Structure cristalline de l'acide ferrocyanhydrique H₄[Fe(CN)₆]

The crystal structure of LaKFe(CN)6.4H2O

“…The Fe II ion is octahedrally coordinated to the cyanides as evidenced by the C-Fe-C angles in Table 2 and the Fe-C bond distances of 1.896 (9)/k. The Fe-C bond distance of 1.896 (9)/k is in complete agreement with that found by Pierrot, Kern & Weiss (1966) The nine-coordinate La is quite common. This coordination has been previously reported for both the trihydroxides and trihalides of the lanthanides (Schubert & Seitz, 1947;Zachariasen, 1948;Atoji & Williams, 1959;Christensen, Hazell & Nilsson, 1967;Beall, Wolcott & Milligan, 1977).…”

The square antiprismatic configuration for the octacyanotungstate(IV) ion. The crystal structure of H4W(CN)8.6H2O

“…This anion-anion contact is to be expected since the cation/anion radius ratio is much less than 0.414 (Pauling, 1960). The same effect was also observed by Pierrot, Kern & Weiss (1966) for H4Fe(CN)6 with N.-.N contacts of 2.68 /k and 2.88 A. The abovementioned van der Waals contact makes an angle of 134.4 ° with the W-C-N chains and corresponds to a van der Waals radius of 1"28 A for nitrogen.…”

Photomagnetic Switching of the Complex [Nd(dmf)4(H2O)3(μ‐CN)Fe(CN)5]⋅H2O Analyzed by Single‐Crystal X‐Ray Diffraction

“…[15] However, owing to strong back donation from the cyano ligands to iron, which makes the t 2g orbitals bonding, Fe 2+ ÀC bond lengths are generally shorter than Fe 3+ ÀC bond lengths in an {Fe(CN) 6 } entity. [16] Thus, when going from Fe 3+ to Fe 2+ the population of the t 2g orbitals will increase, and the bond lengths decrease. The present excited-state structure clearly shows a decrease in the iron-ligand bond lengths, and this makes the LMCT effect on iron a possible cause of the photomagnetic effect.…”