Synthesis and structure of 1,4-((RCp)/sub 2/Ti)/sub 2/Se/sub 4/ and its application to the chalcogenospecific synthesis of 1,2,5,6-Se/sub 4/S/sub 4/
The synthesis of 1,4-((RCp)/sub 2/Ti)/sub 2/Se/sub 4/ R = H (3a), Me (3b), i-Pr (3c) is described together with their applications to the preparation of 1,2,5,6-Se/sub 4/S/sub 4/(4). The deselenization of (RCp)/sub 2/TiSe/sub 5/ (2a-c) with organophosphines gives 3a-c isolated as purple microcrystalline solids. The same compounds could also be prepared from the reaction of (RCp)/sub 2/TiCl/sub 2/ with solutions of Li/sub 2/se/sub 2/. RCp labeling studies show that these Ti/sub 2/Se/sub 4/ compounds do not exchange their (RCp)/sub 2/TiSe/sub 2/ fragments. /sup 77/Se NMR studies indicate that 3c has one type of Se atom while three resonances are observed for the pentaselenide 2c. Compounds 3b crystallizes in the triclinic space group C/anti 1/ with a = 9.577 (2) /angstrom/, b = 15.145 (2) /angstrom/, c = 8.359 (1) /angstrom/, /alpha/ = 97.08 (1)/degree/, /beta/ = 92.02 (1)/degree/, /gamma/ = 89.89 (1)/degree/. A total of 1772 data were processed to a final R/sub F/ = 0.0382, R/sub wF/ = 0.0444. The compound adopts a centrosymmetric chair conformation with Ti-Se and Se-Se distances of 2.55 and 2.34 /angstrom/, respectively. The reaction of 3a and 3b with CS/sub 2/ solutions of S/sub 2/Cl/sub 2/ 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 /nu//sub Se-Se/, /nu//sub Se-S/, and /nu//sub S-S/. The /sup 77/Se NMR spectrum of 4 exhibits only one line at 651.5 ppm. Upon heating, 4 undergoes two endothermic transformations assigned to polymerization to (Se/sub 2/S/sub 2/)/sub n/ followed by melting at 112.5/degree/C. 28 refs., 4 figs., 5 tabs.
- Research Organization:
- Technische Unviversitaet, Berlin (West Germany)
- OSTI ID:
- 5826284
- Journal Information:
- Inorg. Chem.; (United States), Vol. 27:15
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKANES
SYNTHESIS
AROMATICS
SELENIUM SULFIDES
TITANIUM COMPLEXES
EXPERIMENTAL DATA
MOLECULAR STRUCTURE
CHALCOGENIDES
COMPLEXES
DATA
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
SELENIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400202 - Isotope Effects
Isotope Exchange
& Isotope Separation