Calixarene-Based Copper(I) Complexes as Models for Monocopper Sites in Enzymes.

A cavity that acts as a molecular funnel is formed from calix[6]arene 1 and [Cu (NCCH ) ]PF [Eq. (a)]. An exchange of the well-protected acetonitrile ligand for other nitriles RCN is only possible with small R groups.