Complex Carbonates of Iron(III)

The complex carbonates of iron(III) are shown to be anionic in nature. The solutions containing these complexes show a maximum absorbance at 460 nm. The complex carbonates of iron(III), viz., (i) K 6 [Fe 2 (OH) 2 (CO 3 ) 5 ] · H 2 O, — (ii) Na 2 [Fe 3 O 2 (OH) 3 (CO 3 ) 2 ], — (iii) K[Co(NH 3 ) 6 ] 2 [Fe 3 (OH) 4 (CO 3 ) 6 ], — (iv) K 5 [Co(NH 3 ) 6 ] 3 [Fe 3 (OH) 4 (CO 3 ) 6 ] 2 , — (v) K[Co(NH 3 ) 6 ][Fe 2 (OH) 4 (CO 3 ) 3 ], and (vi) NH 4 [Co(NH 3 ) 6 ][Fe 2 (OH) 4 (CO 3 ) 3 ] are isolated and studied by thermogravimetry. The infrared spectra of these compounds are recorded and probable band assignments made. Besides, the reaction between KHCO 3 and Fe(NO 3 ) 3 was studied through chemical and physicochemical methods.