Hydride reduction of the cation [(η5-C5H5)Fe(Ph2PCH2CH2PPh2)CO]PF6; formation of (η5-C5H5)FeH(CO)(Ph2PCH2CH2PPh2) and elimination of H2 from [(η5-C5H5)FeH(CO)]2(Ph2PCH2CH2PPh2)