Abstract:
This paper presents a study regarding the interaction between Cr(NO3)3 and 1,2- propanediol, 1,3-propanediol
and 1,4-butanediol, respectively. Previous studies on the reaction between metal nitrates and diols showed that the primary
C-OH groups of diols are oxidized by NO3
-
to –COO-
. The resulted carboxylate anions coordinate to the metal ions
forming complexes that can be used as precursors for nanocrystalline metal oxides. The evolution of the redox reaction
between Cr(NO3)3 and the diols was studied by thermal analysis and by FT-IR spectrometry. The FT-IR spectra of the
obtained reaction products have confirmed the formation of carboxylate coordination compounds of Cr(III) evidenced by
υass(–COO-
) at ~1680 cm-1 and ~1560 cm-1 and υs (–COO-
) at ~ 1370 cm-1
. These compounds thermally decompose in the
range 250-300°C leading to amorphous nonstoechiometric chromium oxide (Cr2O3+x) which turns into nanocrystalline
Cr2O3 oxide above 400°C.
