Synthesis of Bis(2,6-dinitroaryl)palladium(II) and Mono(2,6-dinitroaryl)platinum(II) Complexes. A New Example of the Transphobia Effect and of Transmetalation from Pt to Hg

The reaction of [Pd(κ2-Ar)(O,O-acac)] (κ2-Ar = κ2-C,O-C6(NO2)2-2,6-(OMe); 1) with 1 equiv of RNC gives [Pd(κ2-Ar)(O,O-acac)(CNR)] [R = Xy (2a), tBu (2b)] and with 4 equiv of XyNC, trans-[Pd(κ1-Ar)2(CNXy)2] (κ1-Ar = κ1-C-C6(NO2)2-2,6-(OMe); 3). This complex has also been obtained (1) by reacting Tl(acac) with 1 equiv of trans-[Pd(κ1-Ar)Cl(CNXy)2] (4), obtained in turn by reacting trans-(NMe4)2[Pd(κ1-Ar)Cl(µ-Cl)]2 (5) with 4 equiv of XyNC or (2) by reacting [Pd(κ1-Ar)(C-acac)(phen)] (6) with 4 equiv of XyNC. cis-[Pt(κ2-Ar)(κ1-Ar)(PPh3)] (7) reacts (1) with Hg(OAc)2 (1:1) to afford a mixture of [Hg(Ar)(OAc)], cis-[{Pt(κ1-Ar)(PPh3)}2(µ-OH)(µ-OAc)] (8), and trans-[{Pt(κ1-Ar)(PPh3)}2(µ-OH)2] (9) or (2) with HgCl2 (1:1) to give trans-[{Pt(κ1-Ar)(PPh3)}2(µ-Cl)2] (10), which reacts with an excess of Ag(OAc) to give 8. The reaction of 10 with excess of KOH, or with Tl(acac) (1:1) gives 9. Reaction of palladium complex 5 with 2 equiv of Hg(OAc)2 affords trans-[Pd(κ2-Ar)(µ-OAc)]2 (11). The crystal structures of 2a, 2b, 3, 5, 8, 9, and 11 have been determined.