210363-85-2Relevant articles and documents
The intramolecular aryl embrace: From light emission to light absorption
Bozic-Weber, Biljana,Constable, Edwin C.,Housecroft, Catherine E.,Kopecky, Peter,Neuburger, Markus,Zampese, Jennifer A.
experimental part, p. 12584 - 12594 (2012/01/06)
6-(1-Methylpyrrol-2-yl)-2,2′-bipyridine, 3, and 6-(selenophene-2-yl)- 2,2′-bipyridine, 4, have been prepared and characterized in solution and by structural determinations. Copper(i) complexes [CuL2][PF 6] in which L is 2,2′-bipyridine substituted in the 6-position by furyl, thienyl, N-methylpyrrolyl, selenopheneyl, methyl or phenyl, (L = 1-6) have been synthesized. The complexes have been characterized by electrospray mass spectrometry, and solution NMR and UV-VIS spectroscopies. The single crystal structures of [Cu(1)2][PF6], [Cu(2) 2][PF6], [Cu(3)2][PF6], [Cu(5) 2][PF6] and [Cu(6)2][PF6] have been determined. In those compounds containing an aromatic substituent attached to the bpy unit, the substituent is twisted with respect to the latter. In [Cu(3)2][PF6] and [Cu(5)2][PF6], this results in intra-cation π-stacking between ligands which is very efficient in [Cu(3)2]+ despite the steric requirements of the N-methyl substituents. Face-to-face stacking between the ligands in the [Cu(2)2]+ ion is achieved by complementary substituent twisting and elongation of one Cu-N bond, but there is no analogous intra-cation π-stacking in [Cu(1)2]+. Ligand exchange reactions between [CuL2][PF6] (L = 1-6) and TiO2-anchored ligands 7-10 (L′ = 2,2′-bipyridine-based ligands with CO 2H or PO(OH)2 anchoring groups) have been applied to produce 24 surface-anchored heteroleptic copper(i) complexes, the formation of which has been evidenced by using MALDI-TOF mass spectrometry and thin layer solid state diffuse reflectance electronic absorption spectroscopy. The efficiencies of the complexes as dyes in DSCs have been measured, and the best efficiencies are observed for [CuLL′] with L′ = 10 which contains phosphonate anchoring groups. The Royal Society of Chemistry.
The effects of pendant vs. fused thiophene attachment upon the luminescence lifetimes and electrochemistry of tris(2,2′-bipyridine)ruthenium(II) complexes
Nurkkala, Lasse J.,Steen, Robert O.,Friberg, Henrik K. J.,Haeggstroem, Johanna A.,Bernhardt, Paul V.,Riley, Mark J.,Dunne, Simon J.
experimental part, p. 4101 - 4110 (2009/02/07)
The electrochemical and photophysical properties for a range of tris(2,2′-bipyridine)ruthenium(II) complexes in which a thiophene substituent is attached to one of the bipyridine ligands by either a pendant or a fused mode have been determined. The fused mode of attachment eliminates torsional movement between the thiophene unit and the chelating bipyridine, thereby offering optimal overlap between the ?-systems of the chelating unit and the attached thiophene unit. The electrochemical properties of these complexes were found to be similar; however, the luminescence lifetimes and intensities (in CH3CN at room temperature) were found to be correlated to the mode of attachment. The longest luminescence lifetime was observed for the complex [Ru(bpy)2{4-(thiophen-2-yl)-2,2′-bipyridine}] 2+ (3000 ns), as compared to the prototypic [Ru(bpy) 3]2+ (1745 ns). This complex also had the highest quantum yield (0.045). In the four isomeric complexes, where the thiophene ring was fused to the b or c face of the pyridine ring, the lifetimes fell in the interval 275-1510 ns, and the quantum yield ranged between 0.0047 and 0.014. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.