Eu(III) Complexes of Octadentate 1-Hydroxy-2-pyridinones - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Eu(III) Complexes of Octadentate 1-Hydroxy-2-pyridinones write by . This book was released on 2009. Eu(III) Complexes of Octadentate 1-Hydroxy-2-pyridinones available in PDF, EPUB and Kindle. The luminescence properties of lanthanoid ions can be dramatically enhanced by coupling them to antenna ligands that absorb light in the UV-visible and then efficiently transfer the energy to the lanthanoid centre. The synthesis and the complexation of Ln{sup III} cations (Ln = Eu, Gd) for a ligand based on four 1-hydroxy-2-pyridinone (1,2-HOPO) chelators appended to a ligand backbone derived by linking two L-lysine units (3LI-bis-LYS) is described. This octadentate Eu{sup III} complex ([Eu(3LI-bis-LYS-1,2-HOPO)]−) has been evaluated in terms of its thermodynamic stability, UV-visible absorption and luminescence properties. For this complex, the conditional stability constant (pM) is 19.9, which is an order of magnitude higher than diethylenetriaminepentacetic acid at pH = 7.4. This Eu{sup III} complex also shows an almost two-fold increase in its luminescence quantum yield in aqueous solution (pH = 7.4) when compared with other octadentate ligands. Hence, despite a slight decrease of the molar absorption coefficient, a much higher brightness is obtained for [Eu(3LI-bis-LYS-1,2-HOPO)]−. This overall improvement was achieved by saturating the coordination sphere of the Eu{sup III} cation, yielding an increased metal-centred efficiency by excluding solvent water molecules from the metal's inner sphere.
Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials
Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials write by Ana de Bettencourt-Dias. This book was released on 2014-09-08. Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials available in PDF, EPUB and Kindle. This comprehensive book presents the theoretical principles, current applications and latest research developments in the field of luminescent lanthanide complexes; a rapidly developing area of research which is attracting increasing interest amongst the scientific community. Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials begins with an introduction to the basic theoretical and practical aspects of lanthanide ion luminescence, and the spectroscopic techniques used to evaluate the efficiency of luminescence. Subsequent chapters introduce a variety of different applications including: • Circularly polarized luminescence • Luminescence bioimaging with lanthanide complexes • Two-photon absorption of lanthanide complexes • Chemosensors • Upconversion luminescence • Excitation spectroscopy • Heterometallic complexes containing lanthanides Each chapter presents a detailed introduction to the application, followed by a description of experimental techniques specific to the area and an extensive review of recent literature. This book is a valuable introduction to the literature for scientists new to the field, as well as providing the more experienced researcher with a comprehensive resource covering the most relevant information in the field; a ‘one stop shop’ for all key references.
Australian Journal of Chemistry
Australian Journal of Chemistry - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Australian Journal of Chemistry write by . This book was released on 2009. Australian Journal of Chemistry available in PDF, EPUB and Kindle.
Trivalent Group 13 Metal Complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones
Trivalent Group 13 Metal Complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Trivalent Group 13 Metal Complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones write by Linda Simpson. This book was released on 1990. Trivalent Group 13 Metal Complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones available in PDF, EPUB and Kindle.
Solution Chemistry and Structure of Co(II), Fe(II) and Ni(II) Amide-Appended Macrocyclic ParaCEST Agents and Ln(III) Coordination to DNA Analogs
Solution Chemistry and Structure of Co(II), Fe(II) and Ni(II) Amide-Appended Macrocyclic ParaCEST Agents and Ln(III) Coordination to DNA Analogs - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Solution Chemistry and Structure of Co(II), Fe(II) and Ni(II) Amide-Appended Macrocyclic ParaCEST Agents and Ln(III) Coordination to DNA Analogs write by Abiola O. Olatunde. This book was released on 2014. Solution Chemistry and Structure of Co(II), Fe(II) and Ni(II) Amide-Appended Macrocyclic ParaCEST Agents and Ln(III) Coordination to DNA Analogs available in PDF, EPUB and Kindle. Transition metal paramagnetic chemical exchange saturation transfer (paraCEST) agents were developed and optimized as responsive pH-and temperature-dependent probes for magnetic resonance imaging (MRI). This dissertation is focused on the solution chemistry and solid state structures of the Co(II), Fe(II), and Ni(II) complexes of amide- appended triaza-, tetraaza-, and mixed aza-oxo macrocyclic paraCEST agents. Crystallographic data showed that nitrogen and oxygen donor atoms of the hexa-, hepta- or octa-dentate amide-append macrocyclic ligands coordinate to the metal ions and generated six-, seven- or eight- coordinate complexes. The proton NMR spectra of the complexes showed highly dispersed proton resonances that were either relatively sharp or broad depending on the metal center. Complexes were further characterized by monitoring their dissociation under biologically relevant conditions including solutions containing phosphate and carbonate or Zn(II) . Also, the dissociation of the complexes under acidic conditions (pD 2-4) was monitored over a 12 hour period. Solutions of the paraCEST agents in 20 mM HEPES (pH 7. 4) and 100 mM NaCl showed highly shifted (40-112 ppm) and intense CEST peaks (9-40%) at 37 degrees C on a 11. 7 T NMR spectrometer. Temperature-dependent CEST experiments uncovered complexes with improved sensitivity and temperature coefficient values in the range -0.56 to -0.12 ppm degrees C. Complexes were studied in rabbit serum, 4% agarose gel (w/w), or egg white to simulate possible in vivo interactions with biomacromolecules. CEST spectra with corresponding rate constants for proton exchange are reported under these conditions. CEST phantoms of the complexes on a 4. 7 T MRI scanner at 37 degrees C are compared. These in vitro CEST NMR and MRI experiments indicate that the complexes show promise for use as probes for mapping in vivo pH changes or paraCEST thermometry imaging. The third chapter of this dissertation is focused on the tetradentate PNA-HOPO and simple bidentate 1-Hydroxy-2-(1H)-pyridinone-2-carboxylic acid propylamide (Pr-1,2-HOPO) interaction with the nine coordinate Eu(III) ion. Peptide nucleic acids (PNA) that are modified to contain bidentate ligands for lanthanide ion binding are under development as target specific MRI contrast agents. The substitution of a nucleobase pair with 1,2-hydroxypyridinones (1,2-HOPO) introduced a binding site for lanthanide(III) ions in the HOPO-modified PNA duplex (PNA-HOPO). Non-modified PNA does not bind strongly to lanthanide(III) ions. Ln(III)-1,2-HOPO complexes are useful for sensitizing Ln(III) ion luminescence for biological imaging and Ln(III) based MRI. Direct excitation Ln(III) luminescence, sensitized luminescence, optical thermal melting experiments, and UV-vis titrations confirmed the coordination of the Eu(III) to PNA-HOPO. Studies of the PNA-HOPO duplex were compared to non-modified PNA duplex and Pr-1,2-HOPO to determine the binding mode.
