Ruthenium(II) and Ruthenium(IV) Complexes Containing κ¹-<i>P</i>-, κ²-<i>P,O</i>-, and κ³-<i>P,N</i><i>,</i><i>O</i>-Iminophosphorane-Phosphine Ligands Ph₂PCH₂P{NP(O)(OR)₂}Ph₂ (R = Et, Ph): Synthesis, Reactivity, Theoretical Studies, and Catalytic Activity in Transfer Hydrogenation of Cyclohexanone

[{Ru(η6-p-cymene)(μ-Cl)Cl}2] and [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2] react with Ph2PCH2P{NP(O)(OR)2}Ph2 (R =
Et (1a), Ph (1b)) affording complexes [Ru(η6-p-cymene)Cl2(κ1-P-Ph2PCH2P{NP(O)(OR)2}Ph2)] (R = Et (2a),
Ph (2b)) and [Ru(η3:η3-C10H16)Cl2(κ1-P-Ph2PCH2P{NP(O)(OR)2}Ph2)] (R = Et (6a), Ph (6b)). While treatment
of 2a with 1 equiv of AgSbF6 yields a mixture of [Ru(η6-p-cymene)Cl(κ2-P,O-Ph2PCH2P{NP(O)(OEt)2}Ph2)][SbF6] (3a) and [Ru(η6-p-cymene)Cl(κ2-P,N-Ph2PCH2P{NP(O)(OEt)2}Ph2)][SbF6] (4a), [Ru(η6-p-cymene)Cl(κ2-P,O-Ph2PCH2P{NP(O)(OPh)2}Ph2)][SbF6] (3b) and [Ru(η3:η3-C10H16)Cl(κ2-P,O-Ph2PCH2P{NP(O)(OR)2}Ph2)][SbF6] (R = Et (7a), Ph (7b)) are selectively formed from 2b and 6a,b. Complexes [Ru(η6-p-cymene)(κ3-P,N,O-Ph2PCH2P{NP(O)(OR)2}Ph2)][SbF6]2 (R = Et (5a), Ph (5b)) and [Ru(η3:η3-C10H16)(κ3-P,N,O-Ph2PCH2P{NP(O)(OR)2}Ph2)][SbF6]2 (R = Et (8a), Ph (8b)) have been prepared using 2 equiv of AgSbF6. The reactivity of
3−5a,b has been explored allowing the synthesis of [Ru(η6-p-cymene)X2(κ1-P-Ph2PCH2P{NP(O)(OR)2}Ph2)]
(R = Et, Ph; X = Br, I, N3, NCO (9−12a,b)). The catalytic activity of 2−8a,b in transfer hydrogenation of
cyclohexanone, as well as theoretical calculations on the models [Ru(η6-C6H6)Cl(κ2-P,N-H2PCH2P{NP(O)(OH)2}H2)]+ and [Ru(η6-C6H6)Cl(κ2-P,O-H2PCH2P{NP(O)(OH)2}H2)]+, has been also studied.