Synthesis and Structural Characterization of closo-exo, exo-nido, and pseudocloso Group 1 Carborane Compounds of the C2B10 System

Abstract

Treatment of 1,2-(C6H5CH2)2-1,2-C2B10H10 with excess Na or K metal in THF at room temperature gave closo-exo-[(C6H5CH2)2C2B10H10]Na2(THF)4 (1) or [closo-exo-{(C6H5CH2)2C2B10H10}K2(THF)2(O2C4H8)0.5]n (2) in good yield after recrystallization from a THF solution or a THF/dioxane solution, respectively. Dissolution of 2 in a THF solution of 18-crown-6 ether afforded an exo-nido-{K(18-crown-6)}{[(C6H5CH2)2C2B10H10]K(18-crown-6)} (3). An equimolar reaction between 1,2-(C6H5CH2)2-1,2-C2B10H10 and K metal or 1,2-(C6H5CH2)2-1,2-C2B10H10 and [(C6H5CH2)2C2B10H10]K2 in THF at room temperature in the presence of 18-crown-6 ether generated two monoanion carborane compounds, [(THF)2K(18-crown-6)][nido-(C6H5CH2)2C2B10H11] (4) and {(THF)K(18-crown-6)}{1-(C6H5CH2)-2-(C6H5CH)-1,2-C2B10H10} (5), respectively. All of these complexes have been fully characterized by various spectroscopic data, elemental analyses, and X-ray diffraction studies. Compounds 1−3 represent the first structurally characterized examples of group 1 sa...