N1-coordination in palladium(II) and platinum(II) complexes with 9-methylhypoxanthine: crystal structures and theoretical calculations

Dalton Trans. 2009 Nov 21:(43):9637-44. doi: 10.1039/b915427b. Epub 2009 Sep 26.


The synthesis of the new palladium and platinum complexes with 9-methylhypoxanthine (9-mhypH) of the type [M(dmba)(L)(9-mhypH-N7)]ClO(4) [dmba = N,C-chelating 2-(dimethylaminomethyl)phenyl; M = Pd or Pt; L = DMSO, PPh(3) or PTA (PTA = 1,3,5-Triaza-7-phosphaadamantane)] is reported. Pd(II) and Pt(II) complexes with the anion of 9-mhypH of the type [M(dmba)(L)(9-mhyp-N1)] [L = PPh(3) or PTA] have also been prepared. The crystal structures of [Pt(dmba)(PPh(3))(9-mhypH-N7)]ClO(4) and [Pt(dmba)(PPh(3))(9-mhyp-N1)] have been established by X-ray diffraction. The last complex is the first structurally authenticated example of N1 coordination of 9-methylhypoxanthine to platinum. DFT-based calculations at the BP86/def2TZVP level predict a most favourable interaction (both kinetically and thermodynamically) of the metal(II) centre with N7 in the neutral ligand 9-mhypH, but with N1 in the deprotonated ligand 9-mhyp(-) in agreement with the experimentally observed preference in neutral conditions or upon basic treatment, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Databases, Factual
  • Hypoxanthines / chemistry*
  • Models, Molecular
  • Molecular Conformation
  • Nitrogen / chemistry*
  • Organoplatinum Compounds / chemical synthesis
  • Organoplatinum Compounds / chemistry*
  • Palladium / chemistry*
  • Platinum / chemistry*
  • Quantum Theory


  • 9-methylhypoxanthine
  • Hypoxanthines
  • Organoplatinum Compounds
  • Platinum
  • Palladium
  • Nitrogen