Stable silyl, germyl, and stannyl cations, radicals, and anions: heavy versions of carbocations, carbon radicals, and carbanions.

The rapidly growing chemistry of the cations, radicals, and anions based on the group 14 elements heavier than carbon (Si, Ge, Sn, and Pb) is one of the most important organometallic fields. Recent developments in this research area moved such species from the class of short-lived reactive intermediates to the class of easily accessible, isolable, and fully characterizable compounds. In this Account, we deal with the major accomplishments in the field of the stable representatives of "heavy" cations, radicals, and anions.