A. Wojcicki, MONONUCLEAR TRANSITION-METAL ETA-3-PROPARGLY ALLENYL COMPLEXES - SYNTHESIS, STRUCTURE AND REACTION CHEMISTRY, New journal of chemistry, 18(1), 1994, pp. 61-68
Synthetic approaches to a new class of monomeric transition-metal eta3
-propargy/allenyl complexes are presented. X-ray crystallographic stud
ies on several such complexes show that the eta3-C3 fragment is bent a
nd that the eta3-hydrocarbyl ligand is best considered as a hybrid of
eta3-propargyl and eta3-allenyl resonance structures. H-1 and C-13 NMR
data are in accord with such a description of the bonding. Reaction c
hemistry of these complexes is characterized by the addition of nucleo
philes at the central carbon atom of the eta3-propargyl/allenyl ligand
, although addition at the metal to reduce ligand hapticity from eta3
to eta1 has also been encountered for the sterically less crowded meta
l systems.