132020-95-2Relevant academic research and scientific papers
Arsenic(III), Antimony(III), and Bismuth(III) Trihalide Complexes of Paracyclophane: From Weak van der Waals Coordination to Strongly Directional ? Complexation with Single or Double External η6 Coordination
Probst, Thomas,Steigelmann, Oliver,Riede, Juergen,Schmidbaur, Hubert
, p. 1089 - 1094 (2007/10/02)
Paracyclophane forms the adducts C24H24 x AsCl3 (1), C24H24 x (SbCl3)2 x 1/2 C6H6 (2), and C24H24 x (BiCl3)3 x C6H6 (3).For solutions in polar solvents NMR spectra indicate extensive dissociation and/ or fluxionality.In the crystals adduct 1 features a weak addition of the AsCl3 molecule to one open side of a paracyclophane molecule with long intermolecular contacts approaching C3vsymmetry. - Crystalline 2 shows SbCl3coordination to two of the benzene rings of the hydrocarbon in a quasi-centered η6 mode, while one of the benzene rings remains uncoordinated.Chlorine-bridging between antimony atoms leads to tetrameric units (SbCl3)4 in the lattice. - In the bismuth compound 3 each benzene ring of the hydrocarbon is engaged in centroid (η6)? complexation, with the BiCl3 units crosslinked by chlorine bridges.The average of the Bi-ring distances (3.08, 2.98, and 2.99 Angstroem) is shorter than for the Sb-ring distances in 2 (3.047 and 3.050 Angstroem), indicating stronger bonding.The crystal benzene is not coordinating.Key Words: Paracyclophane ligand / (η6)? Complexes / Arsenic(III) complexes / Antimony(III) complexes / Bismuth(III) complexes
