Avoiding cross-linking in iron-polyphosphazene metallo-polymers

Abstract Two new polyphosphazene ligands containing 1,10-phenanthrolin-2-olate ( L 1 ) and 2,2ʹ-bipyridine-6-olate moieties ( L 2 ) with 5,5ʹ-di-tert-butylbiphenyl-2,2ʹ-bis(olate) co-substituents were synthesised and then reacted with Fe(Pyridine) 4 (NCS) 2 . Variable temperature Mossbauer and electronic absorbance spectroscopies were used to establish the physical behaviour of the new iron-polyphosphazenes. By attaching two bidentate ligands to a geminal phosphorus atom a pseudo tetradentate ligand can be formed that prevents cross-linking when iron is coordinated to the polyphosphazene.