M. Goto, M. Sumimoto, Takashi Matsumoto
Jul 1, 2000
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0
Influential Citations
9
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Square-planar complexes with the formula [Pt(L1) (L2)]X2, where L1 is di(ammine) or 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) and L2 is N-ethyl-1,2-ethanediamine (Eten) or N-benzyl-1,2-ethanediamine (Been), and X = NO3- or Cl-, were prepared. NMR measurements of D2O solutions of these complexes showed that the N-ethyl and N-benzyl groups are forced to take a pseudo axial disposition due to an intramolecular repulsion from hydrogen atoms of aromatic diamines for complexes where L1 = bpy or phen and significant upfield shifts due to the ring current effect were observed for the Been complexes. An analysis of coupling with N-H and 195Pt showed that the major rotamer due to rotation around CH2-NH is (-)-syn for the Been with a significant intramolecular stacking between aromatic rings of L1 and L2, but anti- for the Eten complexes. The solvent and temperature dependency of the upfield shift of the Been complexes are described; the protein denaturants, guanidinium chloride, and urea, act to reduce st...