New bis(amidine) ligands for highly luminescent copperI complex array

Molecular wires consisting of linearly arranged metal atoms that are embedded in polydentate ligand scaffolds have attracted considerable interest within in the past decade. In particular, Group 11 metal centers in multinuclear molecular frameworks are in the focus, since they facilitate closed-shell metal MI···MI (d10···d10) interactions (M = Cu, Ag, Au). The extraordinary luminescence properties of these materials result in potential applications not only for nanoelectronics, but also as powerful building blocks in organic light-emitting devices/diodes (OLEDs). Our concept is based on a series of the new polydentate bis(amidines) with a sterically protected flexible backbone. These ligands undergo with mesitylcopper a clean conversion into multinuclear homoleptic clusters that are highly luminescent. Herein, we present three new bis(amidine) ligands and a novel linear tetranuclear copperI complex