Crystal structure of bis{(S)-1-[2-(diphenylphosphanyl)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 monosolvate 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 . 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.

Keywords

• crystal structure
• ferrocene
• PNP ligand
• hydrogen bonding