Chalcogen-ethers

The adducts 579 are obtained by direct (immediate) interaction (3.19) of chalcogen-ethers 578 - thioethers (Sect. 2.2.4.5), their selenium (Sec. 2.2.4.6), and tellurium (Sec. 2.2.4.7) analogues with metal salts ... 

The ligands that have been used in the preparation of metal nitride complexes are quite varied. They include halides, carbogenic groups (alkyl moiety and Cp ), pnic-togens (amine, amide, imide, phosphine, and arsine), and chalcogens (ether, alkox-ide, oxo, thioalkoxide, and selenides). Chart 1 provides a listing of the various ligands and the associated nitrido metal complexes. 

For comparison within the chalcogens, the oxidation potentials of the Ph-E-Me series 94, 95b, 96b, and 97b, where E = O, S, Se, Te, respectively, were evaluated by pulse radiolysis.Consistent with the analogous diaryl series, the values for this series indicate that the compounds are increasingly easy to oxidize, with telluride 97b most easily oxidized (0.74 V) and ether 94 least easily oxidized (1.62 V), with these values vs. NHE (Table 10). Eor a broader comparison, series of four or five para-substituted arylmethylsulfides, selenides, and tellurides, 95a-e, 96a-e, and 97a-d were prepared and their values determined in the same manner (Table 10). The same trends were observed, with the thioethers least... 

Neither diferrocenyl ether ( Fc-O-Fc ) nor diferrocenyl peroxide ( Fc-OO-Fc ) are known so far. However, the corresponding compounds of sulfur, selenium and tellurium are well characterized (see Sect. 5.8). The dichalcogenides Fc-EE-Fc (E = S, Se, Te) are easily obtained by oxidative dimerisation of either the lithium ferrocenyl chalcogenate, Fc-ELi, or the chalcogenols, Fc-EH, for which they can be used as stable precursors (Sect. 5.3.3) [91, 95]. Reaction of the dichalcogenides Fc-EE-Fc with Fc-Li is a possible route to the monochalcogenides, Fc-E-Fc, but the yields are... 

Pnictogen or chalcogen oxides, ethers or amides form O-bonded adducts with both SbCl3 and SbCls. Typical examples that have been characterized include [SbClsL] (L = PyNO, MesNO, (R0)3P0, The structure of [SbClsCDMSO)]... 

By far the most frequently used method is the deprotonation with potassium tert-butoxide, which gives the potassium salts in nearly quantitative yields. The method seems to be usable for any bis(chalcogenophosphinyl and -phosphoryl)imide and has been employed for a broad diversity of derivatives, regardless of the nature of the chalcogen.2,26,30,33,36-38,49,89,91,99 If the salts are needed for further use in reactions with metal halides to form complexes, the potassium salt can be used in situ, without isolation, e.g., with zinc(II) chloride or palladium and platinum chloro complexes.41,43 Potassium metal in THF also forms the salt K[SPh2PNPPh2S] in 82% yield, 38 but the method is not practical for preparative purposes. Potassium-crown ether complexes, [K(18-crown-6)][Q1Ph2PNPPh2Q1] with Q1 = O,92 Q1 = S,93 and Q1 = Se,98 have been prepared by direct complexation of the potassium salt with the macrocyclic ligand. 

Te donor atoms, and mixed donor derivatives where the donor types are both chalcogens. Therefore, while crown ethers themselves are excluded, mixed donor S/O, Se/O, and other macrocycles are included, whereas those containing, for example, S/N or S/P donor atoms are excluded. In addition, we have tried to present an overview of the coordination chemistry of the hetero-crown ethers toward a range of acceptors grouped under (i) d- and f-block metal ions, and (ii) p-block elements (groups 13-17), emphasizing in particular the variety of coordination modes observed. It is not our intention here to revisit work described prior to 2000 unless it is particularly relevant to more recent work. 

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