Robust Benzo[g, h, i ]perylenetriimide Dye‐Sensitized Electrodes in Air‐Saturated Aqueous Buffer Solution

Highly electron deficient benzo[ghi]perylenetriimide (BPTI) chromophores were persistently anchored to a metal oxide electrode surface and reversible formation of their radical anions was shown in air‐saturated aqueous buffer solution. Our results show a very low reaction‐rate constant of BPTI^.? with O₂ (k=1.92±0.05×10^?2 s^?1). BPTI is a robust chromophore that can be used as the electron acceptor in molecule‐based artificial photosynthetic devices for direct water splitting in aqueous phase.     

Interplay of Exciton Coupling and Large‐Amplitude Motions in the Vibrational Circular Dichroism Spectrum of Dehydroquinidine

A detailed analysis of the computed structure, energies, vibrational absorption (VA) and circular dichroism (VCD) spectra of 30 low‐energy conformers of dehydroquinidine reveals the existence of families of pseudo‐conformers, the structures of which differ mostly in the orientation of a single O?H bond. The pseudo‐conformers in a family are separated by very small energy barriers (i.e., 1.0 kcal mol^?1 or smaller) and have very different VCD spectra. First, we demonstrate the unreliable character of the Boltzmann factors predicted with DFT. Then, we show that the large differences observed between the VCD spectra of the pseudo‐conformers in a family are caused by large‐amplitude motions involving the O?H bond, which trigger the appearance/disappearance of strong VCD exciton‐coupling bands in the fingerprint region. This interplay between exciton coupling and large‐amplitude‐motion phenomena demonstrates that when dealing with flexible molecules with polar bonds, vibrational averaging of VCD spectra should not be neglected. In this regard, the dehydroquinidine molecule considered here is expected to be a typical example and not the exception to the rule.     

Aufzählung der Abbildungsklassen endlichfach zusammenhängender Flächen

Ohne ZusammenfassungVgl. ein der Amsterdamer Akad. d. Wiss. am 26. Juni 1920 vorgelegtes und ein der Pariser Akad. d. Wiss. am 12. Juli 1920 vorzulegendes Referat.     

Zur Begründung der intuitionistischen Mathematik. III

Ohne Zusammenfassung     

Berichtigung

Ohne Zusammenfassung     

Die Theorie der endlichen kontinuierlichen Gruppen,unabhängig von den Axiomen von Lie

Ohne Zusammenfassung     

Classification of the (0, 2)-graphs of valency 8

We find the 302 graphs of valency 8 with the property that any two vertices have 0 or 2 common neighbours, and, in particular, the 104 semibiplanes of block size 8.