Volume 60, Issue 16 pp. 9063-9070
Research Article

(Aza)Acenes Share the C2 Bridge with (Anti)Aromatic Macrocycles: Local vs. Global Delocalization Paths

Krzysztof Bartkowski

Krzysztof Bartkowski

Department of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50383 Wrocław, Poland

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Prof. Miłosz Pawlicki

Corresponding Author

Prof. Miłosz Pawlicki

Department of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50383 Wrocław, Poland

Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30387 Kraków, Poland

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First published: 06 January 2021
Citations: 19

Dedicated to Professor Lechosław Latos-Grażyński on the occasion of his 70th birthday

Graphical Abstract

Global switch for local effect: The linear fusion of (aza)acene and a redox switchable macrocycle (i.e. triphyrin(2.1.1)) gives a set of fused systems merging two π-conjugated clouds. A competition between local and global effects can be distinguished as documented in spectroscopic properties with a domination of (aza)acene diatropic current obtained after a redox switching within the macrocyclic flank.

Abstract

A strong conjugation present in fused systems plays a crucial role in tuning of the properties that would be showing a dependence on the efficiency of π-electrons coupling. The π-cloud available in the final structure can be drastically influenced by a side- or a linear fusion of unsaturated and conjugated hydrocarbons. The linear welding of naphthalene/anthracene or quinoxaline/benzo[g]quinoxaline with triphyrin(2.1.1) gives structures where the competition between local and global delocalization is distinguished. The aromatic character observed in skeletons strongly depends on the oxidation state of the macrocyclic flanking and is either extended over the whole system or kept as a composition of local currents (diatropic and paratropic) of incorporated units. The hybrid systems show the properties derived from the π-conjugations that interlace one another but also show a significant independence of (aza)acene subunits reflected in the observed spectroscopic properties.

Conflict of interest

The authors declare no conflict of interest.

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