33354-77-7Relevant articles and documents
Chromium(VI) oxide-mediated oxidation of polyalkyl-polypyridines to polypyridine-polycarboxylic acids with periodic acid
Yamazaki, Shigekazu
supporting information, p. 2210 - 2218 (2019/06/25)
4,4′-Dicarboxy-2,2′-bipyridine was synthesized quantitatively by chromium(VI) oxide-mediated oxidation of 4,4′-dimethyl-2,2′-bipyridine or 4,4′-diethyl-2,2′-bipyridine with periodic acid as the terminal oxidant in sulfuric acid. 5,5′-Dicarboxy-2,2′-bipyridine and 6,6’-dicarboxy-2,2′-bipyridine were also synthesized by the method from the corresponding dimethyl bipyridines in excellent yields. 4,4′,4″-Tricarboxy-2,2′:6′,2″-terpyridine was obtained in 80% yield from 4,4′,4″-triethyl-2,2′:6′,2″-terpyridine, and 4,4′,4″,4′″-tetracarboxy-2,2′:6′,2″:6″,2′″-quaterpyridine was obtained in 72% yield from 4,4′,4″,4′″-tetraethyl-2,2′:6′,2″:6″,2′″-quaterpyridine by the same procedure.
A more efficient synthesis of 4,4′,4″-tricarboxy-2,2′: 6′,2″-terpyridine
Dehaudt, Jeremy,Husson, Jerome,Guyard, Laurent
scheme or table, p. 3337 - 3340 (2012/01/15)
We report in this paper a new route for the synthesis of 4,4′,4″-tricarboxy-2,2′:6′,2″-terpyridine. This synthetic pathway has a lower ecological impact with respect to yield, atom economy, solvent and chemicals used and wastes generated when compared to a previously reported method. In addition it uses furfural, which can be obtained from renewable sources. The title compound can be used to prepare complexes that are valuable for applications in Dye Sensitized Solar Cells.
Engineering of efficient panchromatic sensitizers for nanocrystalline TiO2-based solar cells
Nazeeruddin,Pechy,Renouard,Zakeeruddin,Humphry-Baker,Cointe,Liska,Cevey,Costa,Shklover,Spiccia,Deacon,Bignozzi,Graetzel
, p. 1613 - 1624 (2007/10/03)
A new series of panchromatic ruthenium(II) sensitizers derived from carboxylated terpyridyl complexes of tris-thiocyanato Ru(II) have been developed. Black dye containing different degrees of protonation {(C2H5)3NH}[Ru(H3tcterpy)(NCS) 3] 1, {(C4H9)4N}2[Ru(H2 tcterpy)(NCS)3] 2, {(C4H9)4N}3[Ru(Htcterpy)(NCS) 3] 3, and {(C4H9)4N}4[Ru(tcterpy)(NCS) 3] 4 (tcterpy = 4,4′,4″-tricarboxy-2,2′:6′,2″-terpyridine) have been synthesized and fully characterized by UV-vis, emission. IR, Raman, NMR, cyclic voltammetry, and X-ray diffraction studies. The crystal structure of complex 2 confirms the presence of a RuIIN6 central core derived from the terpyridine ligand and three N-bonded thiocyanates. Intermolecular H-bonding between carboxylates on neighboring terpyridines gives rise to 2-D H-bonded arrays. The absorption and emission maxima of the black dye show a bathochromic shift with decreasing pH and exhibit pH-dependent excited-state lifetimes. The red-shift of the emission maxima is due to better π-acceptor properties of the acid form that lowers the energy of the CT excited state. The low-energy metal-to-ligand charge-transfer absorption band showed marked solvatochromism due to the presence of thiocyanate ligands. The Ru(II)/(III) oxidation potential of the black dye and the ligand-based reduction potential shifted cathodically with decreasing number of protons and showed more reversible character. The adsorption of complex 3 from methoxyacetonitrile solution onto transparent TiO2 films was interpreted by a Langmuir isotherm yielding an adsorption equilibrium constant, Kads, of (1.0 ± 0.3) × 105 M-1. The amount of dye adsorbed at monolayer saturation was (na = 6.9 ± 0.3) × 10-8 mol/mg of TiO2, which is around 30% less than that of the cis-di(thiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium(II) complex. The black dye, when anchored to nanocrystalline TiO2 films achieves very efficient sensitization over the whole visible range extending into the near-IR region up to 920 nm, yielding over 80% incident photon-to-current efficiencies (IPCE). Solar cells containing the black dye were subjected to analysis by a photovoltaic calibration laboratory (NREL, U.S.A.) to determine their solar-to-electric conversion efficiency under standard AM 1.5 sunlight. A short circuit photocurrent density obtained was 20.5 mA/cm2, and the open circuit voltage was 0.72 V corresponding to an overall conversion efficiency of 10.4%.
