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

Organotransition metal chemistry
)--,
X
y
n~ 1 (empty)
( u -bond)
(n -bond)
11 L (filled)
rrt (empty)
1T -bond
{!- bond
Fig. 7.10 Possible bonding interactions in a metal-alkyne bond.
approximately be described as a metallacyclopropene. The resembles the
metallocyclopropane structure adopted by the corresponding complex of the
electrophilic alkene, C 2 F 4 • The square planar stereochemistry requires an
electron count of 16, making the alkyne formally a two-electron donor. Donation
into the nt orbitals must be important here.
Some platinum complexes in which the alkyne lies perpendicular to the plane
defined by P 2 PtMe ha ve been prepared as follows:
RC55CR
trans PtCL(Me)(PPh3 )2 AgPFe
244