Manganese compounds structures

However, the nature of these compounds could not be determined until in 1963 Danielsen et al. made a crystal structure analysis of the manganese compound (77). Later on these dichlorophosphates, in analogy to reaction (26), were prepared from dichlorophosphoric anhydride too ... 

It seems probable that the coordinatively unsaturated species, InRe(CO)5, is involved in the synthesis of (A), and that the second species, (B), results from further condensation of (A). The structure of the analogous compound, Mn2 (CO)8 [ 2 -InMn(CO)5 ]2, is known212) and it is worth noting that this manganese compound does not undergo a further condensation, corresponding to Eq. (32). Compound (B) has a remarkable thermal stability and decomposes over 296 °C it is stable in air and also in solution108). Its structure is shown in Fig. 6. 

Four distinct types of spectra are shown in Fig. 1, all of manganese compounds. This figure shows the contrasts which may be encountered within compounds of a single element. These distinctive types of Fig. 1 recur frequently in this study. For convenience they will be referred to by type numbers. The structural correlations with these types are indicated here. 

Fio. 6. Spectra of variety of manganese compounds MnF4 has high amplitude, MnS low amplitude fine structure. 

The dimensions of the unit cells do not seem to be related to each other, so that the compounds listed apparently are not iso-structural. In contrast to this Hoppe, Liebe and Ddhne (166) assume the manganese compounds AMnFs (A = K, Rb, Cs) to be of the same type. The x-ray diagrams are similar to each other, but stiU could not be indexed. It remains to be checked, whether the unit cell given later by Clark and Sadana (66) for KMnFs may be applicable to the Rb- and Cs-compounds. 

The coordination chemistry [8] and electrochemical properties [9-11] of manganese-containing compounds have been reviewed on a number of occasions. These collections contain primarily thermodynamic and (to a lesser extent) kinetic information on compounds of relatively simple composition. The objective in this chapter is to provide a descriptive summary of the electrochemical properties of a wide range of manganese compounds. There is generous coverage of coordination complexes, which seeks to illustrate relationships between structure and... 

The selenium-selenium and tellurium-tellurium distances observed in the manganese compounds provide further evidence for this structural interpretation. They correspond to radii that agree more satisfactorily with the normal-valence radii than with the tetrahedral radii of the nonmetallic atoms, indicating that the atoms are not forming tetrahedral covalent bonds ... 

A dinuclear Mn111 porphyrin complex linked by an o-phenylene bridge (LI4) (Figure 32) [161] seems to be the first reported structurally well-defined manganese compound to oxidize H20 by a four-electron process. 

Structural features of the compounds in entries 1-6 have already been discussed in Section IV,A. The manganese compound in entry 2 (and its rhenium analog) were prepared by heating Ph2SiH2 with the metal carbonyl M2(CO)i0 similar germanium- and tin-manganese derivatives have been made via Eq. (144) (263, 414). 

The use of magnetic data as primary evidence for any structure is precluded by the variety of structural types—oligomeric and dimeric—which are known to give antiferromagnetism. In addition, manganese compounds exhibiting antiferromagnetism are now known to have metal atoms in different oxidation states and there is the further possibility of different spin states. 

Titanium and Manganese Compounds. Veillard and co-workers have published preliminary results for Ti(porph)02 and a more detailed discussion in a paper reviewing the results of their series of ab initio LCAO MO SCFcalculations Using the experimental geometry for the metal porphyrin unit in which the titaniiun atom lies out of the porphyrin plane, they find an structure to be appreciably more stable than an r) ... 

Other Manganese Compounds.—MnGa2Se and MnGa2Te have been prepared by direct synthesis from the elements at 900—1000 Structural studies on (Fe,... 

Diboranes(4) and dihaloboranes are the traditional boron source for the synthesis of homodinudear bridging borylene compounds. Reaction of K[( 5-C5H4Me)Mn(CO)2H] with a variety of B2R2CI2 derivatives afforded the homodimetallic manganese compounds [(/x-BX) ( 5-C5R5)Mn(CO)2 2] (R = NR 2, fBu) (23a,b-26a,b), which represent the first series of structurally authenticated borylene complexes (Scheme 10) [45-47]. 

The results of the XAS and EPR data, combined with knowledge from model complexes, (discussed later) allow for the formulation of structural models of the OEC. Many manganese compounds have been proposed as structural models for the OEC, ranging from butterfly arrangements to adamantanes to cubanes (26, 27,29-34, 50). Most of those proposals, however, are inconsistent with the known structural data for the OEC. Currently the most widely favored model is the dimer of dimers model (Scheme 11), first suggested by Klein,... 

---