A Rapid General Synthesis and the Spectroscopic Data of 2,2′-Bis-(Di-Isopropylphosphino)-1,1′-Dibromoferrocene, (bpdbf), 1,1′, 2,2′-Tetrakis-(Di-Isopropylphosphino) Ferrocene, (tdipf) and Related Ligands. Taking dppf into the Future

The clean high yielding, synthesis and structure of the tetraphosphine ligand, 1,1´,2,2´-tetrakis-(di-isopropyl-phosphino)ferrocene, (tdipf), is described. In addition, an improved synthesis of the 1,1´,2,2´-tetrakis(diphenylphosphino)ferrocene, (tppf) and 2,2´-bis-(diphenylphosphino)-1,1´-dibromoferrocene are also reported and the synthetic method is generalised to include the synthesis of 3,3’-bis-(diphenylphosphino)-1,1´,2,2´-tetrabromoferrocene. The related ligands 2,2´-bis-(iso-propylphosphino)-1,1´-bis-diphenylphosphinoferrocene (diprdppf) and 2,2´-bis-(di-isopropylphosphino)-dibromoferrocene have also been prepared and characterised. The crystal structure of the square planar bimetallic nickel (II) dichloride of tdipf is also described, together with a brief NMR study investigating the synthesis of this and related metal complexes. The crystal structures of the palladium and platinum dichloride complexes of 2,2’-bis-(di-isopropylphosphino)-1,1’-dibromoferrocene, bpdbf, are also discussed in the context of comparison with previously known crystal structures in the same general family. A general discussion on the synthetic methodology is given and pointers to future research other researchers might explore.