The mononuclear hydride
AsH5, systematically named λ5-arsane, and its hydrocarbyl derivatives. By extension the term also applies to arsonium ylides.
See: arsanes, ylides
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1320 (https://doi.org/10.1351/pac199567081307)