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Manganese Stereochemistry in the Structures of Oxygen-Containing Compounds

“…1c) are characterized by ρ = − 0.426 and -0.215. This fact is in good agreement with published data [1,2] according to which the presence of a linear dependence of type (1) with |ρ| > 0.9 is generally a criterion for the existence of a short-range order caused by strong A-X chemical interactions in the crystal structure. Detailed analysis shows that in the ånO 6 octahedra, which is the most abundant CP (1057 of the 1304 atoms), the length distribution of the Mn-O bonds depends on the manganese oxidation state.…”

“…When the Mn valence state is fixed, the R SD values increase with a decrease in the metal C.N. As previously [1,2], this fact can be attributed to the increase in the contribution of non-valence Mn/Z contacts following a decrease in the C.N. As can be seen from Table 1 The displacement of complexing atom A from the center of gravity of its VDP (D A ) is an integral parameter that characterizes quantitatively the central symmetry of the atom environment in the crystal structure.…”

“…2 that for Mn(III) the distribution is bimodal, while those for Mn(II) and Mn(IV) are unimodal. Note that a similar situation has been found for octahedral Mn II F 6 , Mn III F 6 , and Mn IV F 6 complexes [1]. In view of the published results [1], the bimodal distribution may be regarded as being due to the Jahn-Teller effect, because only Mn(III) ions have an electronically degenerate state in the octahedral ligand field.…”

“…This conclusion is confirmed by similar patterns of (r, ϕ) distributions for MnF 6 (Fig. 3 in [1]) and MnO 6 octahedra: for Mn(II) and Mn(IV), the contact curve [8] corresponding to the Mn-O bonds is shaped like a semicircle (Figs. 3a-3c), while in the case of Mn(III), it is split into two semicircles with the common center (Fig.…”

“…Within the framework of our research into the stereochemistry of 3 d metals [1,2], this study is devoted to analysis of compounds containing MnO n coordination polyhedra in the crystal structure. The primary crystal chemical information was selected from databases of inorganic [3] and coordination [4] compounds using the TOPOS program package [5].…”