75935-37-4

Upstream product

• 10025-67-9 disulfur dichloride 
• 114860-19-4 1,4-{(Cp)2Ti}2Se₄ 
• 7782-49-2 selenium 
• 7704-34-9 sulfur 
• 10025-68-0 diselenium dichloride 

Relevant academic research and scientific papers

77Se NMR spectroscopic study of the molecular composition of sulfur-selenium melts

A series of six sulfur-selenium mixtures containing 0.4, 5, 15, 25, 35, and 45 molpercent of selenium were heated in evacuated ampoules at 430 deg C for 4 h and, keeping the material molten at 135 deg C, their natural-abundance 77Se NMR spectra were recorded.The equilibrium melt in each case was found to contain both heterocyclic SenS8-n species and polymeric material.The most abundant eight-membered selenium sulfide rings were SeS7, which was the main cyclic component in all melts studied in this work, and 1,2-Se2S6, the quantity of which increased with increasing selenium content of the melt.In addition the melts contained smaller amounts of 1,3, 1,4, and 1,5 isomers of Se2S6, 1,2,3, 1,2,4, and 1,2,5 isomers of Se3S5, 1,2,3,4, 1,2,3,5, and 1,2,5,6 isomers of Se4S4, 1,2,3,4,5-Se5S3, 1,2,3,4,5,6-Se6S2, and Se8.The relative distribution of the cyclic products as a function of the selenium content in the melt was virtually identical with that obtained earlier in the CS2 solutions of the quenched melts, implying that the extracted quenched melts actually represent the original melt composition as far as the SenS8-n species are concerned.The resonances due to the polymeric material in the melts could best be interpreted by the statistical random distribution of selenium and sulfur in the polymeric chains, the probability of occurrence of the different fragments being governed by the overall composition of the melt.As the selenium content increases, the relative amount of selenium bound in the polymer seems to increase at the expense of heterocyclic selenium sulfides.Key words: selenium sulfides; sulfur-selenium melt, 77Se NMR spectroscopy.

DINUCLEAR TITANOCENE CHALCOGENIDES AS SULFUR AND SELENIUM TRANSFER REAGENTS IN RING SYNTHESIS

The dinuclear titanocene complexes Cp4Ti2S6, Cp4Ti2S4 and Cp4Ti2Se4 have been reacted with SCl2, S2Cl2, and Se2Cl2, respectively.The reaction products are rings of type Sn (n=6...20) and six-, seven- and eight-membered rings of type SexSy, respectively, which have been characterized by HPLC, Raman and Se-NMR spectroscopy, as well as X-ray diffraction on single crystals.

Synthesis and structure of 1,4-[(RCp)2Ti]2Se4 and its application to the chalcogenospecific synthesis of 1,2,5,6-Se4S4

The synthesis of 1,4-[(RCp)2Ti]2Se4 (R = H (3a), Me (3b), i-Pr (3c) is described together with their applications to the preparation of 1,2,5,6-Se4S4 (4). The deselenization of (RCp)2TiSe5 (2a-c) with organophosphines gives 3a-c isolated as purple microcrystalline solids. The same compounds could also be prepared from the reaction of (RCp)2TiCl2 with solutions of Li2Se2. RCp labeling studies show that these Ti2Se4 compounds do not exchange their (RCp)2TiSe2 fragments. 77Se NMR studies indicate that 3c has one type of Se atom while three resonances are observed for the pentaselenide 2c. Compound 3b crystallizes in the triclinic space group C1 with a = 9.577 (2) ?, b = 15.145 (2) ?, c = 8.359 (1) ?, α = 97.08 (1)°, β = 92.02 (1)°, γ = 89.89 (1)°. A total of 1772 data were processed to a final RF = 0.0382, RwF. = 0.0444. The compound adopts a centrosymmetric chair conformation with Ti-Se and Se-Se distances of 2.55 and 2.34 ?, respectively. The reaction of 3a and 3b with CS2 solutions of S2Cl2 in a molar ratio 1:2 gave 4 in good yield. The single-crystal X-ray diffraction analysis of 4 indicates the presence of a cyclic crown conformer with the atomic positions occupied statistically by either S or Se due to rotational disorder. Raman spectra show three sets of lines assigned to bond stretching modes vSe-Se, vSe-S, and vS-S. The 77Se NMR spectrum of 4 exhibits only one line at 651.5 ppm. Upon heating, 4 undergoes two endothermic transformations assigned to polymerization to (Se2S2)n followed by melting at 112.5 °C.

77Se NMR spectroscopic characterization of selenium sulfide ring molecules SenS8-n

77Se NMR spectroscopy has been applied to the study of heterocyclic selenium sulfides SenS8-n obtained from the molten mixtures of the elements with up to 50 mol % selenium. The assignment of the spectra was based on the combined information from the spectra of the natural-abundance samples and from those of the corresponding 77Se-enriched samples. The main selenium-containing components in these mixtures were SeS7 and 1,2-Se2S6 with smaller amounts of 1,3-, 1,4-, and 1,5-isomers of Se2S6, 1,2,3-, 1,2,4-, and 1,2,5-isomers of Se3S5, 1,2,3,4-, 1,2,3,5-, 1,2,4,5-, and 1,2,5,6-isomers of Se4S4, the 1,2,3-isomer of Se5S3, and Se8. In addition, Se6, which is in equilibrium with Se8, could be observed in some samples. The most abundant species within the given isomeric series were those having all selenium atoms adjacent to each other. The trends in the chemical shifts and in the 77Se-77Se coupling constants are presented, and the composition of the phases as a function of the initial melt composition is discussed.