Orange and Yellow Crystals of Copper(I) Complexes Bearing 8-(Diphenylphosphino)quinoline: A Pair of Distortion Isomers of an Intrinsic Tetrahedral Complex
2011; American Chemical Society; Volume: 50; Issue: 9 Linguagem: Inglês
10.1021/ic1024636
ISSN1520-510X
AutoresTakayoshi Suzuki, Hiroshi Yamaguchi, Akira Hashimoto, Koichi Nozaki, Mototsugu Doi, Naoya Inazumi, Noriaki Ikeda, Satoshi Kawata, Masaaki Kojima, Hideo D. Takagi,
Tópico(s)Crystallography and molecular interactions
ResumoThe 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.
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