1762-42-1Relevant articles and documents
Threading of various 'U' shaped bidentate axles into a heteroditopic macrocyclic wheel: Via NiII/CuII templation
Nandi, Mandira,Santra, Saikat,Akhuli, Bidyut,Ghosh, Pradyut
, p. 7421 - 7433 (2017)
The threading of 'U' shaped bent axles having diverse functionalities (Axle1-Axle10) is investigated by using a heteroditopic amido-amine macrocyclic (MC) wheel via NiII or CuII metal ion templation. These bent shaped axles are the derivatives of 4,4′-substituted 2,2′-bipyridine, which are composed of various terminal groups like alkene, alkyne, bromide, hydroxyl and azide. Such metallo [2]pseudorotaxanes are well characterised by ESI-MS, EPR and FT-IR spectroscopic studies, UV-Vis absorption studies, elemental analysis and single-crystal X-ray diffraction studies wherever possible. Experimental evidence supports 1:1:1 ternary complexation between MC, the metal ion and axle. The single crystal X-ray structures of three CuII templated ternary complexes (PR1′, PR3′ and PR7′) show the penta-coordination arrangement around the templating metal ion. Interestingly, judicious selection of chemical functionalities in the complementary wheel and axle components enables to show the existence of various covalent and non-covalent interactions.
Synthetic routes to ruthenium(II) species containing carboxylate-functionalized 2,2′-bipyridine ligands
Patterson, Bradley T.,Keene, F. Richard
, p. 999 - 1002 (1998)
Two methods are reported for the incorporation of carboxylate substituents on polypyridyl ligands coordinated to ruthenium(II) centres. In the first, a precursor complex is synthesized with ethoxycarbonyl groups which are subsequently base-hydrolysed to produce the carboxylate in high yield (-CO2Et → -CO2H). In the second method, ruthenyl (RuIV=O) species were used to chemically catalyse the electochemical oxidation of methyl substituents on the ligands of a precursor complex to produce the target carboxylate species (-CH3 → -CO2H).
Selective Photoinactivation of Methicillin-Resistant Staphylococcus aureus by Highly Positively Charged RuII Complexes
Feng, Yang,Sun, Wei-Ze,Wang, Xue-Song,Zhou, Qian-Xiong
, p. 13879 - 13884 (2019)
Ruthenium(II) polypyridyl complexes featuring peripheral quaternary ammonium structures were found to be able to selectively inactivate Gram-positive Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA) upon visible light irradiation, but have low phototoxicity toward 293T cells, L02 cells and lack hemolysis toward rabbit red blood cells (RBC), exhibiting promising potential as a novel type of antimicrobial photodynamic therapy (aPDT) agents.
Dye molecular structure device open-circuit voltage correlation in Ru(II) sensitizers with heteroleptic tridentate chelates for dye-sensitized solar cells
Wu, Kuan-Lin,Li, Cheng-Hsuan,Chi, Yun,Clifford, John N.,Cabau, Lydia,Palomares, Emilio,Cheng, Yi-Ming,Pan, Hsiao-An,Chou, Pi-Tai
, p. 7488 - 7496 (2012)
Dicarboxyterpyridine chelates with π-conjugated pendant groups attached at the 5- or 6-position of the terminal pyridyl unit were synthesized. Together with 2,6-bis(5-pyrazolyl)pyridine, these were used successfully to prepare a series of novel heteroleptic, bis-tridentate Ru(II) sensitizers, denoted as TF-11-14. These dyes show excellent performance in dye-sensitized solar cells (DSCs) under AM1.5G simulated sunlight at a light intensity of 100 mW cm -2 in comparison with a reference device containing [Ru(Htctpy)(NCS)3][TBA]3 (N749), where H3tctpy and TBA are 4,4′,4″-tricarboxy-2,2′:6′,2″- terpyridine and tetra-n-butylammonium cation, respectively. In particular, the sensitizer TF-12 gave a short-circuit photocurrent of 19.0 mA cm-2, an open-circuit voltage (VOC) of 0.71 V, and a fill factor of 0.68, affording an overall conversion efficiency of 9.21%. The increased conjugation conferred to the TF dyes by the addition of the π-conjugated pendant groups increases both their light-harvesting and photovoltaic energy conversion capability in comparison with N749. Detailed recombination processes in these devices were probed by various spectroscopic and dynamics measurements, and a clear correlation between the device VOC and the cell electron lifetime was established. In agreement with several other recent studies, the results demonstrate that high efficiencies can also be achieved with Ru(II) sensitizers that do not contain thiocyanate ancillaries. This bis-tridentate, dual-carboxy anchor configuration thus serves as a prototype for future omnibearing design of highly efficient Ru(II) sensitizers suited for use in DSCs.
Two-dimensional emission quenching and charge separation using a Ru(II)-photosensitizer assembled with membrane-bound acceptors
Hammarstrom,Norrby,Stenhagen,Martensson,Akermark,Almgren
, p. 7494 - 7504 (1997)
Novel syntheses of the bipyridine ligand 1, dcHb (dcHb = 4,4′-dicarboxy-2,2′-bipyridine), by anionic oxidation of 4,4′-dimethyl-2′,2-bipyridine (dmb) using molecular oxygen (4 atm), and of the sensitizer precursor 4, tris(4,4′-diethoxycarbonyl-2,2′-bipyridine)ruthenium(II) bis(triflate), from a chloride-free Ru(II) precursor 3b, RuII(DMSO)4(triflate)2-n(EtOH)n (n = 0-2, DMSO = dimethyl sulfoxide, triflate = OSO2CF3) are reported. The anionic sensitizer Ru(dcb)34- (5) was shown to bind to vesicles of lecithin when these were made positively charged by cationic bipyridinium electron acceptors. With cetylmethylviologen (CMV2+) as quencher, the time-resolved decay of the Ru(dcb)34- emission followed a model for diffusion-controlled quenching in two dimensions. However, the diffusion coefficient obtained from a fit to the data was very small, (6±2)×10-11 m2 s-1, comparable to values for amphiphiles in bilayers, even though Ru(dcb)34- diffuses in the water region at the vesicle surface. The quantum yield of primary charge separation was 0.06±0.02, which is significant, if not high, despite the large electrostatic attraction between the reactants. Attempts were made to increase the charge separation yield by the use of a monocationic acceptor. Possible extensions of the system are discussed, such as charge separation across the vesicle membrane and the covalent linking of a donor to the sensitizer.
A panchromatic, near infrared Ir(III) emitter bearing a tripodal C^N^C ligand as a dye for dye-sensitized solar cells
Hierlinger, Claus,Flint, Heather V.,Cordes, David B.,Slawin, Alexandra M.Z.,Gibson, Elizabeth A.,Jacquemin, Denis,Guerchais, Véronique,Zysman-Colman, Eli
, p. 109 - 115 (2018)
The synthesis of a new complex of the form [Ir(C^N^C)(N^N)Cl] [where C^N^C = 2-(bis(4-(tert-butyl)phenyl)methyl)pyridinato (dtBubnpy, L1) and N^N is diethyl [2,2′-bipyridine-4,4′-dicarboxylate (deeb)] is reported. The crystal structure reveals an unusual tripodal tridentate C^N^C ligand forming three six-membered rings around the iridium center. The photophysical and electrochemical properties suggest the use of this complex as a dye in dye-sensitized solar cells. Time-Dependent Density Functional Theory (TD-DFT) calculations have been used to reveal the nature of the excited-states.
Photo-induced electron transfer study of rhenium(I) bipyridyl complexes with covalently linked phenothiazine donor through different bridge
Sun, Shiguo,Shi, Lei,Liu, Fengyu,Fan, Jiangli,Peng, Xiaojun
, p. 171 - 177 (2010)
A novel rhenium(I) bipyridyl complex 1a, [(4,4'-di-COOEt-bpy)Re(CO)3(py-NHCO-PTZ)PF6] and a model 1b, [(4,4'-di-COOEt-bpy)Re(CO)3(py-PTZ)PF6] (bpy is 2, 2'-bipyridine, py-NHCO-PTZ is phenothiazine-(10-carbonyl amide) pyridine and py-PTZ is 10-(4-picolyl) phenothiazine) were synthesized. Their photo-induced electron transfer (ET) reaction with electron acceptor methyl viologen (MV2+) in acetonitrile was studied by nanosecond laser flash photolysis at room temperature. Photoexcitation of 1 in the presence of MV2+ led to ET from the Re moiety to MV2+ generating Re(II) and methyl viologen radical (MV·+). Then Re(II) was reduced either by the charge recombination with MV·+ or by intramolecular ET from the attached PTZ, regenerating the photosensitizer Re(I) and forming the PTZ radical at 510 nm. In the case of 1b, the absorption for PTZ radical can be observed distinctly accompanied intermolecular ET, whereas not much difference at 510 nm can be detected for 1a on the time scale of the experiments. This demonstrates that the linking bridge plays a key role on the intramolecular ET in complex 1.
Control of Excited-State Supramolecular Assembly Leading to Halide Photorelease
Turlington, Michael D.,Troian-Gautier, Ludovic,Sampaio, Renato N.,Beauvilliers, Evan E.,Meyer, Gerald J.
, p. 3316 - 3328 (2019/05/25)
Ground- and excited-state control of halide supramolecular assembly was achieved through the preparation of a series of ester- and amide-functionalized ruthenium polypyridyl complexes in CH2Cl2. Hydrogen-bonding amide and alcohol groups on the receptor ligand were found to direct interactions with halide, while halide association with the ethyl ester groups was not observed. The various functional groups on the receptor ligands tuned the ground-state equilibrium constants over 2 orders of magnitude (1 × 105 to 1 × 107 M-1), and the fractional contribution of each hydrogen-bond donor to the total equilibrium constant was determined. Pulsed-laser excitation of the complexes resulted in excited-state localization on the ester- or amide-functionalized ligands. In the case where the excited state was oriented toward an associated halide ion (the amide complexes), an 80 ± 10 meV Coulombic repulsion was induced that lowered the excited-state equilibrium constant (K?eq) and resulted in halide photorelease. The rate constants for excited-state halide release (k?21) were determined, and the values varied based on the functional groups present in the receptor ligand. Complexes with more hydrogen-bonding donors had smaller rate constants for halide photorelease. In a complex without a specific receptor ligand, the excited-state dipole was not oriented toward the associated halide, and the excited state was therefore found to have a larger equilibrium constant for halide association than the ground state.
