Titanocene pentasulfide
 | |
| Names | |
|---|---|
| Other names
titanocene pentasulfide | |
| Identifiers | |
12116-82-4  | |
| Properties | |
| C10H10S5Ti | |
| Molar mass | 338.382 |
| Appearance | red solid |
| Structure | |
| Dist. tetrahedral | |
| Related compounds | |
| Related compounds |
Zirconocene pentasulfide. titanocene dichloride |
| Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Titanocene pentasulfide is the organotitanium compound with the formula (C5H5)2TiS5, commonly abbreviated as Cp2TiS5. This metallocene exists as a bright red solid that is soluble in organic solvents. It is of academic interest as a precursor to unusual allotropes of elemental sulfur as well as some related inorganic rings.
Preparation
Titanocene pentasulfide is prepared by treating Cp2TiCl2 with polysulfide salts:[1] It was first produced by the addition of elemental sulfur to titanocene dicarbonyl:[2]
- (C5H5)2Ti(CO)2 + 5/8 S8 → (C5H5)2TiS5 + 2 CO
The complex is viewed as a pseudotetrahedral complex of Ti(IV). The Ti-S distances are 2.420 and 2.446 A and the S-S bond distances are of a normal range, between 2.051 to 2.059 Å.[3] The molecule exhibits a dynamic NMR spectrum owing the chair-chair equilibrium of the TiS5 ring which equivalences the Cp signals at high temperatures.[4]
Reactions
Cp2TiS5 reacts with sulfur and selenium chlorides, ExCl2, to afford titanocene dichloride and various S5+x and S5Sex rings. Illustrative is the synthesis of S7 from disulfur dichloride:[5]
- (C5H5)2TiS5 + S2Cl2 → (C5H5)2TiCl2 + S7
It also reacts with alkenes and ketenes to give heterocycles composed of Ti, C and S. With trialkylphosphines, the cycle dimerize into rings of various sizes, depending on the trialkylphosphine used.[6]
References
- ↑ Alan Shaver, James M. Mccall, Gabriela Marmolejo, "Cyclometallapolysulfanes (and Selanes) of Bis(η5-Cyclopentadienyl) Titanium(IV), Zirconium(IV), Molybdenum(IV), and Tungsten(IV)" Inorganic Syntheses, 1990, Vol. 27, pp. 59–65. doi:10.1002/9780470132586.ch11
- ↑ "pi-Complexes of Group IVA metals with cyclopentadiene, indene, and fluorine" Bulletin de la Societe Chimique de France 1966, vol. 11, pp. 3548-64.
- ↑ E. F. Epstein, I. Bernal "Pentachalcogenide dianions in transition-metal complexes: crystal structure of bis-(π-cyclopentadienyl)titanium pentasulphide" J. Chem. Soc. D, 1970, 410-411. doi:10.1039/C29700000410
- ↑ Alan Shaver, James M. McCall "Preparation and Variable-Temperature NMR Studies of the Metallacyclosulfanes Cp2MS5and (MeSCp),MS3, Where M = Ti, Zr, and Hf" Organometallics 1984, vol. 3, pp. 1823-1829.
- ↑ Steudel, Ralf; Eckert, Bodo (2003). "Solid Sulfur Allotropes Sulfur Allotropes". Topics in Current Chemistry 230: 1–80. doi:10.1007/b12110.
- ↑ F. Albert Cotton; Geoffrey Wilkinson; Carlos A. Murillo; Manfred Bochmann (1999). Advanced Inorganic Chemistry, 6th Edition. Wiley. ISBN 978-0471199571.