Terpyridine and 2,6-di(1H-pyrazol-1-yl)pyridine substituted cyclotri- and polyphosphazene ruthenium(II) complexes: Chemical and physical behaviour

The synthesis of a series of cyclotriphosphazene and polyphosphazene ruthenium(II) compounds is reported using 2,2′:6′,2″-terpyridine (terpy) and 2,6-di(1H-pyrazol-1-yl)pyridine (bpp) pendant ligands. X-ray crystallography, UV-Vis and resonance Raman spectroscopy have been employed to gain an insight into the physical and coordination behaviour of these complexes and indicate that both the small molecule and their polymeric analogues contain coordinated Ru in an octahedral 'N₆' environment. The results reveal a difference between the chemistry of the ruthenium(II)-bpp-terpy and ruthenium(II)-bis-terpy complexes and demonstrate a means of grafting functional groups to a polyphosphazene backbone under mild conditions.