TY - JOUR
T1 - On mixed-valence dinuclear PtII, PtIII nucleobase complexes derived from cis-diamineplatinum(II)
T2 - Effect of steric bulk of amine ligands on the Pt-oxidation state
AU - Peilert, Matthias
AU - Erxleben, Andrea
AU - Lippert, Bernhard
PY - 1996
Y1 - 1996
N2 - A series of closely related dinuclear (head-head) PtII complexes of general composition cis-[a2PtL2Pta′2]2+ with a,a′ = NH3 or CH3NH2 and L = 1-methyluracilate-N3,O4 (1-MeU) or 1-methylthyminate-N3,O4 (1-MeT) has been prepared and the solution behavior toward CeIV oxidation studied. The X-ray crystal structure of a representative example cis-[(CH3NH2)2Pt(1-MeU)2Pt(CH 3NH2)2](ClO4)2·0.5 H2O (1b), has been determined: Monoclinic, space group P21/c, a = 11.907(7) Å, b = 19.087(14) Å, c = 12.525(7) Å, β = 90.49(4)°, Z = 4. Oxidation of these diplatinum(II) complexes ([Pt2.0]2) with CeIV in aqueous solution to the corresponding diplatinum(III) species ([Pt3.0]2) proceeds via tetranuclear [Pt2.25]4 or dinuclear [Pt2.5]2 mixed-valence state compounds, depending on the nature of the a′ ligands: with a′ = NH3, blue green [Pt2.25]4 forms, whereas with a′ = CH3NH2, purple [Pt2.5]2 represents the intermediate. This difference is interpreted in terms of differences in bulk between NH3 and CH3NH2 ligands trans to the O(4) positions of the bridging nucleobases which influence the ability of dinuclear species to associate via the O(4)2 Pt a2′ faces.
AB - A series of closely related dinuclear (head-head) PtII complexes of general composition cis-[a2PtL2Pta′2]2+ with a,a′ = NH3 or CH3NH2 and L = 1-methyluracilate-N3,O4 (1-MeU) or 1-methylthyminate-N3,O4 (1-MeT) has been prepared and the solution behavior toward CeIV oxidation studied. The X-ray crystal structure of a representative example cis-[(CH3NH2)2Pt(1-MeU)2Pt(CH 3NH2)2](ClO4)2·0.5 H2O (1b), has been determined: Monoclinic, space group P21/c, a = 11.907(7) Å, b = 19.087(14) Å, c = 12.525(7) Å, β = 90.49(4)°, Z = 4. Oxidation of these diplatinum(II) complexes ([Pt2.0]2) with CeIV in aqueous solution to the corresponding diplatinum(III) species ([Pt3.0]2) proceeds via tetranuclear [Pt2.25]4 or dinuclear [Pt2.5]2 mixed-valence state compounds, depending on the nature of the a′ ligands: with a′ = NH3, blue green [Pt2.25]4 forms, whereas with a′ = CH3NH2, purple [Pt2.5]2 represents the intermediate. This difference is interpreted in terms of differences in bulk between NH3 and CH3NH2 ligands trans to the O(4) positions of the bridging nucleobases which influence the ability of dinuclear species to associate via the O(4)2 Pt a2′ faces.
KW - 1-methyluracil
KW - Crystal structure
KW - Mixed-valence platinum complexes
KW - Nucleobase complexes
UR - https://www.scopus.com/pages/publications/0008088399
U2 - 10.1002/zaac.19966220212
DO - 10.1002/zaac.19966220212
M3 - Article
AN - SCOPUS:0008088399
SN - 0044-2313
VL - 622
SP - 267
EP - 274
JO - Zeitschrift fur Anorganische und Allgemeine Chemie
JF - Zeitschrift fur Anorganische und Allgemeine Chemie
IS - 2
ER -