
TY  - JOUR
A1  - Crimp, SJ 
A1  - Spiccia, L 
T1  - Characterization of Three 'Active' Rhodium(III) Hydroxides
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1995
VL  - 48
IS  - 3
SP  - 557
EP  - 566
KW  - 
UR  - https://doi.org/10.1071/CH9950557 
N2  - Pure solutions of [ Rh (H2O)6]3+, dimer [Rh2(&#956;-OH)2(H2O)8]4+ and trimer [Rh3(&#956;-OH)4(H2O)10]5+ have been converted into their respective 'active' hydroxides by dropwise addition to an imidazole solution. These 'active' hydroxides have been analysed by a variety of techniques including rhodium determination, infrared spectroscopy, thermal analysis and powder X-ray diffraction. Purity determinations using ion-exchange chromatography showed that the three hydroxides consist primarily of the neutral forms of the starting aqua ion (>96%) with small amounts of species with higher nuclearity. Rhodium analysis and thermogravimetric measurements confirmed the composition of these hydroxides to be Rh (OH)3(H2O)3.H2O, Rh2(&#956;-OH)2(OH)4(H2O)4 and Rh3(&#956;-OH)4(OH)5(H2O)5.5H2O. A scheme for the thermal decomposition of each of the hydroxides has been proposed on the basis of the t.g . and d.t.a . data and the knowledge that the final product in each case is &#945;-Rh2O3. Heating of the hydroxides in air resulted in oxidation of RhIII to RhIV (temperature 250-300&#176;C) forming RhO2 which on further heating decomposed to &#945;-Rh2O3 and dioxygen. 
ER  -

