Abstract
New water soluble Ru
II
complexes,
e.g.
RuHl(tppts)
3
[tppts =(
m
-NaSO
3
C
6
H
4
)
3
P], exhibit in the presence of various salts an extremely high catalytic activity in the hydrogenation of aldehydes, mechanistic studies indicating clearly that the salt effect occurs both
via
the cation and the anion in the catalytic cycle; the electrophilic cation favours an unusual type of aldehyde coordination and reaction mechanism as the anion modifies the coordination sphere around the ruthenium atom.