This ERC-StG 2014 proposal, SILION, outlines a strategy for the one-pot synthesis, characterization, and reactivity investigation of a positively charged, electron-deficient, highly Lewis acidic, cationic silicon(II) species, denoted “silyliumylidene ions”. Silyliumylidene ion has only four valence electrons, consisting of a lone pair of electrons and two vacant orbitals on the central silicon ato...