A Tb(iii)-based coordination polymer (polyTb) was synthesized by complexation of Tb(NO3)3·(6H2O) and 4',4''''-[1,1'-biphenyl]-4,4'-diylbis[6,6''-bis(ethoxycarbonyl)2':6',2''-terpyridine](L). The polymer structure was determined by Job's plots, DFT calculation, and X-ray absorption fine structure (XAFS) measurement. Job's plots indicated that the mole ratio (Tb ion : L) is 1 : 1. The optimized model structures suggested a La model: the LaN6(O[double bond, length as m-dash]C)2 model. The bond distances of La-O and La-N are ∼2.80 Å and 2.60 Å, respectively. The EXAFS fitting indicated that the bond distances of Tb-O and Tb-N are 2.65 Å and 2.95 Å, respectively. polyTb shows field-induced magnetic relaxation in the solid and solution state. The luminescence of polyTb, originating from an f-f transition, was observed (φ = 6.9%). polyTb formed a porous structure on a Si substrate, whereas a fibrous complex structure was formed on glass. polyTb chains are orientated on glass, which were determined by XRD.
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J Phys Chem B
January 2025
Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, West Virginia 26506, United States.
measurement and mapping of oxygen levels within the tissues are crucial in understanding the physiopathological processes of numerous diseases, such as cancer, diabetes, or peripheral vascular diseases. Electron paramagnetic resonance (EPR) associated with biocompatible exogenous spin probes, such as Ox071 triarylmethyl (TAM) radical, is becoming the new gold standard for oxygen mapping in preclinical settings. However, these probes do not show tissue selectivity when injected systemically, and they are not cell permeable, reporting oxygen from the extracellular compartment only.
View Article and Find Full Text PDFHeliyon
January 2025
Division of Polymer Chemistry, Department of Chemistry, Atomic Energy Commission, P.O. Box: 6091, Damascus, Syrian Arab Republic.
The degree of sulfonation (DS) is a key property of sulfonated polymers, as it significantly influences their swelling behaviour, conductivity and mechanical properties. Accurately determining the DS is essential for optimizing these materials for various applications. In this work, the DS of sulfonated poly (ether ether ketone) (SPEEK) was evaluated using a combination of analytical techniques, including titration, back titration, Fourier Transform Infrared (FTIR), Ultra-Violet (UV) and proton nuclear magnetic resonance (H NMR) spectroscopies, Thermogravimetric analysis (TGA), Rutherford backscattering (RBS) and particle induced X-ray emission (PIXE) analysis.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
University of New Brunswick, UNB MRI Centre, Department of Physics, Fredericton, New Brunswick, E3B 5A3, Canada.
We observe divergent temperature-dependent magnetic resonance relaxation behaviors across various brine-saturated porous materials. The paramagnetic and diamagnetic nature of the samples underlies these divergent behaviors. The temperature-dependent trends of the longitudinal T_{1} and transverse T_{2} relaxation times are systematically explained via distinct relaxation-diffusion regimes of Brownstein-Tarr theory.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
The Department of Medical Imaging, Guangzhou Key Laboratory of Molecular Functional Imaging and Artificial Intelligence for Major Brain Diseases, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Jinan University, Guangzhou 518037 China. Electronic address:
Microwave dynamic therapy (MWDT) destroy tumor cells using reactive oxygen species (ROS), but its effectiveness is limited by low ROS production and intracellular oxygen (O) availability. This study presents a novel strategy using manganese (II) ion (Mn) doped iron (Fe)-based metal-organic framework (Fe MOF) nanoparticles (NPs) to enhance both O generation and ROS production for improved MWDT. Incorporating Mn into Fe MOF narrows the bandgap from 0.
View Article and Find Full Text PDFMed Phys
January 2025
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
Background: Previous studies have shown that in-beam magnetic resonance imaging (MRI) can be used to visualize a proton beam during the irradiation of liquid-filled phantoms. The beam energy- and current-dependent local image contrast observed in water was identified to be predominantly caused by beam-induced buoyant convection and associated flow effects. Besides this flow dependency, the MR signal change was found to be characterized by a change in the relaxation time of water, hinting at a radiochemical contribution, which was hypothesized to lie in oxygen depletion-evoked relaxation time lengthening.
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