The effect of gold(i) coordination on the dual fluorescence of 4-(dimethylamino)pyridine
- López-De-Luzuriaga, J.M. 1
- Manso, E. 1
- Monge, M. 1
- Olmos, M.E. 1
- Rodríguez-Castillo, M. 1
- Sampedro, D. 1
-
1
Universidad de La Rioja
info
ISSN: 1477-9226
Año de publicación: 2015
Volumen: 44
Número: 24
Páginas: 11029-11039
Tipo: Artículo
Otras publicaciones en: Dalton Transactions
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Resumen
The reactions of 4(dimethylamino)pyridine (DMAP) with the gold(i) precursors [AuR(tht)] (R = C<inf>6</inf>F<inf>5</inf>, C<inf>6</inf>Cl<inf>2</inf>F<inf>3</inf> or C<inf>6</inf>Cl<inf>5</inf>; tht = tetrahydrothiophene) lead to complexes [AuR(DMAP)] (R = C<inf>6</inf>F<inf>5</inf> (1), C<inf>6</inf>Cl<inf>2</inf>F<inf>3</inf> (2) or C<inf>6</inf>Cl<inf>5</inf> (3)). X-ray diffraction studies of the complexes reveal the presence of discrete molecules in which aurophilic contacts are absent, with π-stacking (1) or hydrogen bond (2) interactions being responsible for the supramolecular arrangements found in the solid state. All complexes display fluorescence in solution in solvents of different polarities such as toluene, chloroform or acetonitrile. In all cases the emission energy is similar to the low-energy Twisted Intramolecular Charge Transfer (TICT) emission of free DMAP. TDDFT calculations confirm that the fluorescence of complexes 1-3 arises from the ICT excited state of bonded DMAP in which a 90°distortion of the pyridine ring and -NMe<inf>2</inf> planes is observed. Model calculations based on experimental parameters show a higher degree of polarization of DMAP upon coordination to Au(i) organometallic fragments. This journal is © The Royal Society of Chemistry.