H3As=O and its hydrocarbyl derivatives (analogously arsine @I02948@ and arsine @S06102@), e.g. (CH3)3As=O trimethylarsine oxide or trimethylarsane oxide.
See:
imides
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1319 [Terms] [Paper]