Crystal structure of bis{(S)-1-[2-(diphenylphosphan- yl)ferrocenyl]-(R )-ethyl}ammonium bromide dichloromethane monosolvate

Abstract

During the synthesis of an FeBr₂ complex with the PNP ligand (R,R,SFc,SFc)-[Fe₂(C₅H₅)₂(C₃₈H₃₅NP₂)] (1), single crystals of the dichloromethane mono-solvate of the Br salt of the protonated ligand 1H+ were obtained serendipitously, i.e. [Fe₂(C₅H₅)₂(C₃₈H₃₆NP₂)]Br CH₂Cl₂. The crystal structure of 1H Br -CH₂Cl₂ was determined by single-crystal X-ray diffraction. The mean bond lengths in the ferrocene units are Fe-C = 2.049 (3) Å and C-C = 1.422 (4) Å within the cyclopentadienyl rings. The mean C-N bond length is 1.523 (4) Å. The interplanar angle between the two connected cyclopentadienyl rings is 49.2 (2) . One ferrocene moiety adopts a staggered conformation, whereas the other is between staggered and eclipsed. The Br ions and the CH₂Cl₂ molecules are located in channels extending along <100>. One ammonium H atom forms a hydrogen bond with the Br ion [H Br = 2.32 (4) Å and C-H Br = 172 (3) ]. The second ammonium H atom is not involved in hydrogen bonding.