Structural characterisation of a pentagonal bipyramidal macrocyclic chromium(III) complex; an explanation of a chromium-mediated ‘transient-template’ effect
Abstract
The template condensation of 6,6′-bis(hydrazino)-2,2′-bipyridines or 2,9-bis(hydrazino)-1,10-phenanthrolines with 2,6-pyridine dicarbonyl in the presence of chromium(III) chloride leads to the formation of free macrocycles rather than the expected metal complexes; the origin of this ‘transient-template’ effect is discussed and the crystal structural analysis of a chromium(III) macrocyclic complex is described.