Adaptable 2,5-bis((1,2,3-triazol-4-yl)methoxy)pyrazine ligands for the simple self-assembly of homoleptic 1D coordination polymers

The self-assembly of a new class of bis-tridentate ligands has led to the spontaneous formation of polymeric complexes with transition metal ions (M = Fe 2+ , Zn 2+ , Co 2+ , Cu 2+ , Ni 2+ , Mn 2+ ). A straightforward synthetic route to prepare a series of 2,5-bis(1,2,3-triazol-4-yl) pyrazine ( tzopz ) ligands containing two N , O , N -tridentate chelation pockets, through a double Cu( i ) catalysed azide-alkyne cycloaddition reaction of 2,5-bis((prop-2-yn-1-yloxy)methyl)pyrazine with a functionalised azido group is described. Complexes of the tzopz ligand have been investigated by UV-vis spectroscopy and single crystal X-ray crystallography. Complexes using this ligand motif consistently self-assemble into 1D zig-zag polymers, from which secondary interactions allow for the solid-state assembly of 2D sheets, providing an avenue for future functionalised materials. This work presents a class of bis-tridentate 2,5-bis((1,2,3-triazol-4-yl)methoxy)pyrazine tzopz ligands, which coordinate to 3d M 2+ ions to consistently assemble homoleptic 1D coordination polymers.