Synthesis and Characterization of Nickel(II) and Palladium(II) Complexes of Novel Tetraaza[14]-Annulene-Tetracarbonitrile

Abstract

The nickel(II) and palladium(II) complexes for 6,13-di-n-propyl-l,8-dihydro-1,4,8,11-tetraazacyclotetradeca-2,4,6,9, 11.13-hexaene-2,3,9,10-tetracarbonitrile have been prepared. The mass spectra establish the existence of the parent ion. In view of the C ≡ N stretching mode, the nitrile groups at 2-,3-,9-, and 10-positions are not coordinated to a metal(II). In NMR spectra, the amine proton signal is observed in a much lower field owing to electron-withdrawing effect of the nitrile groups. Judging from d → d∗ transitions, the metal(II) complexes have the square-planar configurations.