Synthesis of 1,10,19,28-tetraoxa-4,7,13,16,22,25,31,34-octaazacyclohexatriacontane (L) and its complex [Cu4L(OH)4][ClO4]4·2H2O

Abstract

A 36-membered macrocycle with four ethylenediamine entities, 1,10,19,28-tetraoxa-4,7,13,16,22,25,31,34-octaazacyclohexatriacontane (L), has been synthesized and characterized by ¹H and ¹³C NMR and fast atom bombardment (FAB) mass spectra. Its complexing behaviour toward copper(II) ion was investigated spectroscopically and the macrocycle shown to incorporate four copper(II) ions in the range pH 6–9. A tetranuclear complex [Cu₄L(OH)₄][ClO₄]₄·2H₂O was obtained and characterized to be of a cubane-type Cu₄(OH)₄ core surrounded by the macrocycle, according to IR, visible, FAB and ESR spectra, cyclic voltammetry, and cryomagnetic susceptibility.