Binuclear ruthenium complexes containing mPTA and alkyl-bis(8-thiotheophylline) derivatives (mPTA = N-methyl-1,3,5-triaza-7-phosphaadamantane)

Abstract

The water-soluble complex [RuClCp(PPh3)(mPTA)](CF3SO3) reacts with the thiopurines, bis(S-8-thiotheophylline)methane (MBTTH2), 1,2-bis(S-8-thiotheophylline)ethane (EBTTH2), and 1,3-bis(S-8-thiotheophylline)propane (PBTTH2), to lead to the binuclear ruthenium(II) complexes [{RuCp(PPh3)(mPTA)}2-μ-(L-κS7,S′7)](CF3SO3)2 where (L = MBTT2− (1), EBTT2− (2), and PBTT2− (3)). All the complexes have been fully characterized by elemental analysis, IR, and multinuclear 1H, 13C{1H}, and 31P{1H} NMR spectroscopy. The cyclic voltammetry of the complexes is characterized by two one-electron oxidative responses (RuII–RuII/RuIII–RuII; RuIII–RuII/RuIII–RuIII) that increase their redox potential when the bis(8-thiotheophylline)-alkyl-bridge growths. The reactivity against DNA and partition coefficient of the complexes were also determined.