Selenium and Tellurium Analogues

Sulphurane analogues of telluryl compounds are also known to give telluryl-imides similarly. Simple treatment of telluryl or selenyl oxides with primary amines in CHCI3 also yields the corresponding telluryl- or selenyl-imides.  

Tamura, S. M. Bayomi, M. Tsunekawa, and M. Ikeda, Chem. Pharm. Bull., 1979, 27, 2137. 

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The structure of sodalite, Na lsSiaO Gl, a representative crystal of the framework class, is shown in Figure 13-13. It is interesting that the same framework is present in ultramarine (lapis lazuli).07 In the ultramarines sulfur complexes, Sx—, to which the blue color is attributed, are present in place of chlorine. The selenium and tellurium analogues are blood-red and yellow, respectively. 

The ions (w) resulting from loss of cyclopropane from the molecular ions were only observed for the sulfur, selenium and tellurium analogues. The alternative mode of fragmentation in which the hydrocarbon fragment (y) carries the charge provides the base peak for the tetrahydrofuran spectrum, but is only a minor feature of the spectra of the selenium and tellurium analogues. The hydrocarbon ion C4H/ (z) is a minor feature of the tetrahydrothiophene spectrum but provides the base peak of the spectra of the selenium and tellurium analogues. 

Have we found the Holy Grail Selenium and tellurium analogues of Vitamin E. 

The 1,3-diselenole and 1,3-thiaselenole ring systems as well as their benzo-fused analogues are well known and, due to their use as precursors for symmetrical and asymmetrical selenium and tellurium analogues of the tetrathiafulvalenes, there is much interest in these heterocycles mainly related to their properties as conductors. 

The selenium and tellurium analogues of 1,2-benzisothiazole can be prepared by procedures essentially similar to those used for 1,2-benzisothiazole. Thus l,2-benzisoselenazolin-3(2//)-one (103) may be prepared from the amide... 

PART I Thiophens and their Selenium and Tellurium Analogues... 

The photorearrangement of sulphur, selenium, and tellurium analogues of phenyl carboxylates has been reported in a series of papers over the past few years. Some of the reactions are reviewed in a more general account of the photochemistry of organic selenium and tellurium compounds. Typical examples of the process are seen in the reactions of thiol esters (194) and (195), and those... 

Hypervalent Sulphur Compounds and their Selenium and Tellurium Analogues.—The reaction of the trithiapentalene (682 R = Me) with trimethylsilyl or tributylstannyl radicals, which occurs at S-1, has been studied by e.s.r. spec-troscopy. The n.m.r. spectra of trithiapentalene (682 R = H) and the dioxathiapentalene (683), determined for the nematic phase, indicate that both... 

The electron transmission spectra of tellurophene and its analogs were recorded in the 0-6 eV energy range. Two resonances were identified for furan and thiophene and three were observed for selenium and tellurium analogues. The latter indicated a strong heteroatom d character <84MI 214-oi>. 

Reaction (9.556) leads to the bent anion (9.557a) which can form complexes such as (9.557b) [7-9]. Selenium and tellurium analogues of Equation 9.554 are known (e.g. (9.359) and (9.678)). 

Alternative formulae (9.558a-d) may sometimes be written for anions of this type, but (d) is perhaps most representative. Selenium and tellurium analogues are known (9.359). 

Aliphatic Organo-sulphur Compounds, Compounds with Exocyclic Sulphur Functional Groups, and their Selenium and Tellurium Analogues... 

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