210363-85-2Relevant academic research and scientific papers
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 role of isomeric effects on the luminescence lifetimes and electrochemistry of oligothienyl-bridged dinuclear tris(2,2′-bipyridine) ruthenium(II) complexes
Steen, Robert O.,Nurkkala, Lasse J.,Angus-Dunne, Sarah J.,Schmitt, Chantal X.,Constable, Edwin C.,Riley, Mark J.,Bernhardt, Paul V.,Dunne, Simon J.
experimental part, p. 1784 - 1794 (2009/02/08)
The luminescence lifetimes (in CH3CN at room temperature) and electrochemical potentials (in CH3CN) of a range of mono- and bis(bidentate) 2,2′-bipyridine-capped oligothiophene-bridged Ru II complexes based on the 6-(2-thienyl)-2,2′-bipyridine and 4-(2-thienyl)-2,2′-bipyridine motifs have been measured. The redox potentials occurred in a very narrow range and showed only small shifts from that of [Ru(bpy)3]2+, which indicates that the inductive effects of the substituents on the 2,2′-bipyridine ligands are very similar across this series. In the complexes that incorporated a bithiophene moiety the oxidation of the bithienyl group occurred at higher potentials than the metal-centered RuIII/II oxidation. No or very weak interaction between the metal cores in the dinuclear complexes was observed. It was found that the luminescence lifetimes of the complexes where the attachment point of the oligothiophene bridge is in the 4-position of a 2,2′-bipyridine ligand were extended compared to [Ru(bpy)3]2+, whereas the luminescence was very short-lived (30 ns) or completely quenched in the complexes where the oligothiophene bridge was attached in the 6-position. The difference in lifetimes is probably due to steric interactions between the thienyl bridge and the auxiliary bipyridyl ligands, resulting in disturbances in coordination symmetry of the metal core. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
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.
From 1,2,4-triazines and tributyl(ethynyl)tin to stannylated bi- and terpyridines: The cycloaddition pathway
Sauer, Juergen,Heldmann, Dieter K.,Pabst, Gunther R.
, p. 313 - 321 (2007/10/03)
Recently, we reported on cycloadditions between electron-deficient heterodienes and tributyl(ethynyl)tin, which provide a new pathway to stannylated pyridazines and, in one special case, pyridines. In order to broaden the synthetic scope of these reactions, we have developed hetero [4+2] cycloaddition reactions between a number of tailor-made 1,2,4-triazines 5-9 (acting as heterodienes), and tributyl(ethynyl)tin (acting as dienophile). The desired 1,2,4triazines are readily available, in moderate to very good yields, by the condensation reactions of appropiate carbamidrazones and glyoxals. These cycloadditions open up a novel route to regiospecifically stannylated 2,2'-bi- and 2,2',6',2''-terpyridines 1-4, 11 in good yields. The stannanes 1-4, 11 are versatile synthetic intermediates, and with this strategy various substituents can be incorporated directly by substitution of the stannyl group, as was shown for halogens and carbon electrophiles under Stille conditions.
