Crystal structure of a binuclear mixed-valence ytterbium complex containing a 2-anthracene-substituted phenoxide ligand

Reaction of 2-(anthracen-9-yl)phenol (HOPhAn, 1) with divalent Yb[N(SiMe(3))(2)](2)·2THF in THF–toluene mixtures affords the mixed-valence Yb(II)–Yb(III) dimer {[2-(anthracen-9-yl)phenolato-κO]bis­(tetra­hydro­furan)­ytterbium(III)}-tris­[μ-2-(anthracen-9-yl)phenolato]-κ(4) O:O;κO:1,2-η,κO-{[2-(anthracen-9-yl)phenolato-κO]ytterbium(II)} toluene tris­olvate, [Yb(2)(C(20)H(13)O)(5)(C(4)H(8)O)(2)]·3C(7)H(7) or [Yb(III)(THF)(2)(OPhAn)](μ-OPhAn)(3)[Yb(II)(OPhAn)]·3C(7)H(7) (2), as the major product. It crystallized as a toluene tris­olvate. The Yb—O bond lengths in the crystal structure of this dimer clearly identify the Yb(II) and Yb(III) centres. Inter­estingly, the formally four-coordinate Yb(II) centre shows a close contact with one anthracene C—C bond of a bridging OPhAn ligand, bringing the formal coordination number to five.