The Syntheses and Characterization of Aza Coronands and Cryptands Containing the 2,6-Pyridino And/Or the 1,8-Naphthyridino Subunits.

The syntheses of coronands and cryptands containing the 2,6-pyridino and 1,8-naphthyridino subunits have been accomplished. These macrocycles may contain only nitrogen heteroatoms while others contain both nitrogen and oxygen heteroatoms. Transition metal complexes have been formed only with the macrocycles which contain strictly nitrogen heteroatoms; no complexes have been found for the macrocycles which contain oxygen and nitrogen atoms. A diprotonated cobalt(II) tetrachloride salt was formed from the dimeric macrocycle which results from the reaction of 2,6-dichloropyridine with N,N-bis-2-hydroxyethylpiperazine. Several analogous systems have also been synthesized. A hexaaza-18-crown-6 analogue has also been synthesized by the treatment of 2,6-bis(chloromethyl)-pyridine with N,N\u27-dimethylethylenediamine. This compound was found to form octahedral complexes with either cobalt(II) or copper(II) chloride, wherein all of the coordination sites of the metal ion are occupied by a ligating atom of the macrocycle. In addition several other compounds of this type have been synthesized and their complexation properties studied. A few cryptands have been reported, accompanied by data on their complexation properties. Two main reaction pathways were utilized to acquire the desired macrocycles: (1) a one-pot nucleophilic substitution reaction where six bonds are formed in one reaction, and (2) a quaternization-demethylation sequence where in a stepwise manner the bridges are introduced into the macrocyclic framework. The demethylations were accomplished by the use of L-Selectride(\u27(REGTM)) which quantitative and selectively removes methyl groups from a quaternary ammonium salt. Some of the cryptands synthesized have exhibited unusual structural properties and the effect of these structural properties on these macrocycles complexation properties have been studied. Their spectral and physical properties have also been reported