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A theory of the luminescence lifetime of a radiation-damped classical electrical point dipole near a plane interface to a medium with different optical constants is given. The influence of the interface on the lifetime of the dipole is calculated in first approximation with the methods of molecular optics. Theoretical and experimental results for a purely dielectric interface are compared.
The relative stability of the siliconbromidechlorides is discussed on the timedependence of the dismutation reaction of SiCl3Br, on the measured appearence potentials of SiCl3, from SiCl3Br and SiCl4 respectively and on the enthalpies of the hydrolysis reactions. The relative strengths of the Si-Br-bonds of the different compounds were estimated, using SiCl4 as a standard.
The near and far UV spectra of the aminoboranes (Me2N)n B X3-n, n = 1, 2, 3, Me=CH3, X= H, Me, F, Cl, Br are presented. In most of the monoamino boranes the π→π * transitions dominate. In the di- and triamino boranes there were additionally found a Rydberg series and some single Rydberg transitions, partly preceding the π→π * band. The Rydberg assignments were settled particularly by comparing the band positions of the compounds relatively to their ionization energies.
By substitution of a halogen atom in cyclic phosphazenes by isocyanate or isothiocyanate new members of this class of compounds are synthesized. These compounds are fairly stable against hydrolysis. Reaction of the new compounds with amines yields
P3N3F5NHC(O)N(CH3)2 and P3N3F5NHC(S)N(CH3)2. With elemental chlorine P3N3F5N = CCl2 is formed. Numerous IR, NMR and mass spectra data of the new compounds are reported.
P3N3F5NHNH2 reacts with P3N3F5Br to yield the symmetric hydrazide P3N3F5-NHNHP3N3F5. Compounds of the type P3N3F5NHNHC(O)CX3 and P3N3F5NHN = CX2 are readily prepared from P3N3F5NHNH2 and carbonic acid chlorides and respectively aldehydes and ketones.
The reaction product of P3N3F5NHNH2 and CH3CH2CHO gives a dimeric derivate. Its structure was proofed by molecular weight, IR- and mass spectra.
In vorliegender Untersuchung wurde der Rißlöß zwischen der 1. und 2. fossilen Parabraunerde anhand schwächerer Bodenbildungen und eingeschalteter Abtragungsphasen zu gliedern versucht. Im jüngeren Riß herrschte starke Lößsedimentation vor, wobei es in mindestens 6 kaltfeuchten Abschnitten zur Ausbildung schwacher periglazialer Naßböden kam. Die Naßbodenserie wurde als Bruchköbeler Böden (B) bezeichnet. Im jüngsten Rißlöß ist wenige dm unter dem Eemboden als tephrochronologischer Leithorizont der Krifteler Tuff (vgl. SEMMEL 1968) eingeschaltet. Den mittleren Profilbereich im Rißlöß zeichnen feuchtere Klimaabschnitte mit starken Verschwemmungsphasen aus, die in den meisten Profilen zu erheblichen Diskordanzen geführt haben. An der Basis der wenigen kompletten Rißlöß-Profile treten vorwiegend in Hessen über der zumeist gekappten 2. fossilen Parabraunerde maximal zwei Schwarzerden auf, die von SEMMEL (1968) als Weilbacher Humuszonen bezeichnet werden. Unmittelbar über diesen Schwarzerden folgt die Ostheimer Zone, eine Fließerde aus aufgearbeitetem Solumaterial der liegenden Böden. Insgesamt zeigt die aus den Rißböden rekonstruierte Klimaabfolge — neben geringfügigen Abweichungen — überraschende Parallelen zur paläopedologisch-klimatischen Gliederung der Würmkaltzeit.