Synthesis, characterization, and alkoxide transfer reactivity of dimeric Tl(OR) complexes.

Reaction of LiOCBuPh with TlPF forms the dimeric Tl(OCBuPh) complex, a rare example of a homoleptic thallium alkoxide complex demonstrating formally two-coordinate metal centers. Characterization of Tl(OCBuPh) by H and C NMR spectroscopy and X-ray crystallography reveals the presence of two isomers differing by the mutual conformation of the alkoxide ligands, and by the planarity of the central Tl-O-Tl-O plane. Tl(OCBuPh) serves as a convenient precursor to the formation of old and new [M(OCBuPh)] complexes (M = Cr, Fe, Cu, Zn), including a rare example of T-shaped Zn(OCBuPh)(THF) complex, which could not be previously synthesized using more conventional LiOR/HOR precursors. The reaction of [Ru(cymene)Cl] with Tl(OCBuPh) results in the formation of a ruthenium(ii) alkoxide complex. For ruthenium, the initial coordination of the alkoxide triggers C-H activation at the ortho-H of [OCBuPh] which results in its bidentate coordination. In addition to Tl(OCBuPh), related Tl(OCBu(3,5-MeCH)) was also synthesized, characterized, and shown to exhibit similar reactivity with iron and ruthenium precursors. Synthetic, structural, and spectroscopic characterizations are presented.