Palladium(II)‐ und Platin(II)‐Komplexe mit dem Antimalariamittel Mefloquin als Liganden

Metal Complexes of Biologically Important Ligands. CXXVI. Palladium(II) and Platinum(II) Complexes with the Antimalarial Drug Mefloquine as Ligand The coordination sites of the antimalarial drug mefloquine (L) were studied. Reactions of the chloro bridged complexes (allyl)Pd(μ‐Cl)₂Pd(allyl) and (R₃P)(Cl)M(μ‐Cl)₂M(Cl)(PR₃) (M = Pd, Pt) with racemic mefloquine give the compounds (allyl)(Cl)Pd(L) ( 1 ), Cl₂(Et₃P)Pt(L) ( 2 ) and Cl₂(Et₃P)Pd(L) ( 3 ) with coordination of the piperidine N atom of mefloquine. In the presence of NaOMe the N,O‐chelate complexes Cl(Et₃P)Pt(L–H⁺) ( 4 ) and Cl(R₃P)Pd(L–H⁺) ( 5 , 6 , R = Et, nBu) were obtained. Protection of the piperidine N atom of mefloquine by protonation allows the synthesis of the complexes Cl₂(Et₃P)Pt(L + H⁺) ( 7 ) in which mefloquine is coordinated via the quinoline N atom. The structures of 2 , 3 and 4 were determined by X‐ray diffraction analysis. In the crystal of 4 pairs of enantiomers are found which are linked by two hydrogen bridges between the amine group and the chloro ligand.     

[Pt(topy)(Htopy)(ONO2)] complex (Htopy = 2‐p‐tolylpyridine) and its analogs: 195Pt NMR spectra and fabrication of light‐emitting devices

We report fast, high‐yield syntheses of a series of [Pt(C^∧N)(HC^∧N)X] complexes, where HC^∧N is 2‐phenylpyridine (Hppy) or 2‐p‐tolylpyridine (Htopy) and X^? is Cl^?, Br^?, I^?, ONO₂^?, NO₂^? or SCN^?. The structure of [Pt(topy)(Htopy)(ONO₂)] was analyzed by single‐crystal X‐ray diffraction. Substitution of Cl^? with Br^? or I^? in our complexes shifted the ¹⁹⁵Pt NMR peaks upfield in the order Cl^? < Br^? < I^?, but the magnitudes of their shifts were one‐tenth those observed for non‐cyclometalated platinum(II) complexes. As the two nitrato complexes showed strong emissions in acetonitrile solution—three to six times those of other complexes—they were used to fabricate OLEDs. Although their emissions were not particularly strong, devices fabricated with platinum(II) complexes containing bulky ligands emitted green light with a short lifetime (τ). Copyright © 2009 John Wiley & Sons, Ltd.