In organoiron chemistry, a ferrole is a type of diiron complex containing the (OC)3FeC4R4 heterocycle that is pi-bonded to a Fe(CO)3 group.
They are typically air-stable, soluble in nonpolar solvents, and red-orange in color.
[2] Ferroles typically arise by the reaction of alkynes with iron carbonyls.
Such reactions are known to generate many products, e.g. complexes of cyclopentadienones and para-quinones.
[3][4] Another route involves the desulfurization of thiophenes (SC4R4) by iron carbonyls, shown in the following idealized equation: An unusual route to ferroles involves treatment of Collman's reagent with trimethylsilyl chloride (tms = (CH3)3Si): Some ferroles react with tertiary phosphines to give the substituted flyover complex Fe2(CO)5(PR3)(C4R4CO).