Small Molecule and High Polymeric Phosphazenes Containing Oxypyridine Side Groups and Their Organometallic Derivatives:  Useful Precursors for Metal Nanostructured Materials

Abstract

The pyridine-containing copolymers {[NP(O 2 C 12 H 8 )] X [NP(OC 5 H 4 N) 2 ] 1 - X } n, with X = 0.7 ( 3a ) and X = 0.8 ( 3b ), and their respective organometallic derivatives of approximate formula {[NP(O 2 C 12 H 8 )] X [NP(OC 5 H 4 N·MLn) 2 ] 1 - X } n with MLn = CpFe(dppe), CpRu(PPh 2 ) 2, (n 5 -CH 3 C 5 H 4 )Mn(CO) 2, and W(CO) 5 have been prepared and characterized. As models, the simple compounds N 3 P 3 (OC 6 H 5 ) 5 OC 5 H 4 N·W(CO) 5 ( 2 ) and HOC 5 H 4 N·W(CO) 5 ( 1 ) have also been prepared and characterized. Pyrolysis of the organometallic polymers in air affords metallic nanostructured materials, which according to transmission electron microscopy (TEM), scanning electron microscopy (SEM), back-electron scattered imaging (BEI), energy-dispersive X-ray microanalysis, and micro-Raman data can be formulated as the coexistence of metal and metal oxide in the case of tungsten and as manganese phosphate salt in the case of manganese. A plausible formation mechanism is proposed, and the pyrolysis of the organometallic polyphosphazene polymer as a new and general method to obtain metallic nanostructured materials is discussed.