The syntheses of the chloro complexes [Ru(
5-C
5R
5)Cl(L)] (R = H, Me; L = phosphinoamine ligand) (
1a-
d) havebeen carried out by reaction of [(
5-C
5H
5)RuCl(PPh
3)
2] or {(
5-C
5Me
5)RuCl}
4 with the corresponding phosphinoamine(
R,
R)-1,2-bis((diisopropylphosphino)amino)cyclohexane),
R,
R-dippach, or 1,2-bis(((diisopropylphosphino)amino)ethane),dippae. The chloride abstraction reactions from these compounds lead to different products depending on thestarting chlorocomplex and the reaction conditions. Under argon atmosphere, chloride abstraction from [(
5-C
5Me
5)RuCl(
R,
R-dippach)] with NaBAr'
4 yields the compound [(
5-C
5Me
5)Ru(
3P,
P'
-(R,
R)-dippach)][BAr'
4] (
2b) which exhibitsa three-membered ring Ru-N-P by a new coordination form of this phosphinoamine. However, under the sameconditions the reaction starting from [(
5-C
5Me
5)RuCl(dippae)] yields the unsaturated 16 electron complex [(
5-C
5Me
5)Ru(dippae)][BAr'
4] (
2d). The bonding modes of
R,
R-dippach and dippae ligands have been analyzed byDFT calculations. The possibility of tridentate P,N,P-coordination of the phosphinoamide ligand to a fragment [(
5-C
5Me
5)Ru]
+ is always present, but only the presence of a cyclohexane unit in the ligand framework converts thisbonding mode in a more favorable option than the usual P,P-coordination. Dinitrogen [(
5-C
5R
5)Ru(N
2)(L)][BAr'
4](
3a-
d) and dioxygen complexes [(
5-C
5H
5)Ru(O
2)(
R,
R-dippach)][BPh
4] (
4a) and [(
5-C
5Me
5)Ru(O
2)(L)][BPh
4] (
4b,
d)have been prepared by chloride abstraction under dinitrogen or dioxygen atmosphere, respectively. The presenceof 16 electron [(
5-C
5H
5)Ru(
R,
R-dippach)]
+ species in fluorobenzene solutions of the corresponding dinitrogen ordioxygen complexes in conjunction with the presence of [BAr'
4]
- gave in some cases a small fraction of [Ru(
5-C
5H
5)(
6-C
6H
5F)][BAr'
4] (
5a), which has been isolated and characterized by X-ray diffraction.