Synthesis of Cyclometalated Palladium (II) and Platinum (II) Complexes Using 2-Substituted 8-Quinolinols Congaining C-Donor Atoms and Steric Interaction between the Ligands

摘要

Cyclometalated complexes of 2-substituted 8-quinolinols possessing two or three carbon side chains have been prepared in the presence of a presence of a second ligand. The 5,5- or 5,6--chelate ring system containing a Pd (II)- or Pt(II)-C(sp~3) bond is very stable. There are notable steric interactions among three adjacent substituents. The X-ray structure analysis of the complex containing a bulky second ligand, such as PPh_3, reveals a remarkable distortion within the Pd-coordination plane. The steric repulsion was observed also in solution by ~1H-NMR spectroscopy. A novel cyclometalated palladium complex of 3'-azido - 3'-deoxythymidine(AZT) was prepared and the steric interaction was investigated by H-H COSY analysis.