71022-75-8Relevant articles and documents
Non-centrosymmetric packing of 1-D coordination networks based on chirality
Jouaiti, Abdelaziz,Hosseini, Mir Wais,Kyritsakas, Nathalie
, p. 1898 - 1899 (2002)
Using CoCl2 and a chiral tecton possessing C2 chirality and based on two coordination poles composed of a pyridine unit connected at the 4-position to a pyridine bearing at the 2 and 6 positions two optically active oxazoline moieties, a polar solid is obtained. The latter results from the acentric packing of directional 1-D coordination networks.
G-quadruplex DNA as a molecular target for induced synthetic lethality in cancer cells
McLuckie, Keith I. E.,Di Antonio, Marco,Zecchini, Heather,Xian, Jian,Caldas, Carlos,Krippendorff, Ben-Fillippo,Tannahill, David,Lowe, Christopher,Balasubramanian, Shankar
, p. 9640 - 9643 (2013)
Synthetic lethality is a genetic concept in which cell death is induced by the combination of mutations in two sensitive genes, while mutation of either gene alone is not sufficient to affect cell survival. Synthetic lethality can also be achieved "chemically" by combination of drug-like molecules targeting distinct but cooperative pathways. Previously, we reported that the small molecule pyridostatin (PDS) stabilizes G-quadruplexes (G4s) in cells and elicits a DNA damage response by causing the formation of DNA double strand breaks (DSB). Cell death mediated by ligand-induced G4 stabilization can be potentiated in cells deficient in DNA damage repair genes. Here, we demonstrate that PDS acts synergistically both with NU7441, an inhibitor of the DNA-PK kinase crucial for nonhomologous end joining repair of DNA DSBs, and BRCA2-deficient cells that are genetically impaired in homologous recombination-mediated DSB repair. G4 targeting ligands have potential as cancer therapeutic agents, acting synergistically with inhibition or mutation of the DNA damage repair machinery.
A water-soluble Pybox derivative and its highly luminescent lanthanide ion complexes
De Bettencourt-Dias, Ana,Barber, Patrick S.,Bauer, Sebastian
, p. 6987 - 6994 (2012)
A new water-soluble Pybox ligand, 1, has been synthesized and found to crystallize in the monoclinic P21/n space group with unit cell parameters a = 6.0936(1) A, b = 20.5265(4) A, c = 12.0548(2) A, and β = 90.614(1)°. In the crystal, a water molecule is bound through hydrogen-bonding interactions to the nitrogen atoms of the oxazoline rings. This ligand was used to complex a variety of lanthanide ions, opening up new avenues for luminescence and catalysis in aqueous environment. These complexes are highly luminescent in aqueous solutions, in acetonitrile, and in the solid state. Aqueous quantum yields are high at 30.4% for Eu(III), 26.4% for Tb(III), 0.32% for Yb(III), and 0.11% for Nd(III). Er(III) did not luminesce in water, but an emission efficiency of 0.20% could be measured in D2O. Aqueous emission lifetimes were also determined for the visible emitting lanthanide ions and are 1.61 ms for Eu(III) and 1.78 ms for Tb(III). Comparing emission lifetimes in deuterated and nondeuterated water indicates that no water molecules are coordinated to the metal ion. Speciation studies show that three species form successively in solution and the log β values are 5.3, 9.6, and 13.8 for Eu(III) and 5.3, 9.2, and 12.7 for Tb(III) for 1:1, 2:1, and 3:1 ligand to metal ratios, respectively.
Luminescent Carbazole-Based EuIII and YbIII Complexes with a High Two-Photon Absorption Cross-Section Enable Viscosity Sensing in the Visible and near IR with One- And Two-Photon Excitation
De Bettencourt-Dias, Ana,Fetto, Natalie R.,Monteiro, Jorge H. S. K.,Tucker, Matthew J.
supporting information, p. 3193 - 3199 (2020/03/19)
The newly synthesized EuIII and YbIII complexes with the new carbazole-based ligands CPAD2- and CPAP4- display the characteristic long-lived metal-centered emission upon one- and two-photon excitation. The EuIII complexes show the expected narrow emission bands in the red region, with emission lifetimes between 0.382 and 1.464 ms and quantum yields between 2.7% and 35.8%, while the YbIII complexes show the expected emission in the NIR region, with emission lifetimes between 0.52 and 37.86 μs and quantum yields between 0.028% and 1.12%. Two-photon absorption cross sections (σ2PA) as high as 857 GM were measured for the two ligands. The complexes showed a strong dependence of the one- and two-photon sensitized emission intensity on solvent viscosity in the range of 0.5-200 cP in the visible and NIR region.
Heavy metal complexes of 4-chlorodipicolinic acid - structural, spectral and thermal correlations
Vargová,Almá?i,Gyepes,Vetráková
, p. 3013 - 3029 (2019/11/11)
The ligand, 4-chloro-2,6-dipicolinic acid (H2PDA-Cl), and its two heavy metal complexes, [Ag(HDPA-Cl)(H2DPA-Cl)·2H2O] (1) and {[Cd(μ2-H2O)(H2O)(PDA-Cl)]}n (2), were prepared and then characterized by single-crystal X-ray diffraction. In addition, spectral and thermal correlations with structural results complete their solid-state description and facilitate complex 3 ([Pb(DPA-Cl)]) composition determinations. Complex 1 crystallizes in a monoclinic space group C2/c and each DPA-Cl ligand is tridentate to Ag(I) through the pyridine N and two monodentate carboxyl O atoms. The carboxy group with carbonyl C1 is semideprotonated and forms a symmetric hydrogen bond with a carboxy group of a neighboring complex. Complex 2 crystallizes in a triclinic lattice with space group P (Formula presented.) The Cd(II) ions are seven-coordinate and the coordination polyhedra can be described as a distorted pentagonal bipyramid. IR data are consistent with monodentate coordination of the carboxylate to Ag(I), Cd(II), and Pb(II) and observed wavenumber shifts confirm PDA-Cl ligand coordination to Pb(II) in 3. Thermal stability of anhydrous complexes indicates the metal–ligand interactions. The thermal stability of prepared compounds is reflected by the strength of interaction between metal–ligand and hydrogen bonds.
