944709-04-0Relevant articles and documents
Unusual nitro-coordination of europium(iii) and terbium(iii) with pyridinyl ligands
De Bettencourt-Dias, Ana,Bauer, Sebastian,Viswanathan, Subha,Maull, Brandi C.,Ako, Ayuk M.
, p. 11212 - 11218 (2012/10/29)
A new ligand family based on picoline, bipyridine and terpyridine containing a nitro moiety has been synthesized and its coordination and sensitization ability for lanthanide ions has been studied. Three new complexes were characterized by X-ray single crystal diffraction and all three show uncommon coordination of the nitro moiety to the lanthanide ion. 5cTb, a terpyridine-nitro derivative with Tb(NO3)3, crystallizes in the orthorhombic space group Pbca with a = 15.125(3), b = 13.776(3), c = 18.716(4) A, and V = 3899.8(13) A3 and is isostructural with its Eu(iii) analog (5cEu) with cell parameters a = 15.1341(4), b = 13.7070(4), c = 18.8277(5) A. 6Eu, a tripodal amine with a nitro-derivatized pyridine with Eu(CF3SO3)3, crystallizes in the triclinic space group P1 with a = 11.067(2), b = 11.633(2), c = 12.772(3) A, α = 110.94(3), β = 97.49(3), γ = 91.42(3)° and V = 1518.1(5) A3. Finally, ligand 5a, a bipyridine-nitro derivative, crystallizes in the orthorhombic space group P21/n with a = 3.7128(3), b = 11.7806(8), c = 19.9856(14) A, β = 92.925(2)° and V = 873.01(11) A3. All four ligands show sensitization of Eu(iii) and Tb(iii) luminescence.
6,6″-azobis(2,2′-bipyridine) and its dinuclear ruthenium complex: A comparative study with positional isomers
Otsuki, Joe,Kurihara, Izumi,Imai, Arata,Hamada, Yuki,Omokawa, Nobuyuki
experimental part, p. 902 - 909 (2009/06/05)
The azobis(bipyridine) ligand 6,6″-azobis(2,2′-bipyridine) (6-azobpy) was prepared as a new member of the family of azopolypyridine derivatives. This compound undergoes reversible trans/cis photoisomerization. Reaction of 6-azobpy and [Ru(bpy)2Cl2] afforded a dinuclear complex [{Ru(bpy)2}2(μ-6-azobpy)] 4+. An analogue with deuterated bpy fragments was also prepared to help clarify the 1HNMR signals in the part of the 6-azobpy ligand. The analysis of 1H NMK spectra clearly identified the structure of the complex, in which the Ru2+ ions are chelated by the bpy parts of the bridging 6-azobpy ligand. Electronic absorption and electrochemical properties are characterized by the presence of a low-lying π level of the bridging ligand, manifested by a metal-to-ligand charge-transfer band extending down to 800 nm and by two consecutive one-electron reduction waves at relatively less negative potentials in cyclic voltammetry. These properties were compared with those of previously reported positional isomers with the help of density functional theory (DFT), time-dependent DFT, and Z1NDO calculations. The analysis of the redox couple of Ru3+/2+ showed that the redox potentials differ slightly between the diastereomers and that there is an intermetallic electronic interaction.
