Synthesis and binding properties of amide-functionalised polyaza macrocycles
Abstract
A series of amide N-functionalised coronands has been prepared based on parent [9]-N3, [12]-N3, [12]-N2O2, and [12]-N4 polyazamacrocycles. Complexation with alkali and alkaline earth cations, particularly Li+, Na+, and Ca2+, has been monitored by using 13C NMR and IR spectroscopy, fast atom bombardment mass spectrometry, calorimetric, and potentiometric analysis in aqueous and alcoholic media. Particularly strong complexation in water has been observed for Ca2+ with 1,4,7,10-tetrakis(N,N-dimethylacetamido)-1,4,7,10-tetra-azacyclododecane, (9)(log Ks= 6.82-[H2O, 298 K]), and selective Ca2+ complexation was observed with 1,7-dioxa-4,10-bis(dimethylethanamido)-4, 10-diazacyclododecane, (7).