A new xantphos-type ligand and its gold(I) complexes: Synthesis, structure, luminescence

作者：Besenyei Gabor; Bitter Istvan; Parkanyi Laszlo; Szalontai Gabor; Baranyai Peter; Kunsagi Mate Eva; Faigl Ferenc; Gruen Alajos; Kubinyi Miklos^*

来源：Polyhedron, 2013, 55: 57-66.

DOI：10.1016/j.poly.2013.02.052

• Gold(I) complexes
• Phosphine ligands
• Coordination modes
• Crystal structure
• Luminescence

A novel xantphos analog diphosphine ligand, 9,9-dimethyl-4,5-bis(diphenylphosphinomethyl)-9H-xanthene (X(CP)(2)), with methylene groups inserted between the xanthene skeleton and the two diphenylphosphine units, has been synthesized. A two-coordinate and a three-coordinate gold(I) complex of the ligand, [Au2Cl2(X(CP)(2))] and [AuCl(X(CP)(2))], have been prepared and studied by X-ray diffraction, NMR and optical spectroscopy. In the solid state, [AuCl(X(CP)(2))] adopts a highly ordered structure with a planar xanthene skeleton that faces another plane composed of two phenyl rings and the AuCl moiety. The structure of [Au2Cl2(X(CP)(2))] is much less regular, the two P-Au-Cl vectors point to the opposite sides of the folded xanthene backbone. The exchange-broadened resonances in the NMR spectra of [AuCl(X(CP)(2)))] indicate that this complex exists as a mixture of various chemical species and/or conformers in solution. In contrast, the NMR spectra of [Au2Cl2(X(CP)(2))] exclude any medium-range exchange processes. Aurophilic interactions are absent in both X(CP)(2) complexes. X(CP)(2), as well as its two gold complexes, is phosphorescent in the solid state; the complexes emit at higher wavelengths and with longer lifetimes than the free ligand.

• 出版日期2013-5-17