An acidic route to silicon cations The simplest silicon cation, with a central Si atom bonded to just three hydrogens, has long eluded bulk synthesis. Wu et al. now report a straightforward route to this molecule by reacting a carborane acid with phenyl silane, producing benzene and the silylium carborane ion pair. A similar protocol offered efficient syntheses of primary and secondary silyl cations through acidic cleavage of Si–phenyl or Si–H bonds. All three products, characterized crystallographically and in solution, manifested weak coordination to bromine substituents of the carboranes. Science , this issue p. 168