Metallole

Metalloles are metallacycle derivatives of cyclopentadiene in which the carbon atom at position 5, the saturated carbon, is replaced by a heteroatom. In contrast to its parent compound, the numbering of the metallole starts at the heteroatom. Some of these compounds are described as organometallic compounds, but in the list below quite a number of metalloids are present too. Some metalloles are fluorescent. Polymeric derivatives of pyrrole and thiophene are of interest in molecular electronics. Metalloles, which can also be viewed as structural analogs of pyrrole, include:

Name	M	d, Å	d, Å	α, °	E, kJ/mol
Pyrrole	N	1.37	1.01	110	0
Phosphole	P	1.81	1.425	90.5	67
Arsole	As	1.94	1.53	86	125
Stibole	Sb	2.14	1.725	80.5	160
Bismole	Bi	2.24	1.82	78	220

Arsole, a moderately-aromatic arsenic analog
Bismole, a bismuth analog
Borole, a boron analog
Furan, an oxygen analog
Gallole, a gallium analog
Germole, a germanium analog
Phosphole, a phosphorus analog
Pyrrole, a nitrogen analog
Selenophene, a selenium analog
Silole, a silicon analog
Stannole, a tin analog
Stibole, an antimony analog
Tellurophene, a tellurium analog
Plumbole, a lead analog
Thiophene, a sulfur analog
Titanacyclopentadiene, e.g.
Zirconacyclopentadiene, e.g.
Ferrole, an iron analog