Synthesis of [2]ferrocenophanes containing trivalent diphosphine units

► Two C5H4 rings of 1,1′-ferrocenylene are bridged with a P(III)-P(III) bond. ► The P-P bond was formed by Mg-mediated reductive coupling of [Fe{C5H4P(Cl)R}2]. ► M(CO)5 (M = Cr or W) was coordinated to the phosphorus center. ► Two stable conformations were found for diphospha[2]ferrocenophane.