Rearrangement of a Ge(II) aryloxide to yield a new Ge(II) oxo-cluster [Ge6(μ3-O)4(μ2-OC6H2-2,4,6-Cy3)4] (NH3)0.5: main group aryloxides of Ge(II), Sn(II), and Pb(II) [M(OC6H2-2,4,6-Cy3)2]2 (Cy = cyclohexyl)

The new Ge(II) cluster [Ge-6(mu(3)-O)(4)(mu(2)-OC6H2-2,4,6-Cy-3)(4)](NH3)(0.5) (1) and three divalent Group 14 aryloxide derivatives [Ge(OC6H2-2,4,6-Cy-3)(2)](2) (2), [Sn(OC6H2-2,4,6-Cy-3)(2)](2) (3), and [Pb(OC6H2-2,4,6-Cy-3)(2)](2) (4) of the new tricyclohexylphenyloxo ligand, [(-OC6H2-2,4,6-Cy-3)(2)](2) (Cy = cyclohexyl), were synthesized and characterized. Complexes 1-4 were obtained by reaction of the metal bissilylamides M(N(SiMe3)(2))(2) (M = Ge, Sn, Pb) with 2,4,6-tricyclohexylphenol in hexane at room temperature. If the freshly generated reaction mixture for the synthesis of 2 is stirred in solution for 12 h at room temperature, the cluster [Ge-6(mu(3)-O)(4)(mu(2)-OC6H2-2,4,6-Cy-3)(4)](NH3)(0.5) (1), which features a rare Ge6O8 core that includes ammonia molecules in non-coordinating positions, is formed. Complexes 3 and 4 were also characterized via Sn-119 {H-1} NMR and Pb-207 NMR spectroscopy and feature signals at -280.3 ppm (Sn-119{H-1}, 25 degrees C) and 1541.0 ppm (Pb-207, 37 degrees C), respectively. The spectroscopic characterization of 3 and 4 extends known Sn-119 parameters for dimeric Sn(II) aryloxides, but data for Pb-207 NMR spectra for Pb(II) aryloxides are rare. We present also a rare VT-NMR study of a homoleptic 3-coordinate Pb(II) aryloxide. The crystal structures of 2, 3, and 4 feature interligand H center dot center dot center dot H contacts that are similar in number to those of related transition metal derivatives despite the larger size of the group 14 elements.