Tributyltin hydride

Structural formula
General
Surname	Tributyltin hydride
other names	TBTH Tri- n -butyltin hydride Tributyl stannane Tributyl tin Bu 3 SnH
Molecular formula	C 12 H 28 Sn
Brief description	colorless to yellowish liquid
External identifiers / databases
CAS number 688-73-3 EC number 211-704-4 ECHA InfoCard 100.010.642 PubChem 5948 ChemSpider 5734 Wikidata Q425241
properties
Molar mass	291.04 g mol −1
Physical state	liquid
density	1.10 g cm −3 (20 ° C)
Melting point	<0 ° C
boiling point	112–114 ° C (11 hPa)
Vapor pressure	5 h Pa (20 ° C)
solubility	decomposes in water
Refractive index	1.4715 (25 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 301-312-315-319-360FD-372-410 P: 273-302 + 352-305 + 351 + 338-309 + 310
MAK	0.004 ml m −3
Toxicological data	127 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Tributyltin hydride ( TBTH ) is an organometallic compound of tin and a tributyltin compound .

Extraction and presentation

The compound can be obtained by reacting tributyltin chloride with sodium borohydride in a nitrogen atmosphere:

${\displaystyle {\ce {2 (C4H9)3SnCl + 2 NaBH4 -> 2 (C4H9)3SnH + B2H6 + 2 NaCl}}}$

properties

Tributyltin hydride is a colorless, toxic liquid. The Sn – H bond in TBTH is quite weak at 310 kJ / mol, so that it can easily be cleaved homolytically .

use

Synthetic application

With azobis (isobutyronitrile) (AIBN) as the radical starter , TBTH is used in the Barton-McCombie reaction and Barton decarboxylation . These two reactions, discovered by the English Nobel Prize winner Derek HR Barton , enable the conversion of alcohols and acid halides into their corresponding alkanes .

Another interesting reaction is the reductive dehalogenation of haloalkanes , which is also often synthetically useful in connection with a subsequent intramolecular radical cyclization of the alkyl radical formed.

TBTH is also often used for the synthesis of the tin organyls required for the Stille coupling .

proof

Organotin hydrides such as TBTH can be easily identified in the infrared spectrum by a pronounced Sn-H band in the range from 1800 to 1880 cm ⁻¹ .

literature

• Heinz Rüdel, Jürgen Steinhanses, Josef Müller, Christa Schröter-Kermani: Retrospective monitoring of organotin compounds in biological samples from the North and Baltic Seas - are the application restrictions successful? Environmental sciences and pollutant research 21 (3), 2009, pp. 282–291, doi : 10.1007 / s12302-009-0039-3 .

Individual evidence

1. ↑ Entry on tributyltin hydride. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.
2. ↑ ^{a b c d e f g} Data sheet tributyltin hydride for synthesis (PDF) from Merck , accessed on January 19, 2011.
3. ↑ ^{a b c} Ernest R. Birnbaum and Paul H. Javora: Organotin hydrides - A. Tri- n -butyltin hydride . In: Robert W. Parry (Ed.): Inorganic Syntheses . tape 12 . McGraw-Hill Book Company, Inc., 1970, ISBN   07-048517-8  ( defective ) , p. 45-57 (English).
4. ↑ ^{a b} Entry on tributylstannane in the GESTIS substance database of the IFA , accessed on April 24, 2011(JavaScript required) .
5. ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry tributyltin compounds, unless specifically listed in this appendix in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on January 9, 2017. Manufacturers or distributors can extend the harmonized classification and labeling .