathway when the TMS and the oxirane groups are on the same ring while methyl migration results exclusively when they are on different rings.