Synthesis and crystal structures of the heptamagnesium cationic and mixed magnesium(II)/nickel(II) molecular 2-tetrahydrofurfuroxo aggregates

Abstract

Direct reaction of metallic magnesium with 2-tetrahydrofurfuryl alcohol (THFFOH) produces the alkoxo magnesium compound of composition Mg(THFFO)₂, 1. Compound 1 reacts with FeCl₂ and NiCl₂ to create two different species: the ionic [Mg₇(µ₃,η²-THFFO)₆(µ,η²-THFFO)₆][FeCl₄]·3CH₂Cl₂, 2, and the mixed [(Mg^II/Ni^II)₄(µ₃,η²-THFFO)₄Cl₄(C₂H₅OH)₄]·0.5C₂H₅OH molecular complex 3, respectively. Complexes 2 and 3 have been structurally characterized. The cation of compound 2 consists of a Mg₇ unit comprising a central Mg atom held within a Mg₆ puckered hexagon by six µ₃-O(alkoxo) groups from the THFFO ligands. Complex 3 consists of four crystallographically independent distorted octahedral metal sites, distributed unequally (Mg_0.7 and Ni_0.3), which together with alkoxo oxygen atoms form a cubane-like framework.