Solid-State Structures of ortho-Carboran-1-yl Lithium Complexes Bearing Ethereal Ligands

(o-Carboran-1-yl)lithium species are key intermediates for the synthesis of carborane-functionalized molecules, yet structural information on their ether-coordinated forms has remained largely limited to spectroscopic and computational prediction. Herein, we report the isolation and single-crystal X-ray diffraction analysis of (ocarboran-1-yl)lithium complexes bearing diverse ethereal ligands, e.g., diethyl ether, 4-methyltetrahydropyran, (-)-menthyl methyl ether, methyl tert-butyl ether, and 1,2-dimethoxyethane (DME). The Li:ether stoichiometry varies with the volatility, α-carbon steric demand, and denticity of the ether ligands, encompassing 1:3 and 1:2 ethercoordinated monomers, a 2:3 μ-DME-bridged dimer, and a 1:1 polymeric form featuring chelating B-H coordination by a neighboring carborane.