X-ray comparison of the molecular structures of 4a-methyl-1,3,9-triphenyl-4a-H-fluorene and its Fe(CO)3 complex

Synthesis of Bis(trityl)iron(II) and Formation of the Iron(0)-Stabilized o,o-Isomer of Gomberg’s Dimer

“…To account for the formation of 2 , we suggest that thermolysis of 1 in the presence of P­(OMe) 3 results in loss of a trityl radical and formation of the Fe­(I) piano-stool complex [(η 5 -CPh 3 )­Fe I (P­(OMe) 3 ) 3 ]. This intermediate can then dimerize to form complex 2 , a transformation that is driven by the formation of an energetically favorable Fe(0)−η 4 -butadiene interaction. ,− We propose that this Fe­(I) intermediate can also lose a Me radical, forming an Fe­(II) phosphonate, [(η 5 -CPh 3 )­Fe II (P­(OMe) 3 ) 2 (P­(O)­(OMe) 2 )], which serves as a precursor to 3 . Similar reactivity has been reported for [CpCr­(CO) 3 ] 2 and [CpRu­(CO) 2 ] 2 , − although in our case we do not know the fate of the Me group.…”