An improved procedure for syntheses of silyl derivatives of the cubeoctameric silicate anion

The reaction of the Si8O208- silicate anion with X(CH3)(2)SiCl (X=H or CH3) has been studied to develop a cost-effective procedure for synthesizing Si8O20[Si(CH3)(2)X](8) in high yield. Use of hexane as solvent and adjustment of the reaction temperature to ca 20degreesC were found to be effective in promoting the reaction, by which Si8O20[Si(CH3)(2)X](8) could be produced in good yield employing 24 mol of X(CH3)(2)SiCl per mole Of Si8O208-. It was also demonstrated that the yield of Si8O20[Si(CH3)(2)X](8) depends on the amount of solvent, suggesting that the amount is an important factor when scaling up the reaction to produce a large quantity of Si8O20[Si(CH3)(2)X](8). Copyright (C) 2003 John Wiley Sons, Ltd.