Halo-chalcogenates

Chalcogenides, 5 94-96 berkelium, 28 49, 53-54 lattice energies of, 1 192, 193 ligands, 45 16 Chalcogen(II) compounds binary halides, 35 274—280 complexes with Lewis bases, 35 293-295 halo-chalcogenates(ll), 35 280-288 mixed-valence compounds, 35 288-293 cationic species, 35 291-293... 

XjYs structure, type, 35 283 Halo-chalcogenates(IV), 35 246-255 degradation, 35 247-248 di-and trinuclear anions, 35 247, 249-251 hexahalochalcogenates(IV), 35 251-253 nonahalodichalcogenates(IV), 35 252-253 polymeric species, 35 254-255 in solvents, 35 247 Haloenzyme, 22 424 p-Halogen, see Parahalogen Halogenation, of hexafluoroacetone, 30 302-303... 

Pemamethylenetetra7ole, 32 206, 207 Pemanuclear anions halo-chalcogenates(ll), 35 287-288 halogenocuprate(I) and halogenoargenatate(I) ions, 37 22, 24... 

A recent investigation shows that halo-chalcogenous acids with higher nuclearity of the anion also can be prepared if the halide concen-... 

Hall effect, in graphite intercalation compounds, 23 290, 294, 307 Halo acids, chalcogens, 35 264-267 Halo-alkoxo-chalcogenates, (IV), 35 273-274... 

Fig. 25. Molecular structures of anionic halo-alkoxo-chalcogenates(IV), with bond distances (A) (a) the tetrachloromethoxoselenate(IV) ion in [(C6H5)4P+][SeCl40CHs ] (b) the trichloro(dioxo-ethylene-0,0 )tellurate(IV) ion in [(C6H6)4P+][TeCl3(0C2H40) ]...

A stabilization of the chalcogen(II) dihalides is possible by complex-ation with various electron pair donors (see Section III,D). A stabilization of the simple molecular species is also obtained if the halogens are substituted by pseudo-halogens. This situation is similar to the anionic halo- and pseudo-haloselenates(II) (Section III,B). As examples, Se(CN)2, Se(SCN)2, and Se(SeCN)2 could be prepared in crystalline form (182, 273). In Se(SCN)2 and Se(SeCN)2 the molecules are linked via secondary Se-"N bonds to form chains, with a distorted square planar coordination of 2 S(Se) and 2 N around the central Se (182). 

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