Karstedt's catalyst is an organoplatinum compound derived from divinyl-containing di

siloxane A siloxane is a functional group in organosilicon chemistry with the Si−O−Si linkage. The parent siloxanes include the oligomeric and polymeric hydrides with the formulae H(OSiH2)''n''OH and (OSiH2)n. Siloxanes also include branched compoun ...

. This

coordination complex A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

is widely used in

hydrosilylation Hydrosilylation, also called catalytic hydrosilation, describes the addition of Si-H bonds across unsaturated bonds."Hydrosilylation A Comprehensive Review on Recent Advances" B. Marciniec (ed.), Advances in Silicon Science, Springer Science, 2009 ...

catalysis. It is a colorless solid that is generally assumed to be a mixture of related Pt(0) alkene complexes. The catalyst is named after Bruce D. Karstedt, who developed it in the early 1970s while working for

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...

Applications

Carbon-silicon bonds are often generated via

of alkenes. This reaction has very important applications to industry. While it is favorable thermodynamically, hydrosilylation does not proceed in the absence of a catalyst, such as Karstedt's catalyst. The catalyst is produced by treatment of

chloroplatinic acid Chloroplatinic acid (also known as hexachloroplatinic acid) is an inorganic compound with the formula 3Osub>2 tCl6H2O)''x'' (0 ≤ ''x'' ≤ 6). A red solid, it is an important commercial source of platinum, usually as an aqueous solution. Alth ...

by the divinyltetramethyldisiloxane. The catalyst can also be used in a

reductive amination Reductive amination (also known as reductive alkylation) is a form of amination that involves the conversion of a carbonyl group to an amine via an intermediate imine. The carbonyl group is most commonly a ketone or an aldehyde. It is considered ...

reaction between a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

and an

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...

with

phenylsilane Phenylsilane, also known as silylbenzene, a colorless liquid, is one of the simplest organosilanes with the formula C6 H5 SiH3. It is structurally related to toluene, with a silyl group replacing the methyl group. Both of these compounds have ...

as the

reducing agent In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ). Examples of substances that are commonly reducing agents include the Earth meta ...

Structure and bonding

The oxidation state of the platinum is 0. Using

X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...

, the structure of Pt₂ Me₂SiCH=CH₂)₂Osub>3 has been confirmed. Each Pt(0) center is surrounded by three alkene ligands provided by three 1,1,3,3-tetramethyl-1,3-divinyldisiloxane ligands. The Pt center and six coordinated carbon atoms are approximately coplanar, as found for simpler complexes such as Pt(C₂H₄)₃.{{cite journal, last1=Hitchcock, first1=Peter B., last2=Lappert, first2=Michael F., last3=Warhurst, first3=Nicholas J. W., title=Synthesis and Structure of arac-Tris(divinyldisiloxane) diplatinum(0) Complex and its Reaction with Maleic Anhydride, journal=

Angewandte Chemie International Edition in English ''Angewandte Chemie'' (, meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker). Publishing formats include feature-length ...

, year=1991 , volume=30, issue=4, pages=438–440, doi=10.1002/anie.199104381

References

Platinum compounds Homogeneous catalysis Coordination complexes