Titanocene pentasulfide

The Raman spectrum of the reaction product of titanocene pentasulfide and dichlorodiselane shows the presence of l,2,3-Se3Sj as the main species (sea Fig. 3). The normal coordinate treatment using a modified Urey-Bradley force field with 12 independent force constants resulted in a complete assignment of the spectrum and in a very good agreement between the observed and calculated wave numbers. The composition of the phase as determined from the HPLC data, molecular weight measurement, and selenium analysis agrees with the vibrational analysis. 

Recent developments in the chemistry of cyclic selenium sulfides have revealed that sulfur and selenium form a very complex binary system. Cyclic eight-membered molecules with the general formula Se Ss can be prepared from the molten mixtures of sulfur and selenium and also by a variety of chemical reactions. In all cases mixtures of different selenium sulfides are formed which it has not yet been possible to separate, In the reaction of titanocene pentasulfide with dichlorodiselane, however, the resulting mixture is simple enough to allow the major component to be identified as 1,2,3-86385... 

An interesting new entry into metallocene-containing dithiolato and diselenolato complexes (see also Section 16.5.2.4.3) are the reactions of titanocene pentasulfide (57) or pentaselenide (58) with activated alkynes.83 Titanocene dithiolates (59) and diselenolates (60) with X = CF3 and C02Me were obtained. The authors also performed a number of exchange reactions with the Se compound (60 X = CQ2Me). 

Preparation of a Cyclic Heptasulfane Using Titanocene Pentasulfide as Sulfur-... 

Titanocene pentasulfide (1) has been used as a transfer reagent for the S5 unit to prepare numerous inorganic homo- and heterocycles. More recently, cyclic organic polysulfanes have also been obtained from (1) by reaction with bis(sulfenyl chlorides) (equation 99). ... 

Small amounts of S7 are best prepared from titanocene pentasulfide (see the preparation of Se above) by reaction with dichlorodisulfane S2CI2 ( sulfiir-monochloride ) in CS2 at 0 °C [16] ... 

In principle, there is only one method to prepare Sg, and that is the reaction of titanocene pentasulfide with either S4CI2 [32] or S4(SCN)2 [33]. The needed dichlorotetrasulfane S4CI2 can be most conveniently prepared by carefully controlled chlorination of cyclo-Sf, in CCI4 at 20 °C [33] ... 

This reaction takes place at 0 °C in CS2 based on the starting material Se the yield of S4(SCN)2 is 27%. This product reacts in CS2 solution at 20 °C with titanocene pentasulfide to Sg in 18% isolated yield ... 

The reagents titanocene pentasulfide and sulfurylchloride are mixed at -78 °C in CS2 and the mixture is allowed to warm up to 0 °C with stirring. Yield of Siq 35%. Sio forms intense yellow crystals which slowly decompose at room temperature to Sg with partial polymerization to S. The reaction... 

The sulfur transfer reaction using titanocene pentasulfide and dichloropoly-sulfanes S Cl2 is very versatile and has made it possible to prepare Sn after the necessary S6CI2 became accessible in sufficient purity ... 

The preparation of S12 from titanocene pentasulfide and SCI2 has been described above under Preparation of Ss ... 

The oily product of this reaction still contains some Ss besides S8CI2 as well as other dichlorosulfanes from side-reactions. However, this product reacts with titanocene pentasulfide at 20 °C to a mixture of sulfur rings from which Si3 was isolated as yellow crystals in 5% yield [36] ... 

By ligand transfer a procedure optimized for the preparation of S20 uses the reaction of sulfurylchloride with titanocene pentasulfide in CS2 at 25 ° ... 

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