Titanocene pentasulfide

Titanocene pentasulfide
Names
	Other names titanocene pentasulfide
Identifiers
CAS Number	12116-82-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	57542900;
PubChem CID	92000650;
CompTox Dashboard (EPA)	DTXSID50746542 ;
	InChI InChI=1S/2C5H5.H2S5.Ti/c21-2-4-5-3-1;1-3-5-4-2;/h21-5H;1-2H;/q2*-1;;+4/p-2 Key: JDSOAGYVYGEMJJ-UHFFFAOYSA-L;
	SMILES [CH-]1C=CC=C1.[CH-]1C=CC=C1.S1SSSS[Ti2+]1;
Properties
Chemical formula	C10H10S5Ti
Molar mass	338.382
Appearance	red solid
Structure
Coordination geometry	Dist. tetrahedral
Related compounds
Related compounds	Zirconocene pentasulfide; Titanocene dichloride
	Except where otherwise noted, data are 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 and structure

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 Å and the S–S bond distances are of a normal range, 2.051–2.059 Å.^[3] The molecule exhibits a dynamic NMR spectrum owing to the chair–chair equilibrium of the TiS₅ ring which equivalizes the Cp signals at high temperatures.^[4]

Reactions

Cp₂TiS₅ reacts with sulfur and selenium chlorides, E_xCl₂, to afford titanocene dichloride and various S_5+x and S₅Se_x 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

^ Shaver, Alan; McCall, James M.; Marmolejo, Gabriela (1990). "Cyclometallapolysulfanes (And Selanes) of Bis(η ⁵ -Cyclopentadienyl) Titanium(IV), Zirconium(IV), Molybdenum(IV), and Tungsten(IV)". Inorganic Syntheses. Inorg. Synth. Vol. 27. pp. 59–65. doi:10.1002/9780470132586.ch11. ISBN 978-0-470-13258-6.
^ "π-Complexes of Group IVA metals with cyclopentadiene, indene, and fluorine". Bull. Soc. Chim. France. 11: 3548–64. 1966.
^ Epstein, E. F.; Bernal, I. (1970). "Pentachalcogenide dianions in transition-metal complexes: crystal structure of bis-(π-cyclopentadienyl)titanium pentasulphide". J. Chem. Soc. D. 1970 (7): 410–411. doi:10.1039/C29700000410.
^ Shaver, Alan; McCall, James M. (1984). "Preparation and Variable-Temperature NMR Studies of the Metallacyclosulfanes Cp₂MS₅ and (MeSCp)MS₃, Where M = Ti, Zr, and Hf". Organometallics. 3 (12): 1823–1829. doi:10.1021/om00090a008.
^ Steudel, Ralf; Eckert, Bodo (2003). "Solid Sulfur Allotropes Sulfur Allotropes". Topics in Current Chemistry. 230: 1–80. doi:10.1007/b12110.
^ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999). Advanced Inorganic Chemistry (6th ed.). Wiley. ISBN 978-0-471-19957-1.

[1] Shaver, Alan; McCall, James M.; Marmolejo, Gabriela (1990). "Cyclometallapolysulfanes (And Selanes) of Bis(η ⁵ -Cyclopentadienyl) Titanium(IV), Zirconium(IV), Molybdenum(IV), and Tungsten(IV)". Inorganic Syntheses. Inorg. Synth. Vol. 27. pp. 59–65. doi:10.1002/9780470132586.ch11. ISBN 978-0-470-13258-6.

[2] "π-Complexes of Group IVA metals with cyclopentadiene, indene, and fluorine". Bull. Soc. Chim. France. 11: 3548–64. 1966.

[3] Epstein, E. F.; Bernal, I. (1970). "Pentachalcogenide dianions in transition-metal complexes: crystal structure of bis-(π-cyclopentadienyl)titanium pentasulphide". J. Chem. Soc. D. 1970 (7): 410–411. doi:10.1039/C29700000410.

[4] Shaver, Alan; McCall, James M. (1984). "Preparation and Variable-Temperature NMR Studies of the Metallacyclosulfanes Cp₂MS₅ and (MeSCp)MS₃, Where M = Ti, Zr, and Hf". Organometallics. 3 (12): 1823–1829. doi:10.1021/om00090a008.

[5] Steudel, Ralf; Eckert, Bodo (2003). "Solid Sulfur Allotropes Sulfur Allotropes". Topics in Current Chemistry. 230: 1–80. doi:10.1007/b12110.

[AdvInorgChem-6] Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999). Advanced Inorganic Chemistry (6th ed.). Wiley. ISBN 978-0-471-19957-1.

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