| Abstract: | Homo- and Heterodinuclear α-Pyridonate-bridged Platinum and Palladium Complexes with Bis(N-methylimidazol-2-yl)ketone (BMIK). Crystal Structures of (BMIK)Pt(α-pyridonate)2Pt(BMIK)](NO3)2 · 4H2O, (BMIK)Pd(α-pyridonate)2Pd(BMIK)](NO3)2 · 4H2O, and (BMIK)Pd(α-pyridonate)2Pt/Pd(BMIK)](NO3)2 · 4H2O The isotypic dinuclear complexes (BMIK)Pt(α-pyridonate)2Pt(BMIK)](NO3)2 · 4H2O ( 1 ) (P1 ; a = 12.197(5) Å, b = 12.505(5) Å, c = 12.866(5) Å, α = 88.17(3)°, β = 73.55(3)°, γ = 69.84(3)°; Z = 2) and (BMIK)Pd(α-pyridonate)2Pd(BMIK)](NO3)2 · 4H2O ( 2 ) (a = 12.408(3) Å, b = 12.660(3) Å, c = 12.913(3) Å, α = 89.55(3)°, β = 74.59(2)°, γ = 68.68(2)°) were prepared by reaction of Pt(BMIK)(H2O)2](NO3)2 or Pd(BMIK)(H2O)2](NO3)2 with α-pyridone in aqueous solutions at 40°C and were isolated as red air-stable crystals (BMIK = bis(N-methylimidazol-2-yl)ketone). For the synthesis of mixed crystals of 2 with the heterometal complex (BMIK)Pd(α-pyridonate)2Pt(BMIK)](NO3)2 · 4H2O ( 3 ) (a = 12.430(4) Å, b = 12.648(3) Å, c = 12.907(4) Å, α = 89.64(2)°, β = 74.57(2)°, γ = 68.65(2)°) α-pyridone was reacted with Pd(BMIK)(H2O)2](NO3)2 in a molar ratio of 2 : 1 followed by addition of Pt(BMIK)(H2O)2](NO3)2. The dinuclear cations consist of two M(BMIK) moieties (M = Pt, Pd) bridged by the N- and O-atoms of α-pyridonate, forcing the heterocyclic ring into head-head-orientation. Within the dinuclear cation, the two metal atoms are between 2.840 Å and 2.860 Å apart. The intermolecular distances are between 4.762 Å and 4.837 Å. The coordination geometry of both metal atoms is square-planar with the metal atoms being diplaced slightly from their respective coordination planes toward each other. 1H and 195Pt NMR spectra are reported for the complexes. |
