Phosphine-triggered co-catenation of :BR and CO on an iron atom.

The chain gang: By treatment of an iron bis(borylene) complex with PCy3 and subsequent stepwise substitution of a CO ligand by PMe3 , a catenated 1D OC-B-B-CO chain was generated in the coordination sphere of iron. This is an CO analogue of the recently reported 1D B-B-B-B chain in the iron tetraboron complex [(OC)2Fe{BN(SiMe3)2}2(BDur)2]. Dur=2,3,5,6-tetramethylphenyl.