Synthesis of Ruthenium(II) Complexes Containing Tridentate Triamine ('(NNN)over-cap ') and Bidentate Diamine Ligands ((NN)over-cap '): as Catalysts for Transfer Hydrogenation of Ketones


GÜNNAZ S., Ozdemir N., DAYAN S. , DAYAN O., Cetinkaya B.

ORGANOMETALLICS, cilt.30, ss.4165-4173, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 30 Konu: 15
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1021/om200470p
  • Dergi Adı: ORGANOMETALLICS
  • Sayfa Sayıları: ss.4165-4173

Özet

A series of neutral and cationic Ru(II) complexes (1-10), bearing pyridine-based tridentate ('(NNN) over cap'), pyridine-based bidentate ((NN) over cap'), and mixed '(NNN) over cap' + (NN) over cap' ligands, were synthesized by starting from [RuCl2(DMSO)(4)] and [RuCl2(p-cymene)](2) precursors. Solid-state structures of mixed-ligand complexes 9 and 10 were determined by single-crystal X-ray diffraction. Both complexes are unusual in that (NN) over cap' ligands were spontaneously oxidized in air under base-free conditions to give imine-amine bidentate ligands upon replacement of p-cymene by meridional '(NNN) over cap'. The complexes 1-10 were screened for transfer hydrogenation (TH) of aryl ketones with, 2-propanol. The highest catalytic activity was obtained with the :complexes containing tridentate '(NNN) over cap' and 7, which contain nonsulfonated 2-(aminomethyl)pyridine. However, for complexes 6(a-c), containing p-cymene (a facial tridentate ligand), a slower reaction rate was observed.
A series of neutral and cationic Ru(II) complexes (1–10), bearing pyridine-based tridentate ('N??N??N'), pyridine-based bidentate (N??N'), and mixed 'N??N??N' + N??N' ligands, were synthesized by starting from [RuCl2(DMSO)4] and [RuCl2(p-cymene)]2 precursors. Solid-state structures of mixed-ligand complexes 9 and 10 were determined by single-crystal X-ray diffraction. Both complexes are unusual in that N??N' ligands were spontaneously oxidized in air under base-free conditions to give imine-amine bidentate ligands upon replacement of p-cymene by meridional 'N??N??N'. The complexes 1–10 were screened for transfer hydrogenation (TH) of aryl ketones with 2-propanol. The highest catalytic activity was obtained with the complexes containing tridentate 'N??N??N' and 7, which contain nonsulfonated 2-(aminomethyl)pyridine. However, for complexes 6a–c, containing p-cymene (a facial tridentate ligand), a slower reaction rate was observed.