Thermolytic Transformation of Organometallic
Polymers Containing the Cr(CO)5Precursor into
Nanostructured Chromium Oxide
Carlos Dı´az,1,2Paola Castillo,1and Maria Luisa Valenzuela1
Thermal treatment in air of the organometallic polymerf NPðO2C12H8Þ
NPðOC6H4CH2CN ? ½CrðCOÞ5?0:13Þ2
nanometer-size metal oxide particles. Cr particles in the 35–85 nm range, mostly
54 nm, immersed in an phosphorus oxides matrix were found. ATG studies in air
suggest that the formation of the nanostructures occurs in four steps, the first
involving loss of the carbonyl groups of the Cr(CO)5fragment. The following
steps involve the oxidation of the organic matter and finally the oxidation of the
chromium to give the pyrolytic product. The use of these kinds of organometallic
polymers as precursors for a general and potential new route to materials having
metal/metal oxide nanostructures is discussed.
0:18gn(1) results in the formation of
KEY WORDS: Metallic nanoclusters; organometallic polyphosphazenes; chro-
mium nanoparticles; pyrolysis.
The development of synthetic methods that allow fine control of solid-state
structures at the atomic level is a fundamental goal in materials science. In
this context there has been significant interest in routes to nanostructured
metal and metal oxide materials . Although chemical and physical
methods for preparing these kinds of materials from solution have been
widely used, solid state methods are scarce. In particular, the methods for
1Departamento de Quı´mica, Facultad de Ciencias, Universidad de Chile, 653, Casilla,
2To whom correspondence should be addressed. E-mail: firstname.lastname@example.org
5. C. Dı´az and P. Castillo (2002). J. Inorg. Organomet. Polym. 11, 183.
6. I. M. Watson and J. A. Connors (1989). Polyhedron. 8, 1794.
7. L. M. Bronstein, E. Sh. Mirzoeva, M. V. Seregina, P. M. Valetsky, S. P. Solodovnikov, and
R. A. Register, in Gang-Moog Chow, and K. E. Gonsalves (eds.), Nanotechnology,
Molecularly Designed Materials (ACS Symposium Series 622, 1996), Ch. 6, p. 102.
8. H. Seebert, Anwendungen Der Schwing Bengsspektroskopie in Der Anorganishen Chemie
(Springer-Verlag, Berlin, 1966) (pp. 106, 107, 110).
9. (a) G. A. Carriedo, F. J. Garcia-Alonso, J. L. Garcia Alvarez, C. Diaz, and N. Yutronic
(2002). Polyhedron 21, 2587. (b) C. Dı´az, P. Castillo, G. A. Carriedo, P. Go ´ mez-Elipe, and
F. J. Garcı´a-Alonso (2002). Macromolec. Phys. Chem. 203, 1918. (c) C. Diaz, M. Barbosa,
and M. L. Valenzuela (2004). Mater. Res. Bull. 39, 9.