Related Experiment Video
Updated: Apr 24, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
My favorite aromatic compounds--a tribute to friedrich August Kekulé
1Institute of Organic Chemistry, Technical University Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany. h.hopf@tu-bs.de.
Abstract:
[For a discussion of this picture, please see the Editor's postscript at the end of the paper] Note from the Editor: We are all collectors. All one needs to do is explore a flea market, an antique fair or especially a weekend street market to understand the range of human collections. Tetsuo Nozoe, whom this project celebrates, collected autographs as well as the friendship of those who signed his books! What we collect doesn't necessarily have to be tangible. We all collect memories, stories, and anecdotes. We chemists are particularly privileged: we also collect molecules and reactions. In the essay that follows, Professor Henning Hopf shares with us his collection of favorite aromatic compounds. Hopf is the perfect chemist to have undertaken this sharing, for he has been active in the field of novel aromatic compounds for over four decades. Furthermore, Hopf is a deeply philosophical scientist. I very much admire his 2008 paper with Roald Hoffmann, "Learning from Molecules in Distress" published in Angewandte Chemie, a journal from the same pubilshers as The Chemical Record. As you read the paper that follows, imagine that Professor Hopf has just welcomed you to his home and is giving you a tour of his artwork. The walls are covered with works of Boekelheide, Cram, Fittig, Hückel, Kuck, Müllen, Newman, Scott, and Willstätter among others. Oh, yes, there's a Hopf or two! Enjoy your time in this very special museum. -Jeffrey I. Seeman Guest Editor University of Richmond Richmond, Virginia 23173, USA E-mail: jseeman@richmond.edu.
More Related Videos
Related Concept Videos
Aromatic Compounds: Overview
In 1825, Faraday...
Criteria for Aromaticity and the Hückel 4n + 2 Rule
For the first time, Eric Hückel, a German chemical physicist, derived a set of structural features for a compound to be classified as aromatic. This is now known as Hückel’s rule or...
Electrophilic Aromatic Substitution: Friedel–Crafts Alkylation of Benzene
Five-Membered Heterocyclic Aromatic Compounds: Overview
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group...
Frost Circles for Different Conjugated Systems

