Dinaphthozethrene and Diindenozethrene: Synthesis, Structural Analysis, and Properties

Abstract

Zethrene-based condensed arenes dinaphthozethrene and diindenozethrene were synthesized by oxidative cyclodehydrogenation and palladium-catalyzed cyclization of 7,14-diarylzethrenes, respectively. Their structures were analyzed by X-ray crystallography. The photophysical and electrochemical properties of these compounds were investigated.

Chrysene‐Based Blue Emitters

“…With compounds 5 and 13 in hand, we further investigated the Scholl cyclodehydrogenations to obtain 14 and 15 , respectively, which, as a member of the larger PAHs might be utilized as IR emitters and/or be utilized for stimulated emission [16] . Only one synthetic approach to 14 was reported so far but separation from a naphthoindenozethrene [17] side product was only achieved in minuscule amounts by HPLC due to the low solubility, therefore a selective access is of interest. Bichrysenyl derivatives were employed by us to obtain several large PAH systems, such as graphene nanoribbons and (dibenzo)ovalenes [10a–c] .…”

Insights into the Scholl Coupling Reaction: A Key Transformation of Relevance to the Synthesis of Graphenes and Related Systems

“…This study also illustrates that, by judicious choice of activating/protecting groups, access to tetrabenzo[ a , cd , h , jk ]pyrenes is possible from readily available chrysene derivatives. The tetrabenzo[ a , cd , h , jk ]pyrene 6b is currently under investigation as a scaffold for the preparation of new materials . In this regard, we have shown, in an exploratory study, that the borylation[18c] of 6b proceeds in a regioselective manner to the mono‐ and bis‐boranes 7a and 7b , which upon Suzuki reaction enables access to the alkylated derivative 8 in 30 % isolated yield (Scheme ).…”

A Conformationally Stable Contorted Hexabenzoovalene

“…However, for the cyclodehydrogenation of 7 to HBO 1 the protocol needed to be slightly varied to ensure full cyclization at all targeted positions. Here the combination of DDQ and FeCl 3 as reactants gave compound 1 in 90 % yield . By addition of an etheric chlorohydride solution to 1 in chloroform, selective ipso ‐substitution of the centered tert ‐butyl groups by protons occurred, giving HBO 8 in 59 % yield …”