Dibenzotetraaza crown ethers: a new family of crown ethers based on o-phenylenediamine

Sven H Hausner1, Cynthia A F Striley, Jeanette A Krause-Bauer

  • 1Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA. shhausner@ucdavis.edu

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Crown ethers are cyclic polyethers that contain multiple oxygen atoms, usually arranged in a regular pattern. The first crown ether was synthesized by Charles Pederson while working at DuPont in 1967. For this work, Pedersen was co-awarded the 1987 Nobel Prize in Chemistry. Crown ethers are named using the formula x-crown-y, where x is the total number of atoms in the ring and y is the number of ether oxygen atoms. The term 'crown' refers to the crown-like shape that these ether molecules take.
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Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
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Diazonium Group Substitution: –OH and –H

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Characteristics of the diene
Conformation
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