Quasi-octahedral complexes of pentamethylcyclopentadienyliridium(iii) bearing bis(diphenylphosphinomethyl)phenylphosphine (dpmp)

Abstract

Reaction of [Cp*IrCl2]2 (1) with dpmp in the presence of KPF6 afforded a binuclear complex [Cp*IrCl(dpmp-P1,P2;P3)IrCl2Cp*](PF6) (2) (dpmp =(Ph2PCH2)2PPh). The mononuclear complex [Cp*IrCl(dpmp-P1,P2)](PF6) (4) was generated by the reaction of [Cp*IrCl2(BDMPP)](BDMPP =PPh[2,6-(MeO)2C6H3]2) with dpmp in the presence of KPF6. These mono- and binuclear complexes have four-membered ring structures with a terminal and a central P atom of the dpmp ligand coordinated to an iridium atom as a bidentate ligand. Since there are two chiral centers at the Ir atom and a central P2 atom, there are two diastereomers that were characterized by spectrometry. Complexes anti-4 and syn-4 reacted with [Cp*RhCl2]2 or [(C6Me6)RuCl2]2, giving the corresponding mixed-metal complexes, anti- and syn- [Cp*IrCl(dppm-P1,P2;P3)MCl2L](PF6) (6: M = Rh, L = Cp*; 7: M = Ru, L = C6Me6). Treatment with AuCl(SC4H8) gave tetranuclear complexes, anti- and syn-8 [[Cp*IrCl(dppm-P1,P2;P3)AuCl]2](PF6)2 bearing an Au-Au bond. Reaction of anti- with PtCl2(cod) generated the trinuclear complex anti-9, anti-[[Cp*IrCl(dppm-P1,P2;P3)]2PtCl2](PF6)2. These reactions proceeded stereospecifically. The P,O-chelated complex syn-[Cp*IrCl(BDMPP-P,O)] (syn-10)(BDMPP-P,O = PPh[2,6-(MeO)2C6H3][2-O-6-(MeO)C6H3]2) reacted with dpmp in the presence of KPF6, generating the corresponding anti-complex as a main product as well as a small amount of syn-complex, [Cp*Ir(BDMPP-P,O)(dppm-P1)](PF6) (11). The reaction proceeded preferentially with inversion. The reaction processes were investigated by PM3 calculation. anti- was treated with MCl2(cod), giving anti-[Cp*Ir(BDMPP-P,O)(dppm-P1;P2,P3)MCl2](PF6)(14: M = Pt; 15: M = Pd), in which the MCl2 moiety coordinated to the two free P atoms of anti-11. The X-ray analyses of syn-2, anti-2, anti-4, anti-8 and anti-11 were performed.

Dehydrogenative Coupling of a Tertiary Silane Using Wilkinson's Catalyst

“…Two of the three remaining positions are occupied by the hydrido and the triphenylphosphine ligand. A hydrogen atom of one of the aromatic rings of the triphenylphosphine (H27) occupies the last coordination site via a weak Rh ··· H–C interaction, [C27–H27 1.185 Å, Rh1–H27 2.329 Å, Rh1–C27 3.129 Å, Rh1–H27–C27 122.4°]. Considering these distances and bond angles, this interaction would be in the border of agostic and anagostic interaction .…”

Half-sandwich iridium complexes—Synthesis and applications in catalysis

“…In its reaction with [Cp*IrCl 2 ] 2 in the presence of KPF 6 , a 1:1 mixture of two diastereomers, anti-RR/SS and syn-RS/SR, was formed (145a and 145b, Scheme 36). The syn-diastereomer was formed kinetically; but the anti-diastereomer was thermodynamically more stable [55].…”

“…The syn-and anti-form refers to the R group and Cl/dpmp occupying the same or the opposite side. The relative stereoconfiguration at iridium and phosphorus of the P,O-chelate was determined to be R Ir S P /S Ir R P by X-ray crystallography [55]. Thus the reaction proceeds preferentially with stereochemical inversion.…”

Synthesis and Structures of Iron(II) Metallacycles Based on a PNPNP Framework

“…The structure of 6 can be compared to that of closely related [Cp*Rh(κ 3 -P 1 ,P 2 ,P 3 -dpmp)](OTf) 2 , where dpmp has a PCPCP scaffold (Chart 1); the angles of P 1 −Rh−P 2 , P 3 − Rh−P 2 , and P 1 −Rh−P 3 are 71.0(1), 70.7(1) and 95.2(1)°, respectively. 22 This complex and its iridium version 23 were prepared from the reaction of the corresponding [Cp*MCl(κ 2 -P 1 ,P 2 -dpmp)]PF 6 complex with AgOTf through intramolecular coordination of the terminal P 3 group. UV irradiation of the cis isomer 3a under the same conditions used with 3b also led to the formation of the same product 6 in good yield.…”