Binding of ureas and amides to a Cu(II) terpyridine complex in methanol

The binding of seven ureas and amides to Cu(terpy)2+ in methanol has been studied by EPR, NMR and UV–Vis spectroscopy. The association constants range from 6.5 M−1 for acetamide to 45.3 M−1 for propyleneurea and correlate with the gas phase basicity of ligands. In methanol/water mixtures the affinity drops rapidly on increase in water content to 20 vol.%, but the binding of propyleneurea is detectable with K = 4.1 M−1 even in pure aqueous medium.

Graphical abstractThe Cu(II) complex with terpyridine can bind such weak donors as neutral ureas, amides and even acetonitrile in highly competitive protic methanol solvent.Figure optionsDownload full-size imageDownload as PowerPoint slide