Gehinderte Ligandenbewegungen in Übergangsmetallkomplexen, XII1 Tricarbonyl-η6-N-carbäthoxyazepin-chrom(0), -molybdän(0) und -wolfram(0) / Hindered Ligand Motions in Transition Metal Complexes, XII Tricarbonyl-η6-N-carbethoxyazepine-chromium(0), -molybdenum(0) and -tungsten(0)

Abstract

Tricarbonyl-η6-N-carbethoxyazepine-metal(0) complexes of chromium, molybdenum and tungsten are formed, when tricarbonyl-trisacetonitrile-chromium(0), tricarbonyldiglyme-molybdenum(0) and tricarbonyl-trisacetonitrile-tungsten(0), respectively, are treated with N-carbethoxyazepine. According to the 1H and 13C NMR spectra of the N-carbethoxyazepine metal complexes two different ligand motions can be activated thermally. The carbethoxy group rotates around the C-N-bond (Δ G300 ≠ = 64.6 to 66.1 kJ • mole-1) and the azepine ligand itself moves against the tricarbonyl metal groups (Δ G250≠ 45.6-52.1 kJ • mole-1).