Aliphatic diols in the synthesis of bis(cyclopentadienyliron) arene complexes.

Arom. nucleophilic substitution reactions (SNAr) of chloroarene cyclopentadienyliron complex cations with K salts of dihydroxyalkanes in a THF/DMF mixt. gave bis(cyclopentadienyliron) arene dications with aliph. ether linkages. Diols were used to produce the diiron complexes I (R = H, x = 2, 4, 6, 8, 10, 12; R = 4-Cl, x = 2; R = 4-Me, x = 2, 8; R = 3-Me, x = 2; R = 2,6-Me2, x = 2, 4, 12 3a-m). Increasing the length of the aliph. chain resulted in more sol. dicationic complexes. Photolytic demetalation of these diiron complexes provided an alternative route to the synthesis of terminal diphenoxyalkanes RC6H4O(CH2)xOC6H4R (same R, x 4a-m).