Hexaazacyclotetradecine compounds containing azo groups

The properties of non-innocent ligands (redox-activity) for the open-chain and macrocyclic ligand products have not been revealed yet, but the research is only in its infancy. Employment of redox-active metal ions as templates should create conditions for displaying this special behaviour. 

Another important reaction involved in the synthesis of macrocyclic compounds is the nucleophilic displacement of halide as the leaving group in the ring-closure step. For most systems considered here, the nucleophile is a nitrogen donor, which might be coordinated to a metal ion. 

Synthesis of 5,12- or 1,8-dihydro [1, 2, 5, 8, 9, 12] hexaazacyclotetradecine compounds, in which a macrocyclic backbone is formed by aromatic or heterocyclic 

At the end of this section the synthesis of related systems is discussed. The most frequently encountered final stage in these macrocycle template syntheses is the formation of single C-N bonds. 

The above-mentioned synthetic schemes for synthesis of hexaazacyclotetradecines can be successfully realised, if the reactions are controlled by the presence of suitable metal ions acting as templates. Thus, o-halide-o -aminoazo compounds of the L93 type (Eq. 2.56 like LlOl, L103, L105 below) do not self-condense to give macrocycles in the absence of metal salts [132, 133]. 

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