The new compound
4′-(diphenylphosphino)-2,2′
![](https://www.rsc.org/images/entities/char_200a.gif)
:
![](https://www.rsc.org/images/entities/char_200a.gif)
6′,2
″-terpyridine L
1
has been prepared; in solution it
readily oxidises to the corresponding phosphine oxide, L
2
.
The reaction between L
1
and
FeCl
2
·4H
2
O yielded salts containing
[FeL
1
2
]
2+
, however, oxidation resulted
in the formation of [FeL
2
2
]
2+
. The
corresponding ruthenium(
II) complex of L
2
has also
been prepared and structurally characterised as the hexafluorophosphate
salt; attempts to prepare [RuL
1
2
]
2+
always resulted in oxidation of the ligand to L
2
. The
reaction of L
1
with cobalt(
II) acetate gave
[CoL
1
2
]
2+
which has been isolated as
the hexafluorophosphate salt. The complexes have been characterised by
IR and NMR spectroscopies, mass spectrometry and elemental analysis.
Compound L
1
also reacts with
[PdCl
2
(NCMe)
2
] to give
trans-[PdCl
2
L
1
2
] which has
been fully characterised; results of an X-ray diffraction study confirm
the trans configuration of the complex.