Univalent groups containing carbon, which are thus organic, but which have their free valence at an atom other than carbon. This collective term is seldom used; specific subclasses are more frequently encountered (organothio or organylthio, organogermanium or organylgermanium groups). The synonymous term organoelement groups is occasionally encountered. E.g. phenoxy, acetamido, pyridinio (C₅H₅N⁺), thiocyanato (N≡C–S⁻), trimethylsilyl; but not hydroxyphenyl, aminoacetyl.