Search results for "Lene"
showing 10 items of 4480 documents
Massenspektrometrische Untersuchungen an Edukten für die Synthese H2-aktiver Substanzen
1982
Unter den Bedingungen der Elektronenstosionisation wurden 4-[(2-Aminoethoxy)-methyl]-5-methyl-imidazo (1), die Imidazolderivate mit N-substituierter Ethylendiamin-Struktur 2–5 sowie die Imidazolcarboxamide 6–8 massenspektrometrisch untersucht. Der Mechanismus der konkurrierenden Bindungsspaltungen und der Umlagerungsprozesse wird formuliert. Die Wechselwirkung der funktionellen Gruppen sowie deren Einflus auf das Fragmentationsverhalten der Substanzen wird beschrieben und ein Schema der Hauptfragmentierungswege vorgeschlagen. Mess Spectrometry of Reactants for the Synthesis of H2-Active Compounds 4-[(2-Aminoethoxy)methyl]-5-methylimidazole (l), the imidazoles 2-5 with N-substituted ethylene…
Stufenweise darstellung eines cycloheptamers aus p-kresol, 4-tert-butylphenol und formaldehyd. Vergleich mit einem phenolischen, heptanuklearen kette…
1980
A phenolic cycloheptamer (11) and an analogous chain oligomer (10) with nearly the same structure were gained by stepwise syntheses. The cycloheptamer has a higher melting point and a better solubility in chloroform. In contrast to the chain oligomer his infrared spectrum indicates a stronger association of the hydroxyl groups which is not influenced by the solvent. The mass spectra announce a preferred statistical cleavage along the chain of compound 10 and a great stability of the ring of 11 which preferentially loses his substituents. The 1H NMR spectra confirm the constitutions of the chain (10) and ring compound (11). The cycloheptamer is distinguished by a ring inversion or a pseudoro…
Darstellung und eigenschaften von linearen oligourethanen mit phenylendgruppen und von cyclischen oligourethanen aus diäthylenglykol und hexamethylen…
1971
Es wurden lineare Oligourethane mit Phenylendgruppen und cyclische Oligourethane aus Diathylenglykol und Hexamethylendiisocyanat dargestellt. Der groste bisher isolierte Ring enthalt je sieben Grundbausteine und besitzt 119 Ringglieder bei einem Molekulargewicht von 1920. Eine gute Trennung der Oligomeren wurde durch Adsorptionssaulenchromatographie erzielt. Hierbei wurde ein Elutionsmittel mit Losungsmittelgradient verwendet. Schmelzpunkte, Umwandlungserscheinungen, Langperioden und Weitwinkeldiagramme der Oligomeren werden im Hinblick auf ihre Struktur diskutiert. Linear oligourethanes with phenylurethane endgroups and cyclic oligourethanes were prepared from diethylene glycol and hexamet…
1983
Water soluble polyamides with iminoethylene and oxyethylene units in the main chain were obtained by condensation polymerization of diethylenetriamine and triethylenetetramine with suitable dimethylesters containing two or three oxyethylene units. The molecular weights were in the range of Mn = 5000–7000. By potentiometric and conductometric titration only 80–85% of the expected amount of basic groups was found which was probably caused by branching. Durch Polykondensation von Diethylentriamin und Triethylentetramin mit Dimethylestern von Sauren, die zwei oder drei Oxyethyleneinheiten enthalten, wurden wasserlosliche Polyamide mit Iminoethylen- und Oxyethyleneinheiten in der Hauptkette erha…
On the electron affinity of TCNQ
2004
The electron affinity of 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) has been studied with density functional theory and coupled cluster (CC) procedures. The adiabatic electron affinity of TCNQ calculated with the B3LYP method is about 1 eV higher than the available experimental value. At the CCSD(T) level, the theoretical result is overestimated by more than 0.4 eV. The electron affinity computed for TCNQ is larger than that obtained for tetracyanoethylene at all levels of calculation, exactly the opposite of what is observed experimentally. Accordingly, a call for an additional empirical measurement of such a property is made.
Cation-induced self-assembly of an amphiphilic perylene diimide derivative in solution and Langmuir–Blodgett films
2015
Abstract A novel amphiphilic perylenetetracarboxylic diimide (PDI) derivative, N-(4′-benzo-15-crown-5-ether)-N-hexyl-1,7-di(4-tert-butyl-phenoxy)perylen-3,4,9,10-tetracarboxylic diimide (15C5PDI), has been synthesized and characterized. Dimerization of 15C5PDI is induced in CHCl 3 solution with the present of K + , resulting in the formation of the slipped co-facial J -aggregates, as revealed by absorption and fluorescence spectroscopies. Analysis of the surface pressure–area ( π – A ) isotherms and spectral change for the monolayer formed at the air/water interface, disclosed that 15C5PDI molecules adopted the H -type aggregation mode with a face-to-face configuration and edge-on orientati…
Feinstrukturanalyse eines diskotischen Polymers durch Elektronenbeugung und hochauflösende Elektronenmikroskopie
1989
Concave Tetrathiafulvalene-Type Donors as Supramolecular Partners for Fullerenes
2007
The cap fits! A new class of concave π-extended tetrathiafulvalene (TTF) derivatives, truxene-TTFs, were prepared and characterized, and their self-assembly with fullerenes was investigated (see picture). Truxene-TTFs represent the first example of TTF-related electron donors that serve, without chemical modification, as monotopic receptors for fullerenes in solution. (Chemical Equation Presented). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.