Perimidin-2-ylidene rhodium(I) complexes; unexpected halogen exchange and catalytic activities in transfer hydrogenation reaction


AKINCI P. A. , GÜLCEMAL S. , KAZHEVA O. N. , ALEXANDROV G. G. , DYACHENKO O. A. , CETINKAYA E., ...Daha Fazla

JOURNAL OF ORGANOMETALLIC CHEMISTRY, cilt.765, ss.23-30, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 765
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.jorganchem.2014.04.033
  • Dergi Adı: JOURNAL OF ORGANOMETALLIC CHEMISTRY
  • Sayfa Sayıları: ss.23-30

Özet

Four new [(NHC)RhCl(COD)] (NHC = perimidin-2-ylidene; COD = 1,5-cyclooctadiene) rhodium complexes (4a-c and 5a) have been prepared by the reaction of [Rh(mu-OMe)(COD)](2) with perimidinium bromides (2a-c and 3a). The halogen exchange, abstracted from 1,2-dichloroethane was observed during the reaction and [(NHC)RhCl(COD)] complexes were obtained instead of [(NHC)RhBr(COD)]. All ligand precursors and complexes have been fully characterized by H-1, C-13 NMR, IR spectroscopy, elemental analysis and mass spectroscopy. X-ray diffraction studies on single crystals of 4a and 5a confirm the square planar geometry. The nu((CO)) values of [(NHC)RhCl(CO)(2)] complexes (6a-c and 7a) revealed that the NHC ligands are not good sigma-donors. Transfer hydrogenation (TH) reaction of aliphatic and aromatic ketones has been comparatively studied by using complexes 4a-c and 5a as catalysts. (C) 2014 Elsevier B.V. All rights reserved.