ABSTRACT Lanthanide-doped gadolinium nanomaterials have attracted considerable attention due to their promising applications in biological imaging. Sodium gadolinium fluoride (β-NaGdF4) nanomaterials act as perfect host for doping of luminescent lanthanide ions. Due to heavy nature of gadolinium, it can strongly absorb X-ray radiations. Therefore, Gd-based nanomaterials are applied as contrast agents for X-ray tomography (CT). Presence of seven unpaired electrons in Gd+3 ion, its large magnetic moment and long electronic relaxation time makes it an ideal candidate to enhance water proton relaxation rates. These characteristics make Gd-based nanomaterial useful for their potential application as MRI contrast agents. In this work, sodium gadolinium fluoride is doped with ytterbium and erbium to produce β-NaGdF4:Yb/Er as core nanocrystals. They are subsequently coated with sodium gadolinium fluoride doped with neodymium (β-NaGdF4:Nd) to produce β-NaGdF4:Yb/Er@β-NaGdF4:Nd core-shell nanocrystals. Powder X‐ray diffraction (XRD) results indicated that β-NaGdF4 (host), β-NaGdF4:Yb/Er (core) and β-NaGdF4:Yb/Er@β-NaGdF4:Nd (core-shell) nanocrystals all exist in hexagonal crystalline phase. While Dynamic Light Scattering (DLS) results indicated that the particle size of the synthesized nanocrystals was in range of 12 to 27 nm. FTIR results confirmed that the synthesized nanocrystals were stabilized by oleic acid. Nanocrystals reported in this work are expected to be useful trimodal contrast agents for photoluminescence, X-ray tomography and Magnetic Resonance Imaging (MRI).

Deprotonation of 2-acetylpyridine was carried out in the presence of NaH as a phase transfer catalyst instead of NaOH to minimize side products formation. The products were then treated with two equivalents of alkyl/aryl halide to synthesize a variety of acetyl pyridine derivatives. The compounds were structurally characterized by 1H- and 13C-NMR spectroscopy in solution state. Structure of compound 2 was also confirmed in solid state by X-ray diffraction. Electronic properties such as Mulliken charges, frontier molecular orbitals (HOMO-LUMO), ionization energy (IE), electron affinity (EA), global hardness (η), Chemical Potential (µ) and Global electrophilicity (ω) of some compounds were investigated by the same theory using B3LYP-6-311G basis set.

Zirconia was prepared by a precipitation method and calcined at 723 K, 1023 K, and 1253 K in order to obtain monoclinic zirconia. The prepared zirconia was characterized by XRD, SEM, EDX, surface area and pore size analyzer, and particle size analyzer. Monoclinic ZrO2 as a catalyst was used for the gas-phase oxidation of isopropanol to acetone in a Pyrex-glass-flow-type reactor with a temperature range of 443 K - 473 K. It was found that monoclinic ZrO2 shows remarkable catalytic activity (68%) and selectivity (100%) for the oxidation of isopropanol to acetone. This kinetic study reveals that the oxidation of isopropanol to acetone follows the L-H mechanism.