Vanadium(II) porphyrins: synthesis and physicochemical properties. Crystal structures of bis(dimethylphenylphosphine)- and bis(tetrahydrofuran)-(2,3,7,8,12,13,17,18-octaethylporphyrinato)-vanadium(II)

Abstract

The vanadium(II) porphyrins [V^IIL(PPhMe₂)₂] and [V^IIL(thf)₂] have been prepared from [V^IVLX₂][L = 2,3,7,8,12,13,17,18-octaethylporphyrinate (oep), meso-tetraphenylporphyrinate (tpp), meso-tetra-m-tolylporphyrinate (tmtp), or meso-tetra-p-tolylporphyrinate (tptp); X = halide]. The crystal structures of [V^II(oep)(PPhMe₂)₂] and [V^II(oep)(thf)₂] have been solved by X-ray diffraction methods. Crystals of [V^II(oep)(PPhMe₂)₂] are orthorhombic, space group Pbca, with a= 14.540(2), b= 21.431 (3), c= 15.305(5)Å, and Z= 4. Crystals of [V^II(oep)(thf)₂] are triclinic, space group P, with a= 10.078(1), b= 10.202(3), c= 10.815(1)Å, α= 75.54(1), β= 87.63(1), γ= 66.43(1)°, and Z= 1. In both complexes the two non-porphyrin ligands are in a trans configuration. The vanadium atom, being on an inversion centre, lies in the perfect plane of the four nitrogen atoms and is octahedrally co-ordinated {V^II–P 2.523(1), V^II–O 2.174(4), mean V–N 2.046(4)Å for [V^II(oep)(thf)₂] and 2.051(4)Å for [V^II(oep)(PPhMe₂)₂]}.