A new, highly fluorescent terpyridine which responds to zinc ions with a large red-shift in emission

A sequence of three metal-catalysed aryl coupling reactions leads to the new ligand 4'-(4-N,N-diphenylaminophenyl) 2,2':6',2-terpyridine, the intense ICT emission of which undergoes a large red-shift upon binding of zinc ions, providing a unique response over other common metal ions.