The complex [Ru{HB(pz)
3
}(cod)Cl] 1
(cod = cycloocta-1,5-diene) reacted with
P(C
6
H
11
)
3
(
![[gt-or-equal]](https://www.rsc.org/images/entities/char_2a7e.gif)
1 equivalent) in
boiling dimethylformamide (dmf) to give the highly air-sensitive
intermediate
[Ru{HB(pz)
3
}{P(C
6
H
11
)
3
}Cl(dmf)] which, on exposure to air in either ethanol
or methanol as the solvent, was converted to the
ruthenium(
III) complexes
[Ru{HB(pz)
3
}{P(C
6
H
11
)
3
}Cl(OCH
2
R)] (R = Me 2a or H
2b) in good yields. Complex 2b has been characterized by X-ray
crystallography. Treatment of 2a or 2b with L = MeCN,
pyridine, CO, P(OMe)
3
, or PMe
3
in
CH
2
Cl
2
afforded the (diamagnetic)
ruthenium(
II) compounds
[Ru{HB(pz)
3
}{P(C
6
H
11
)
3
}(Cl)L] 3–7. Most remarkably, 2a or 2b reacted
also with terminal alkynes HC
![[triple bond, length as m-dash]](https://www.rsc.org/images/entities/char_e002.gif)
CR (R = Ph,
CO
2
Et, Bu
n
or SiMe
3
) giving the neutral
vinylidene complexes
[Ru{HB(pz)
3
}{P(C
6
H
11
)
3
}Cl (
![[double bond, length as m-dash]](https://www.rsc.org/images/entities/char_e001.gif)
C
![[double bond, length as m-dash]](https://www.rsc.org/images/entities/char_e001.gif)
CHR)] 8–11. Preliminary
results of a study of the catalytic activity of 2 are also presented.
Thus, 2a and 2b catalysed the dimerization of some terminal alkynes
HC
![[triple bond, length as m-dash]](https://www.rsc.org/images/entities/char_e002.gif)
CR (R = Ph, CO
2
Et or
SiMe
3
).