Tributyltin hydride

  • TBT
  • Tributylstannane
  • Tributyltin

Colorless to yellowish liquid

Liquid

1.10 g · cm -3 ( 20 ° C)

<0 ° C

112-114 ° C ( 11 hPa)

5 hPa (20 ° C)

In water decomposition

Risk

0.004 ml · m-3

127 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Tributyltin (TBT) is a metal- organic compound of tin. It is a colorless, toxic liquid.

  • 2.1 See also

Use

Synthetic application

The Sn -H bond in the TBT is quite weak with 310 kJ / mol, so that it can be split easily homolytically.

AIBN ( azobisisobutyronitrile ) as a free-radical initiator is used in the TBT of the Barton -McCombie reaction and the Barton decarboxylation. These two discovered by the British Nobel laureate Derek HR Barton reactions allow the reaction of alcohols or halides to their corresponding alkanes.

Another interesting reaction is the dehalogenation of halogenated alkanes, which are also often is synthetic utility in conjunction with a subsequent intramolecular radical cyclization of the alkyl radical is formed.

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

Other Applications

TBT has been used for decades as an additive in antifouling paints. The toxic substance prevented that mussels and algae on the hull lay down (fouling ). Since 2008, TBT is banned by the International Maritime Organization in marine paints.

Through the food chain TBT can enter the human or animal body where they can cause hormonal imbalances that can lead to infertility. In marine areas of high shipping volume reproduction incompetent Imposexe caused by the TBT paints the ship with numerous animal species, i.e. females external genitalia of males formed. These forms make up to 90 % of a population from the effects are irreversible and the affected species threatened by extinction in part. Due to the intervention of this environmental chemical in the hormonal balance, it is a so-called endocrine disruptor.

TBT is also used as a stabilizer in plastics and in the printing industry and can therefore also occur in printed textiles, outdoor jackets and the output to 2002 10 - euro notes.

Term " TBT "

The term TBT and TBT is used in different ways. It is an " overloaded " name:

  • As a matter In water, or seawater form as a function of pH and anions from various TBT compounds: TBT -Cl ( chloride ), TBT -OH ( - Multicore ), TBT - OH2 ( stannyl cation ) and TBT CO3 - ( carbonate). The TBT stands for the n- Bu3Sn cation.
  • As a chemical ( commodity ) different compounds with the (second) term TBT are provided. Most / often, but not always, is bis (tributyltin ) oxide ( TBTO ) and tributyltin hydride.
  • The radical n- BuTributylzinnhydrid Sn ( · ), which plays a role in the above- mentioned Barton -McCombie reaction.
CAS registry number PubChem Vapor pressure Dangerous Substances Directive (67/548/EEC) Derek Barton Stille reaction Hormone Stabilizer (chemistry) Tributyltin oxide
783734
de