_P.-Powell-auth.-Principles-of-Organometallic-Chemistry-Springer-Netherlands-1988

7
Organotransition metal
chemistry. Alkyl and
alkylidene derivatives.
Complexes of alkenes
and alkynes.
7.1 Alkyls and aryls
7 .1.1 Introduction
At the time when the alkyl and aryl derivatives of the Main Group elements were
being discovered and their chemistry developed, little progress was made in the
search for corresponding compounds of the transition elements. In general,
reactions of Grignard reagents with anhydrous transition metal halides yielded
mixtures of hydrocarbons and metal-containing residues from which no
organometallic compounds could be isolated. The few exceptions were thought to
be anomalies, rather than indications of a whole new area of knowledge yet tobe
explored. In 1907 Pope and Peachey in Cambridge, for example, isolated
trimethylplatinum halides, [Me 1 PtX] 4 , from the reaction of methyl Grignard
reagents with platinum(IV) halides. These air-stable, thermally robust materials
have since been shown to have the cubane structure in which the platinum
atoms attain an 18-electron configuration through triply bridging halogen
atoms.
Alkylgold(III) derivatives were studied by C.S. Gibson in the 19 30s and 1940s.
Iododimethylgold, (Me 2 Aui) 2 , is formed by the action ofmethylmagnesium iodide
on a cooled suspension of [py 2 AuCUCl in pyridine. It forms colourless crystals,
J/Me
M/Cl---Pt-Me
Me-Jt 1 Cl/
/ 1 Me
Me /
/t /
Me-Pt---Cl
Cl ;t-Me
Me 1
Me
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