Arsole

Arsole, rarely called arsenole, is a chemical compound of the formula C4H5As. The structure is isoelectronic to that of pyrrole except that an arsenic atom is substituted for the nitrogen atom and that arsole is only mildly aromatic. Arsole itself does exist but is rarely found in its pure form. Several substituted analogs called arsoles also exist.

When arsole is fused to a benzene ring, this molecule is called benzarsole. Six arsole molecules linked as a hexamer would be called sexiarsole.