Alteration of the aurophilic interactions in trimeric gold(I) compounds through charge transfer. Behavior of solvoluminescent Au(3)(MeN=COMe)(3) in the presence of electron acceptors.
The ability of the triangular gold(I) complex, Au(3)(MeN=COMe)(3), which as a solid displays the novel property of solvoluminescence (see: Vickery, J. C.; Olmstead, M. M.; Fung, E. Y.; Balch, A. L. Angew.Chem., Int. Ed. Engl. 1997, 36, 1179) to function as an electron donor has been demonstrated through spectroscopic studies and isolation of crystalline adducts with organic acceptor molecules. Four such adducts with nitro-9-fluorenones have been isolated and subject to single-crystal X-ray diffraction study. These are deep yellow [Au(3)(MeN=COMe)(3)].[2,4,7-trinitro-9-fluorenone], red [Au(3)(MeN=COMe)(3)].[2,4,5,7-tetranitro-9-fluorenone], red [Au(3)(MeN=COEt)(3)](2).[2,7-dinitro-9-fluorenone], and red [Au(3)(MeN=COEt)(3)](2).[2,4,7-trinitro-9-fluorenone]. The solid-state structures of [Au(3)(MeN=COMe)(3)].[2,4,7-trinitro-9-fluorenone] and [Au(3)(MeN=COMe)(3)].[2,4,5,7-tetranitro-9-fluorenone] consist of columns in which the planar gold(I) trimers and the nearly planar nitro-9-fluorenones are interleaved with the gold trimers making face-to-face contact with the nitroaromatic portion of the electron acceptor. Thus the organic acceptors disrupt the aurophilic interactions present in crystalline [Au(3)(MeN=COMe)(3)] itself. However, in [Au(3)(MeN=COEt)(3)](2).[2,7-dinitro-9-fluorenone] and [Au(3)(MeN=COEt)(3)](2).[2,4,7-trinitro-9-fluorenone], aurophilic interactions are found which produce dimers, [Au(3)(MeN=COEt)(3)](2), with nearly trigonal prismatic Au(6) cores. These dimers are interleaved with the nitro-9-fluorenone molecules to again form extended columns in which the components make face-to-face contact. Despite the fact that the gold atoms in [Au(3)(MeN=COMe)(3)] and [Au(3)(MeN=COEt)(3)] are in exposed sites and only two-coordinate, there is no evidence of additional coordination of the nitro-9-fluorenones with gold centers in the crystalline adducts.
Olmstead
M M
MM
Department of Chemistry, University of California, Davis, California 95616, USA.
Jiang
F
F
Attar
S
S
Balch
A L
AL