Dimethyl chalcogenides

Fig. 40 The structure of the radical cation from dimethyl chalcogenides.

Dihydrofolate reductases (DHFR), 48, 54, 56 Dimethyl chalcogenides, 131-133 Dimethylselenide, 131-133 Dimethyltellurides, 131-133 Diorgano diselenides, 113 Diorgano ditellurides, 113 Diorganochalcogen(IV) dihalides crystallographic structure, 80f redox reactions, 90 Diorganoselenides... 

Table 13 Ionization potentials and proton hyperfine splittings for dimethyl chalcogenides, CH3ECH3...

Fig. 39 Radical cations and dimer radical cations from dimethyl chalcogenides.

Figure 22 "C and MAS NMR spectra showing the formation of trialkylonium ions from the disproportionation of dimethyl chalcogenides on zeolite HZSM-5. (a) C spectrum of dimethyl ether adsorbed on HZSM-5 (b) C spectrum of dimethyl sulfide on HZSM-5 (c) "C spectrum of an authentic sample of trimethylsulfonium-ZSM-5 (d) C spectrum of dimethyl selenide on HZSM-5 (e) Se spectrum of dimethyl selenide and methanol on HZSM-5.

The chromatographic behaviour of condensed phosphates was found to be strongly influenced by water content and pH. The Ry of tris(dimethyl-amino)phosphine chalcogenides is generally lower than those of the trialkyl-phosphine chalcogenides but the difference is greatest for the P " compounds, and whereas the trialkylphosphines have the highest Ry values in the whole series, tris(dimethylamino)phosphine has the lowest. ... 

Copper chalcogenides can be readily deposited by CD. There is a strong affinity between Cu and S or Se metallic Cu exposed to elemental S dissolved in a solvent (e.g., dimethyl sulphoxide) will quickly turn black due to formation of cop-... 

Addition Reactions. All the metallaaromatic species kinetically stabilized by a Tbt group showed considerably high reactivity toward the reagents such as water, methanol, styrene, phenyl acetylene, mesitonitrile oxide, benzophenone, and 2,3-dimethyl-1,3-butadiene. Some of them were allowed to react with elemental chalcogen such as sulfur and selenium to give several kinds of unique cyclic chalcogenides as the cycloadducts. In Scheme 60 were summarized the reactions of the sila- and germabenzenes as the representative. 

Table 2. Chalcogenide Precursors. TU thiourea, TA thioacetamide, TC thiocarbazide, TSC thio-semicarbazide, ETU ethylthiourea, ATU allylthiourea, SU selenourea, DSU N,N dimethyl selenourea, TS thiosulfate, SES selenonilfate...

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