Titanium butoxide

Titanium butoxide
	; gas phase structure
Names
	IUPAC name Titanium(IV) butoxide
	Other names Titanium(IV) butoxide, titanium n-butoxide, titanium tetrakis(butoxide), butyl titanate, tetrabutoxy titanium, titanium tetrabutoxide, tetrabutoxytitanium, tetrabutyltitanate, tetrabutyl orthotitanate, titanium tetrabutanolate, TYZOR TBT
Identifiers
CAS Number	5593-70-4;
3D model (JSmol)	Interactive image;
ChemSpider	13836735;
ECHA InfoCard	100.024.552
EC Number	227-006-8;
PubChem CID	21801;
UNII	FJS8Q2MX9I;
UN number	2920
CompTox Dashboard (EPA)	DTXSID6041262 ;
	InChI InChI=1S/4C4H9O.Ti/c41-2-3-4-5;/h42-4H2,1H3;/q4*-1;+4 Key: YHWCPXVTRSHPNY-UHFFFAOYSA-N;
	SMILES CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-].[Ti+4];
Properties
Chemical formula	C16H36O4Ti
Molar mass	340.32164
Appearance	COLORLESS TO LIGHT-YELLOW LIQUID
Odor	weak alcohol-like
Density	0.998 g/cm3
Melting point	-55 °C
Boiling point	312 °C
Solubility in water	decomposes
Solubility	most organic solvents except ketones
Refractive index (nD)	1.486
Thermochemistry
Heat capacity (C)	711 J/(mol·K)
Std enthalpy of; formation (ΔfH⦵298)	-1670 kJ/mol
Hazards
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	3122 mg/kg (rat, oral) and 180 mg/kg (mouse, intravenal).
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Titanium butoxide is a metal alkoxide with the formula Ti(OBu)₄ (Bu = –CH₂CH₂CH₂CH₃). It is a colorless odorless liquid although aged samples can appear yellowish. Owing to hydrolysis, samples have a weak alcohol-like odor. It is soluble in many organic solvents.^[1]^[3] Decomposition in water is not hazardous, and therefore titanium butoxide is often used as a liquid source of titanium dioxide, which allows deposition of TiO₂ coatings of various shapes and sizes down to the nanoscale.^[4]^[5]

Titanium butoxide is often used to prepare titanium oxide materials and catalysts.^[6]^[7]^{[citation needed]}

Structure and synthesis

Structure of a typical titanium alkoxide, e.g. titanium ethoxide (organic substituents removed for clarity).

Like most titanium alkoxides (exception: titanium isopropoxide), Ti(OBu)₄ is not a monomer but exists as a cluster (see titanium ethoxide). Nonetheless it is often depicted as a simple monomer.^{[citation needed]}

It is produced by treating titanium tetrachloride with butanol:

TiCl₄ + 4 HOBu → Ti(OBu)₄ + 4 HCl

The reaction requires base to proceed to completion.^{[citation needed]}

Reactions

Like other titanium alkoxides, titanium butoxide exchanges alkoxide groups:

Ti(OBu)₄ + HOR → Ti(OBu)₃(OR) + HOBu

Ti(OBu)₃(OR) + HOR → Ti(OBu)₂(OR)₂ + HOBu

etc. For this reason, titanium butoxide is not compatible with alcohol solvents.

Analogous to the alkoxide exchange, titanium butoxide hydrolyzes readily. The reaction details are complex, but the overall process can be summarized with this balanced equation.

Ti(OBu)₄ + 2 H₂O → TiO₂ + 4 HOBu

Diverse oxo-alkoxo intermediates have been trapped and characterized.^[8] Pyrolysis also affords the dioxide:

Ti(OBu)₄ → TiO₂ + 2 Bu₂O

Titanium butoxide reacts with alkylcyclosiloxanes. With ocatamethylcyclotetrasiloxane it produces dibutoxydimethylsilane, 1,5-dibutoxyhexamethyltrisiloxane, 1,7-dibutoxyoctamethyltetrasiloxane, 1,3-dibutoxytetramethyldisiloxane and polymers. With hexamethylcyclotrisiloxane it also produces dibutoxydimethylsilane.^[9]

Safety

LD50 is 3122 mg/kg (rat, oral) and 180 mg/kg (mouse, intravenal).^{[citation needed]}

Titanium butoxide is a corrosive, flammable liquid which reacts violently with oxidizing materials. It is incompatible with sulfuric and nitric acids, inorganic hydroxides and peroxides, bases, amines, amides, isocyanates and boranes. It is irritating to skin and eyes, and causes nausea and vomiting if swallowed. LD50 is 3122 mg/kg (rat, oral) and 180 mg/kg (mouse, intravenal); flash point is 77 °C. When heated it emits irritating fumes, which form explosive mixtures with air at concentrations above 2 vol%.^{[citation needed]}

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Butyl titanate. pubchem.ncbi.nlm.nih.gov
^ ^a ^b ^c Tetrabutyl titanate. nist.gov
^ Pohanish, Richard P.; Greene, Stanley A. (2009). Wiley Guide to Chemical Incompatibilities. John Wiley & Sons. p. 1010. ISBN 978-0-470-52330-8.
^ ^a ^b Wang, Cui (2015). "Hard-templating of chiral TiO₂ nanofibres with electron transition-based optical activity". Science and Technology of Advanced Materials. 16 (5): 054206. Bibcode:2015STAdM..16e4206W. doi:10.1088/1468-6996/16/5/054206. PMC 5070021. PMID 27877835.
^ Wu, Limin; Baghdachi, Jamil (2015). Functional Polymer Coatings: Principles, Methods, and Applications. Wiley. p. 10. ISBN 978-1-118-88303-7.
^ Qin, Qing; Zhao, Yun; Schmallegger, Max; Heil, Tobias; Schmidt, Johannes; Walczak, Ralf; Gescheidt-Demner, Georg; Jiao, Haijun; Oschatz, Martin (2019). "Enhanced Electrocatalytic N₂ Reduction via Partial Anion Substitution in Titanium Oxide–Carbon Composites". Angewandte Chemie International Edition. 58 (37): 13101–13106. doi:10.1002/anie.201906056. hdl:21.11116/0000-0004-023B-8. PMID 31257671. S2CID 195760017.
^ Xiang, Quanjun; Yu, Jiaguo; Jaroniec, Mietek (2012). "Synergetic Effect of MoS₂ and Graphene as Cocatalysts for Enhanced Photocatalytic H₂ Production Activity of TiO₂ Nanoparticles". Journal of the American Chemical Society. 134 (15): 6575–6578. doi:10.1021/ja302846n. PMID 22458309.
^ Weymann-Schildknetch, Sandrine; Henry, Marc (2001). "Mechanistic Aspects of the Hydrolysis and Condensation of Titanium Alkoxides Complexed by Tripodal Ligands". Journal of the Chemical Society, Dalton Transactions (16): 2425–2428. doi:10.1039/b103398k.
^ K. A. Andrianov; Sh. V. Pichkhadze; V. V. Komarova; Ts. N. Vardosanidze (1962). "Reactions of organocyclosiloxanes with tetrabutyl orthotitanate". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 11 (5): 776–779. doi:10.1007/BF00905301. ISSN 0568-5230.

[r1-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Butyl titanate. pubchem.ncbi.nlm.nih.gov

[r2-2] Tetrabutyl titanate. nist.gov

[r3-3] Pohanish, Richard P.; Greene, Stanley A. (2009). Wiley Guide to Chemical Incompatibilities. John Wiley & Sons. p. 1010. ISBN 978-0-470-52330-8.

[chiral-4] Wang, Cui (2015). "Hard-templating of chiral TiO₂ nanofibres with electron transition-based optical activity". Science and Technology of Advanced Materials. 16 (5): 054206. Bibcode:2015STAdM..16e4206W. doi:10.1088/1468-6996/16/5/054206. PMC 5070021. PMID 27877835.

[r4-5] Wu, Limin; Baghdachi, Jamil (2015). Functional Polymer Coatings: Principles, Methods, and Applications. Wiley. p. 10. ISBN 978-1-118-88303-7.

[6] Qin, Qing; Zhao, Yun; Schmallegger, Max; Heil, Tobias; Schmidt, Johannes; Walczak, Ralf; Gescheidt-Demner, Georg; Jiao, Haijun; Oschatz, Martin (2019). "Enhanced Electrocatalytic N₂ Reduction via Partial Anion Substitution in Titanium Oxide–Carbon Composites". Angewandte Chemie International Edition. 58 (37): 13101–13106. doi:10.1002/anie.201906056. hdl:21.11116/0000-0004-023B-8. PMID 31257671. S2CID 195760017.

[7] Xiang, Quanjun; Yu, Jiaguo; Jaroniec, Mietek (2012). "Synergetic Effect of MoS₂ and Graphene as Cocatalysts for Enhanced Photocatalytic H₂ Production Activity of TiO₂ Nanoparticles". Journal of the American Chemical Society. 134 (15): 6575–6578. doi:10.1021/ja302846n. PMID 22458309.

[8] Weymann-Schildknetch, Sandrine; Henry, Marc (2001). "Mechanistic Aspects of the Hydrolysis and Condensation of Titanium Alkoxides Complexed by Tripodal Ligands". Journal of the Chemical Society, Dalton Transactions (16): 2425–2428. doi:10.1039/b103398k.

[9] K. A. Andrianov; Sh. V. Pichkhadze; V. V. Komarova; Ts. N. Vardosanidze (1962). "Reactions of organocyclosiloxanes with tetrabutyl orthotitanate". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 11 (5): 776–779. doi:10.1007/BF00905301. ISSN 0568-5230.

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