Structural studies of (2<i>R</i>,3<i>R</i>)-(+)-bis(diphenylphosphino)butane and (<i>R</i>)-(+)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl

Abstract The crystal structures of two chiral phosphanes, (( R,R )-chiraphos = (2 R ,3 R )-(+)-2,3-bis(diphenylphosphino)butane and R -Tol-BINAP = ( R )-(+)-2,2′-bis(di- p -tolylphosphino)-1,1′-binaphthyl) are unambiguously determined by X-ray crystallography and reported for the first time. The aim is to understand the structural characteristics and their chiral arrangement of the molecules. The ( R,R )-chiraphos structure was solved in the orthorhombic space group P 2 1 2 1 2 1 while R -Tol-BINAP was solved in the triclinic space group P 1. This set of compounds demonstrates attractive intramolecular phenyl ring interactions involving two terminal phenyl rings in ( R,R )-chiraphos, while a terminal tolyl ring and the central binaphthyl ring occurs in R -Tol-BINAP. The crystal structure analyses also revealed that all aromatic units have close C–H⋯aryl centroid weak contacts forming continuous networks of columns and layers in ( R , R )-chiraphos and R -Tol-BINAP respectively.