Alteration of the aurophilic interactions in trimeric gold(I) compounds through charge transfer.: Behavior of solvoluminescent Au3(MeN=COMe)3 in the presence of electron accepters

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)}. {2,3,7-trinitro-9-fluorenone}, red {Au-3(MeN=COMe)(3)}. {2,4,5,7-tetranitro-9-fluorenone), red {Au-3(MeN=COEt)(3)}. {2,7-dinitro-9-fluorenoe}, and red {Au-3(MeN=COMe)(3)). {2,4,7-tetranitro-9-fluorenone}. The solid-state structures of {Au-3(MeN=COMe)(3)}. {2,4,7-tetranitro-9-fluorenone} and (Au3(MeN=COMe)3) (2,4,5,7-teuanitro-9-flu 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 accepters 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.