Utilisateur:Hanatabikh/Brouillon
Mixed valence salts[modifier | modifier le code]
Mixed valence, or mixed oxidation state, compounds are a unique class of compounds with an element presenting distinct oxidation states. They exhibit a broad range of fascinating physicochemical properties. They are widely used as dyes in pigments and paints due to their intense color.
History[modifier | modifier le code]
The first man-made mixed valence inorganic complex is Prussian Blue, FeIII4[FeII(CN)6]3·nH2O. This complex dates back to 1704 and found broad application as a dye.[1] After that, P. Day synthesized and studied thoroughly the century-old mixed valence species, Cs2SbCl6.[2] Since then,many other mixed valence salts saw light and were well classified.
Different metallic mixed valence salts[modifier | modifier le code]
A large variety of mixed valence ompounds have been known in literature using different metals. A brief summary of different metal-based mixed valence salts are descrived below.
Iron[modifier | modifier le code]
The mixed valence compounds of iron form by far the largest group presently known for any element.[3] Deussen[4] proved that the colorless iron fluoride, thought to be FeF3.4,5H2O, in reality was the mixed valence salt FeIIFe2IIIF8. 10H2O. Another example or iron mixed valence compounds is known as iron lazulite. It is known to have a shiny, jewel-like black color and contains FeII and FeIII in face-sharing octahedral coordination.[5]
Silver[modifier | modifier le code]
Silver can also possess different oxidation states in multinuclear complexes. Silver-based mixed valence systems are quite rare in literature. Only 20 mixed valence silver compounds are well-defined, some having both AgI/AgIII oxidation states.[6]
The first reported AgI/AgIII compound is AgO, which was better described later on by McMillan as AgIAgIIIO2 rather than AgIIO.[7] In 1966, McWhan et al. described the first molecular AgI/AgIII complexes and explored their high-temperature superconductivity behavior.[8]
Pioneering work done by Naumann et al.[9] unveiled the synthesis of [AgI][AgIII(CF3)4], which was recently crytsallized by Nebra et al.[6]
References[modifier | modifier le code]
- (en) « IV. Præparatio cærulei prussiaci ex germaniâ missa ad Johannem Woodward, M. D. Prof. Med. Gresh. R. S. S », Philosophical Transactions of the Royal Society of London, vol. 33, no 381, , p. 15–17 (ISSN 0261-0523 et 2053-9223, DOI 10.1098/rstl.1724.0005, lire en ligne, consulté le )
- (en) Peter Day, « Spectra and Constitution of Antimony(III) Antimony(V) Hexahalide Salts and Related Compounds », Inorganic Chemistry, vol. 2, no 3, , p. 452–456 (ISSN 0020-1669 et 1520-510X, DOI 10.1021/ic50007a006, lire en ligne, consulté le )
- (en) Melvin B. Robin et Peter Day, « Mixed Valence Chemistry-A Survey and Classification », dans Advances in Inorganic Chemistry and Radiochemistry, vol. 10, Academic Press, (DOI 10.1016/s0065-2792(08)60179-x, lire en ligne), p. 247–422
- Deussen, E. (1907). Eine neue quantitative Bestimmung des Fluors und über die Zusammensetzung des Eisenfluorids. Monatshefte für Chemie und verwandte Teile anderer Wissenschaften, 28, 163-172.
- L. Katz et W. N. Lipscomb, « The crystal structure of iron lazulite, a synthetic mineral related to lazulite », Acta Crystallographica, vol. 4, no 4, , p. 345–348 (ISSN 0365-110X, DOI 10.1107/S0365110X51001094, lire en ligne, consulté le )
- (en) Luca Demonti, Hana Tabikh, Nathalie Saffon‐Merceron et Noel Nebra, « Safe Entry to Ag(I)/Ag(III) Mixed Valence Salts Containing the Homoleptic Ag(III) Anion [Ag(CF 3 ) 4 ] − », European Journal of Inorganic Chemistry, , e202300042 (ISSN 1434-1948 et 1099-0682, DOI 10.1002/ejic.202300042, lire en ligne, consulté le )
- (en) J. A. McMillan, « Magnetic properties and crystalline structure of AgO », Journal of Inorganic and Nuclear Chemistry, vol. 13, no 1, , p. 28–31 (ISSN 0022-1902, DOI 10.1016/0022-1902(60)80231-X, lire en ligne, consulté le )
- (en) M. B. Robin, K. Andres, T. H. Geballe et N. A. Kuebler, « Metallic Conductivity and Superconductivity in Some Silver Clathrate Salts », Physical Review Letters, vol. 17, no 17, , p. 917–919 (ISSN 0031-9007, DOI 10.1103/PhysRevLett.17.917, lire en ligne, consulté le )
- D. N. W. Dukat,D. Naumann,Rev.Chim.Miner.1986,23, 589–60