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Sur les carbonates basiques de fer (III): II. Préparation, radiocristallographie et spectres IR. du (NH 4 ) 2 Fe 2 (OH) 4 (CO 3 ) 2 · H 2 O
Author(s) -
Dvořák V.,
Feitknecht W.
Publication year - 1969
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19690520217
Subject(s) - chemistry , octahedron , infrared spectroscopy , crystallography , oxygen atom , inorganic chemistry , crystal structure , molecule , organic chemistry
The obtention of the crystalline basic carbonate of iron (III) and ammonium, (NH 4 ) 2 Fe 2 (OH) 4 (CO 3 ) 2 · H 2 O, is described and its formula is established by chemical analysis and infrared spectroscopy. The powder X‐ray diagram could be indexed tetragonally leading to a body centred elementary cell with a = 12,04 ± 0,02 Å and c = 6,62 ± 0,01 Å. The infrared spectra show that in the CO 3 2−groups either one oxygen atom is linked to one iron atom or, rather, two oxygen atoms are linked to two iron atoms. The symmetry of the NH 4 +groups is lower than C 3 v. The OH‐groups are linked by hydrogen bonds of 2,75 Å. Two sorts of OH‐groups can be distinguished, with a radius of approximately 1,34 Å and 1, 48 Å, respectively. The iron atoms are octahedrally coordinated by oxygen atoms, but either the octahedra are deformed or the iron atoms are in part coordinated tetrahedrally.