Phosphoraneiminato Complexes of Manganese, Iron, and Cobalt with Heterocubane Structures

Abstract

The phosphoraneiminato complexes [MnBr(NPEt₃)]₄ 3, [FeCl(NPEt₃)]₄ 4 and [CoBr(NPEt₃)]₄ 5 were built from the element halides MX₂ and excess trimethylsilyltriethylphosphoraneimine in the presence of potassium fluoride. They form shiny orange (M = Mn), dark brown (M = Fe), and dark green (M = Co) crystals. According to single crystal structure determinations these compounds form M₄N₄ heterocubane frameworks with μ-N-bridges and M–N bond lengths of 213.4 pm (M = Mn), 205.7 pm (M = Fe), and 204.4 pm (M = Co) which lead to intermetallic distances of 295.7 pm (M = Mn), 272.9 pm (M = Fe), and 279.0 pm (M = Co).

Keywords::

• Phosphoraneiminato complexes
• heterocubanes
• manganese compounds
• iron compounds
• cobalt compounds