Structural, Photophysical, and Catalytic Properties of Au(I) Complexes with 4-Substituted Pyridines

• Published in: Inorganic chemistry 2008-04, Vol.47 (7), p.2543-2551
• Main Authors: Lin, J. C. Y, Tang, S. S, Vasam, C. Sekhar, You, W. C, Ho, T. W, Huang, C. H, Sun, B. J, Huang, C. Y, Lee, C. S, Hwang, W. S, Chang, A. H. H, Lin, Ivan J. B
• Format: Article
• Language: English
• Subjects: Agglomeration; Catalysts; Cationic; Density functional theory; Diffraction; Ligands; Mathematical analysis; Pyridines
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic701872f

Ionic gold(I) complexes with general formula of [Au(Py)2][AuCl2] and [Au(Py)2][PF6] (Py = 4-substituted pyridines) have been synthesized. Structures of five Au(I) complexes and a Ag(I) complex were determined by single crystal X-ray diffraction. Evidence for cationic aggregation of [Au(py)2][PF6] complexes in solution was obtained by conductivity measurements and by the isosbestic point observed from variable temperature UV–visible absorption spectra. All compounds were luminous in the solid state. Calculations employing density functional theory were performed to shed light on the nature of the electronic transitions. While the [Au(4-dmapy)2][AuCl2] (4-dmapy = 4-dimethylaminopyridine) and [Au(4-pic)2][AuCl2] (4-pic = 4-picoline) emissions were found to be mainly ligand in nature, their [PF6]− counterparts involved a Au···Au-interaction imbedded in the highest occupied molecular orbital. [Au(4-dmapy)2][AuCl2] was found to be an efficient catalyst for Suzuki cross-coupling of aryl bromide and phenylboronic acid.