Novel ruthenium(0) monodentate amine (primary, secondary, and tertiary) and
pyridine complexes, [Ru(eta(6)-cot)(eta(2)-dmfm)(L)] (cot=cycloocta-1,3,5-
triene, dmfm=dimethyl fumarate; L=propylamine, benzylamine, dimethylamine,
morpholine or pyridine), were prepared by the reaction of [Ru(eta(6)-cot)(e
ta(2)-dmfm)(2)] with the corresponding amine in high yields. The structures
of three of the complexes were determined by X-ray analyses and the co-ord
ination geometry around the central ruthenium atom is a highly distorted tr
igonal bipyramid. The nitrogen atom and one carbon-carbon double bond of th
e cyclooctatriene occupy the two axial positions, and the other two olefini
c bonds of the cyclooctatriene and dimethyl fumarate the equatorial positio
ns. The propylamine complex is in equilibrium with [Ru(eta(4)-cot)(eta(2)-d
mfm)(PrNH2)(2)] in the presence of an excess of propylamine. The structure
of this complex was confirmed by X-ray analysis. The position of the second
amine is equatorial and the cyclooctatriene co-ordinated in a 1-2:5-6-eta
bonding mode. When it was dissolved in CD2Cl2, propylamine at the equatoria
l position was dissociated, changing the eta(4)-cyclooctatriene to the eta(
6) mode to give [Ru(eta(6)-cot)(eta(2)-dmfm)(PrNH2)].