Titanium isopropoxide

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Titanium isopropoxide
Identifiers
CAS number 546-68-9 YesY
PubChem 11026
Jmol-3D images {{#if:CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C|Image 1
Properties
Molecular formula C12H28O4Ti
Molar mass 284.215 g/mol
Appearance colorless to light-yellow liquid
Density 0.96 g/cm3
Melting point 17 °C; 63 °F; 290 K (approx.)
Boiling point 232 °C; 450 °F; 505 K
Solubility in water Reacts to form TiO2
Solubility soluble in ethanol, ether, benzene, chloroform
Refractive index (nD) 1.46
Hazards
LD50 7600 mg/kg (rat, oral)
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Titanium isopropoxide, also commonly referred to as titanium tetraisopropoxide or TTIP, is a chemical compound with the formula Ti{OCH(CH3)2}4. This alkoxide of titanium(IV) is used in organic synthesis and materials science. It is a diamagnetic tetrahedral molecule.

The structures of the titanium alkoxides are often complex. Crystalline titanium methoxide is tetrameric with the molecular formula Ti4(OCH3)16.[1] Alkoxides derived from bulkier alcohols such as isopropanol aggregate less. Titanium isopropoxide is mainly a monomer in nonpolar solvents.[2]

Preparation

It is prepared by treating titanium tetrachloride with isopropanol. Hydrogen chloride is formed as a coproduct:[2]

TiCl4 + 4 (CH3)2CHOH Ti{OCH(CH3)2}4 + 4 HCl

Properties

Titanium isopropoxide reacts with water to deposit titanium dioxide:

Ti{OCH(CH3)2}4 + 2 H2O TiO2 + 4 (CH3)2CHOH

This reaction is employed in the sol-gel synthesis of TiO2-based materials in the form of powders or thin films. Typically water is added in excess to a solution of the alkoxide in an alcohol. The composition, crystallinity and morphology of the inorganic product are determined by the presence of additives (e.g. acetic acid), the amount of water (hydrolysis ratio), and reaction conditions.[3] Titanium isopropoxide is a component of the Sharpless epoxidation, a method for the synthesis of chiral epoxides. The compound is also used as a catalyst for the preparation of certain cyclopropanes in the Kulinkovich reaction. Prochiral thioethers are oxidized enantioselectively using a catalyst derived from Ti(O-i-Pr)4.[4]

Naming

Titanium(IV) isopropoxide is a widely used item of commerce and has acquired many names in addition to those listed in the table. A sampling of the names include: titanium(IV) i-propoxide, isopropyl titanate, tetraisopropyl titanate, tetraisopropyl orthotitanate, titanium tetraisopropylate, orthotitanic acid tetraisopropyl ester, Isopropyl titanate(IV), titanic acid tetraisopropyl ester, isopropyltitanate, titanium(IV) isopropoxide, titanium tetraisopropoxide, iso-propyl titanate, titanium tetraisopropanolate, tetraisopropoxytitanium(IV), tetraisopropanolatotitanium, tetrakis(isopropoxy) titanium, tetraksi(isopropanolato) titanium, titanic acid isopropyl ester, titanic acid tetraisopropyl ester, titanium isopropoxide, titanium isopropylate, tetrakis(1-methylethoxy)titanium.

References

  1. see Wright D. A.; Williams, D. A. “The Crystal and Molecular Structure of Titanium Tetramethoxide” Acta Crystallographica 1968, Volume B24, pages 1107-1114. doi:10.1107/S0567740868003766
  2. 2.0 2.1 Bradley, D. C.; Mehrotra, R.; Rothwell, I.; Singh, A. “Alkoxo and Aryloxo Derivatives of Metals” Academic Press, San Diego, 2001. ISBN 0-12-124140-8.
  3. Hanaor, D.A.H.; Chironi, I.; Karatchevtseva, I.; Triani, G.; Sorrell, C.C. (2012). "Single and Mixed Phase TiO2 Powders Prepared by Excess Hydrolysis of Titanium Alkoxide". Advances in Applied Ceramics 111 (3): 149–158. doi:10.1179/1743676111Y.0000000059. 
  4. S. H. Zhao, O. Samuel, H. B. Kagan “Enantioelective Oxidation of a Sulfide:: (S)-(-)-Methyl p-Tolyl Sulfoxide” Organic Syntheses, Collected Volume 8, p.464 (1993).http://www.orgsyn.org/orgsyn/pdfs/CV8P0464.pdf

External links

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