Berechnung der Aktivierungsenergien für die thermische cis-trans-Isomerisierung substituierter Stilbene, Stilbazole und Stilbazolium-Salze

Die Aktivierungsenergien der thermischen cis-trans-Isome- risierung substituierter Stilbene, Stilbazole und Stilbazolium-Salze werden mittels der HMO-Methode berechnet und mit den expe- rimentellen Werten verglichen. Die Ergebnisse werden im Zusam- menhang mit dem Mechanismus der thermischen cis-trans-Isomerisierung diskutiert

Dietrich Schulte-Frohlinde (1924 – 2015)

Professor Dietrich Schulte-Frohlinde, a distinguished German chemist with long-time relationships to Croatian scientists (e.g. S. Ašperger, M. Randić, J. N. Herak, A. Graovac, I. Kraljić), and this Journal, passed away on Oct 1st, 2015 in Chevy Chase MD, USA. He was born on Dec 17th, 1924 in Munich ... This work is licensed under a Creative Commons Attribution 4.0 International License

Foreword

This issue of Croatica Chemica Acta is dedicated to Chemical Kinetics and Reaction Mechanisms on the occasion of the 80th birthday of Smiljko Ašperger

Atmosphere/soil exchange processes of importance for molecular soil sciences

Globally the atmosphere/soil exchange can be interpreted as part of the biogeochemical cycles describing the transport of main chemical elements and their gaseous compounds between the compartments of the geosphere. Approaches to monitor and analyze these transport processes are described. The paramount role of Earth’s life, the biosphere, in these processes is emphasized

Photoelectron Spectroscopy of Some trans-2,2-Disubstituted Stilbenes

The He I photoelectron (PE) spectra of stilbene (1), 2,2\u27-dichlorostilbene (2) 2-amino-2\u27-chlorostilbene (3), 2,2\u27-diaminostilbene (4) ,and 2,2\u27-dinitrostilbene (5), all in their trans configuration are recorded and discussed. The electronic structure of 1-5 can well be described on the basis of the composite molecule method and simple Hiickel molecular orbital (HMO) calculations. Results indicate the importance of substituent effects causing characteristic shifts of low energy electronic band systems in the PE spectra

Deuterium Labeling Study of the Gas-phase Reaction of Fe+/Cr+ with Pyrene by FTMS

A ~ 10 :1 mixture of deuterated with undeuterated pyrene was used to study the product composition in the reaction with various ratios of Fe+ and Cr+ (10 :1 to 1: 10) ions in a Fourier-transform mass spectrometer. None of the products FePy+, CrPy+, Py+, FePy2+, CrPy2+ and Py2+ showed deviation from the statistically expected composition