Transition-metal complexes of the macrocyclic ligand 5,7,12,14-tetra-methyl- 1,4,8,11-tetra-azacyclotetradeca-4,11-diene

Abstract

The reaction of the monohydroperchlorate salt of 1,2-diaminoethane with pent-3-en-2-one in methanol solution gives the dihydroperchlorate salt of 5,7,12,14-tetramethyl-1,4,8,11-tetra-azacyclotetradeca-4,11-diene (L·2HClO₄). The reaction is not completely stereospecific and ca. 15% of the C-rac-ligand is formed in conjunction with the C-meso-ligand. A series of octahedral cobalt(III) complexes of the general type trans-[CoLX₂]ⁿ⁺(X = Cl^–, Br^–, [NO₂]^–, [CN]^–, [N₃]^–, [MeCO₂]^–, NH₃, or Cl^–[NO₂]^–) have been prepared by anion-metathesis reactions with the C-meso-N-meso(e–e) stereoisomer of trans-[CoCl₂L]⁺, and n.m.r. studies confirm this configuration in the other complexes. The preparations of the µ-peroxo-complex [{CoL(OH₂)}₂O₂][ClO₄]₄·H₂O and the four-co-ordinate complex [CuL][ClO₄]₂ are also described. The stereochemistry of the various complexes is discussed and i.r. and d–d spectra are reported.