title: Orange and yellow crystals of copper(I) complexes bearing 8-(diphenylphosphino)quinoline: a pair of distortion isomers of an intrinsic tetrahedral complex.
abstract: The tetrafluoroborate salt of bis{8-(diphenylphosphino)quinoline}copper(I), [Cu(Ph(2)Pqn)(2)]BF(4), afforded orange prismatic (2O) or yellow columnar (2Y) crystals, dependent on the solvent and concentration of the recrystallization solution used. X-ray analysis revealed that crystals of 2O and 2Y had the same composition and exhibited different crystal systems: 2O was triclinic, with space group P ̅1 and Z = 2, and 2Y was monoclinic with space group P2(1)/c and Z = 4. In these crystals, the tetrahedral copper(I) complex exhibited a strong "rocking distortion" toward a trigonal pyramidal coordination geometry (by a slide translation of one of the unsymmetrical bidentate chelating ligands along the tetrahedral edge). In addition, both the 2O and 2Y complexes showed a "flattening distortion", meaning that the dihedral angle between the two chelate planes were off-perpendicular and oriented toward opposite directions, which resulted in a pair of distortion isomers: syn clinal (sc: 2O) and anti clinal (ac: 2Y). (31)P CP-MAS NMR spectroscopy indicated that 2O and 2Y could be distinguished. Both isomers exhibited inequivalent P atoms, but a larger difference in chemical shift was observed in 2Y. TD-DFT calculations reproduced the difference in spectra between the orange- and yellow-colored complexes, which originated from metal-to-ligand charge-transfer transitions.
authors: Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan. suzuki@cc.okayama-u.ac.jp
authors: Takayoshi
authors: T
authors: Suzuki
authors: Hiroshi
authors: H
authors: Yamaguchi
authors: Akira
authors: A
authors: Hashimoto
authors: Koichi
authors: K
authors: Nozaki
authors: Mototsugu
authors: M
authors: Doi
authors: Naoya
authors: N
authors: Inazumi
authors: Noriaki
authors: N
authors: Ikeda
authors: Satoshi
authors: S
authors: Kawata
authors: Masaaki
authors: M
authors: Kojima
authors: Hideo D
authors: HD
authors: Takagi