Synthesis of 1,1‘-Ferrocenylene-Bridged Bisdiphosphenes

A simple synthetic access to the first ferrocenylene-bridged bisdiphosphenes Fe(C5H4−PP−R)2 is reported. The unsaturated PP units require steric protection by adjacent substituents such as Dmp (2,6-dimesitylphenyl) and Tbt (2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) and should be capable of conjugative interaction with the central metallocene unit. The electronic situation in these molecules has been assessed on the basis of DFT calculations. As a derivative of the Tbt-substituted bisdiphosphene with Tbt-PH2, the resulting ferrocenylene-bridged bis-1,3-dihydrotriphosphane has been characterized by X-ray crystallography