Nanoscale metal-organic framework (nMOF) is a distinctive type of crystalline compounds that consists of metal ions or clusters coordinated to organic ligands. This hybrid material has attracted fast-growing attention due to its tunable pore sizes, remarkably large surface areas, and high selectivity in uptaking small molecules. In this paper, we successfully developed a novel approach for synthesizing a core-shell structure with MIL-88B-4CH as a tunable nMOF shell and MnFeO as a magnetic core. We controlled the growth of the core-shell particles by introducing different acetic acid concentrations and with varied reaction time. Acetic acid works as a modulating agent that allows for nucleation rate control, leading to tailored particle size. Our results show an increase in the particle size with increasing acetic acid concentration or reaction time. This study provides a valuable methodology for synthesis of core-shell nanoparticles with controlled sizes based on nMOF platforms.

The mineral component of bone and other biological calcifications is primarily a carbonate substituted calcium apatite. Integration of carbonate into two sites, substitution for phosphate (B-type carbonate) and substitution for hydroxide (A-type carbonate), influences the crystal properties which relate to the functional properties of bone. In the present work, a series of AB-type carbonated apatites (AB-CAp) having varying A-type and B-type carbonate weight fractions were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and carbonate analysis. A detailed characterization of A-site and B-site carbonate assignment in the FTIR ν region is proposed. The mass fractions of carbonate in A-site and B- site of AB-CAp correlate differently with crystal axis length and crystallite domain size. In this series of samples reduction in crystal domain size correlates only with A-type carbonate which indicates that carbonate in the A-site is more disruptive to the apatite structure than carbonate in the B-site. High temperature methods were required to produce significant A-type carbonation of apatite, indicating a higher energy barrier for the formation of A-type carbonate than for B-type carbonate. This is consistent with the dominance of B-type carbonate substitution in low temperature synthetic and biological apatites.

A series of Fe-bearing LiLaZrO (LLZO) garnets was synthesized using solid-state synthesis methods. The synthetic products were characterized compositionally using electron microprobe analysis and inductively coupled plasma optical emission spectroscopy (ICP-OES) and structurally using X-ray powder diffraction and Fe Mössbauer spectroscopy. A maximum of about 0.25 Fe pfu could be incorporated in Li Fe LaZrO garnet solid solutions. At Fe concentrations lower than about 0.16 pfu, both tetragonal and cubic garnets were obtained in the synthesis experiments. X-ray powder diffraction analysis showed only a garnet phase for syntheses with starting materials having intended Fe contents lower than 0.52 Fe pfu. Back-scattered electron images made with an electron microprobe also showed no phase other than garnet for these compositions. The lattice parameter, , for all solid-solution garnets is similar with a value of ≈12.98 Å regardless of the amount of Fe. Fe Mössbauer spectroscopic measurements indicate the presence of poorly- or nano-crystalline FeLaO in syntheses with Fe contents greater than 0.16 Fe pfu. The composition of different phase pure Li Fe LaZrO garnets, as determined by electron microprobe (Fe, La, Zr) and ICP-OES (Li) measurements, give LiFeLaZrO, LiFeLaZrO, LiFeLaZrO, and LiFeLaZrO. The Fe Mössbauer spectrum of cubic LiFeLaZrO garnet indicates that most Fe occurs at the special crystallographic 24 position, which is the standard tetrahedrally coordinated site in garnet. Fe in smaller amounts occurs at a general 96 site, which is only present for certain Li-oxide garnets, and in LiFeLaZrO this Fe has a distorted 4-fold coordination.

Progressive chemical .delithiation of commercially available lithium cobalt oxide ([Formula: see text]) showed consecutive changes in the crystal properties. Rietveld refinement of high resolution X-ray and neutron diffraction revealed an increased lattice parameter and a reduced lattice parameter for chemically delithiated samples. Using electron microscopy we have also followed the changes in the texture of the samples towards what we have found is a critical layer stoichiometry of about [Formula: see text] with =1/3 that causes the grains to exfoliate. The pattern of etches by delithiation suggests that unrelieved strain fields may produce chemical activity.

The stannides CuLiSn (CSD-427095) and CuLiSn (CSD-427096) were synthesized by induction melting of the pure elements and annealing at 400 °C. The phases were reinvestigated by X-ray powder and single-crystal X-ray diffractometry. Within both crystal structures the ordered CuSn and CuSn lattices form channels which host Cu and Li atoms at partly mixed occupied positions exhibiting extensive vacancies. For CuLiSn, the space group F-43m. was verified (structure type CuHgTi; =6.295(2) Å; (²)=0.0355 for 78 unique reflections). The 4() and 4() positions are occupied by Cu atoms and Cu+Li atoms, respectively. For CuLiSn, the space group 6/ was confirmed (structure type InPtGd; =4.3022(15) Å, =7.618(3) Å; (²)=0.060 for 199 unique reflections). The Cu and Li atoms exhibit extensive disorder; they are distributed over the partly occupied positions 2(), 2() and 4(). Both phases seem to be interesting in terms of application of Cu-Sn alloys as anode materials for Li-ion batteries.

Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse P NMR linewidth and inverse Raman PO ν bandwidth were both correlated with powder XRD crystallinity over the 0.3-10.3 wt% CO range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the P NMR chemical shift frequency and the Raman phosphate ν band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals.

CeBOF is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO] groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group (No. 61) with eight formula units and the lattice parameters =821.63(5), =1257.50(9), =726.71(6) pm, =750.84(9) Å, =0.0698, and =0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO] groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed.

Silver vanadium phosphorous oxides (AgVPO) are notable battery cathode materials due to their high energy density and demonstrated ability to form in-situ Ag metal nanostructured electrically conductive networks within the cathode. While analogous silver vanadium diphosphate materials have been prepared, electrochemical evaluations of these diphosphate based materials have been limited. We report here the first electrochemical study of a silver vanadium diphosphate, AgVPO, where the structural differences associated with phosphorous oxides versus diphosphates profoundly affect the associated electrochemistry. Reminiscent of AgVOPO reduction, formation of silver metal nanoparticles was observed with reduction of AgVPO. However, counter to AgVOPO reduction, AgVPO demonstrates a significant decrease in conductivity upon continued electrochemical reduction. Structural analysis contrasting the crystallography of the parent AgVPO with that of the proposed LiVPO reduction product is employed to gain insight into the observed electrochemical reduction behavior, where the structural rigidity associated with the diphosphate anion may be associated with the observed particle fracturing upon deep electrochemical reduction. Further, the diphosphate anion structure may be associated with the high thermal stability of the partially reduced AgVPO materials, which bodes well for enhanced safety of batteries incorporating this material.

Organofunctionalized apatite nanoparticles were prepared using a one step process involving dissolution/precipitation of natural phosphate rock and covalent grafting of nitrilotris(methylene)triphosphonate (NTP). The synthesized materials were characterized by Brunauer-Emmett-Teller (BET) surface measurement, thermogravimetry, inductively coupled plasma emission spectroscopy (ICP-ES), elemental analysis, multinuclear solid state cross-polarization/magic angle spinning (CP/MAS) and single-pulse NMR spectroscopy, transmission electron microscopy (TEM) and energy dispersive x-ray analysis (EDXA). After grafting BET measurements yielded particle specific surface areas ranging from 88 to 193 m(2) g(-1) depending on the grafted phosphonate. The results show that the surfaces of the nanoapatite particles can be covered with functional groups bound through a variable number of R-P-O-Ca bonds to render them organoapatites.

Three novel zinc coordination polymers (NH(4))(n)[Zn(Hida)Cl(2)](n) (1), [Zn(ida)(H(2)O)(2)](n) (2), [Zn(Hida)(2)](n)·4nH(2)O (3) (H(2)ida = iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H(2)O)]·2H(2)O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and π-π stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on (1)H and (13)C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H(2)O)(3)] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide.

Multifunctional colloidal core-shell nanoparticles of magnetic nanocrystals (of iron oxide or FePt) or gold nanorods encapsulated in silica shells doped with the fluorescent dye, Tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy) were synthesized. The as-prepared magnetic nanocrystals are initially hydrophobic and were coated with silica using a microemulsion approach, while the as-prepared gold nanorods are hydrophilic and were coated with silica using a Stöber-type of process. Each approach yielded monodisperse nanoparticles with uniform fluorescent dye-doped silica shells. These colloidal heterostructures have the potential to be used as dual-purpose tags-exhibiting a fluorescent signal that could be combined with either dark-field optical contrast (in the case of the gold nanorods), or enhanced contrast in magnetic resonance images (in the case of magnetic nanocrystal cores). The optical and magnetic properties of the fluorescent silica-coated gold nanorods and magnetic nanocrystals are reported.

Monodispersed cobalt nanoparticles (NPs) with controllable size (8-14 nm) have been synthesized using thermal decomposition of dicobaltoctacarbonyl in organic solvent. The as-synthesized high magnetic moment (125 emu/g) Co NPs are dispersible in various organic solvents, and can be easily transferred into aqueous phase by surface modification using phospholipids. However, the modified hydrophilic Co NPs are not stable as they are quickly oxidized, agglomerated in buffer. Co NPs are stabilized by coating the MFe(2)O(4) (M = Fe, Mn) ferrite shell. Core/shell structured bimagnetic Co/MFe(2)O(4) nanocomposites are prepared with tunable shell thickness (1-5 nm). The Co/MFe(2)O(4) nanocomposites retain the high magnetic moment density from the Co core, while gaining chemical and magnetic stability from the ferrite shell. Comparing to Co NPs, the nanocomposites show much enhanced stability in buffer solution at elevated temperatures, making them promising for biomedical applications.