Bright X-ray and up-conversion nanophosphors annealed using encapsulated sintering agents for bioimaging applications.

Nanophosphors are promising contrast agents for deep tissue optical imaging applications because they can be excited by X-ray and near infrared light that penetrates deeply through tissue and generates almost no autofluorescence background in the tissue. For these bioimaging applications, the nanophosophors should ideally be small, monodispersed and brightly luminescent. However, most methods used to improve luminescence yield by annealing the particles to reduce crystal and surface defects (e.

M3(P2O7)22--type open frameworks featuring [M2O8] and [M3O12] multinuclear transition-metal oxide units. Serendipitous synthesis of six polymorphic salt-inclusion magnetic solids: Na2M3(P2O7)2·ACl (M = Mn, Fe; A = Rb, Cs) and K2M3(P2O7)2·CsCl (M = Fe, Mn).

Single crystals of six polymorphic salt-inclusion phosphates of the A(2)M(3)(P(2)O(7))(2)·A'Cl type, Na(2)Mn(3)(P(2)O(7))(2)·CsCl (1), Na(2)Mn(3)(P(2)O(7))(2)·RbCl (2), Na(2)Fe(3)(P(2)O(7))(2)·CsCl (3), Na(2)Fe(3)(P(2)O(7))(2)·RbCl (4), K(2)Mn(3)(P(2)O(7))(2)·CsCl (5), and K(2)Fe(3)(P(2)O(7))(2)·CsCl (6), were grown in reactive molten chloride flux media. Compounds 1-4 are isostructural and crystallize in the space group C2/c (No. 15), while 5 and 6 crystallize in P2/c (No.

Multifunctional yolk-in-shell nanoparticles for pH-triggered drug release and imaging.

Multifunctional nanoparticles are synthesized for both pH-triggered drug release and imaging with radioluminescence, upconversion luminescent, and magnetic resonance imaging (MRI). The particles have a yolk-in-shell morphology, with a radioluminescent core, an upconverting shell, and a hollow region between the core and shell for loading drugs. They are synthesized by controlled encapsulation of a radioluminescent nanophosphor yolk in a silica shell, partial etching of the yolk in acid, and encapsulation of the silica with an upconverting luminescent shell.

Iron-Loaded Magnetic Nanocapsules for pH-Triggered Drug Release and MRI Imaging.

Magnetic nanocapsules were synthesized for controlled drug release, magnetically assisted delivery, and MRI imaging. These magnetic nanocapsules, consisting of a stable iron nanocore and a mesoporous silica shell, were synthesized by controlled encapsulation of ellipsoidal hematite in silica, partial etching of the hematite core in acid, and reduction of the core by hydrogen. The iron core provided a high saturation magnetization and was stable against oxidation for at least 6 months in air and 1 month in aqueous solution.

Synthesis and structure of bismuth(III)-containing noncentrosymmetric phosphates, Cs3KBi2M4(PO4)6Cl (M = Mn, Fe). Monoclinic (Cc) and tetragonal (P43) polymorphs templated by chlorine-centered Cl(Bi2Cs) acentric units.

Single crystals of three new noncentrosymmetric (NCS) phosphates, α (1) and β (2) forms of Cs(3)KBi(2)Mn(4)(PO(4))(6)Cl and α-Cs(3)KBi(2)Fe(4)(PO(4))(6)Cl (3), were grown in a reactive CsCl/KCl molten-salt media. Their structures were determined by single-crystal X-ray diffraction methods showing that the α form crystallizes in the space group Cc (No. 9), which is in one of the 10 NCS polar crystal classes, m (2/m) while the β form crystallizes in P4(3) (No.

Symmetry preservation in a new noncentrosymmetric lattice comprised of acentric POM clusters residing in bowls of Cs(+)-based half SOD β-cage.

In light of ever growing interests in noncentrosymmetric materials, a fascinating reticular chemistry is illustrated via the structure of a new family of solids where the acentric symmetry of the well-known [V(4+)(14)As(3+)(8)O(42)Cl](5-) POM cluster is manifested through the network construction of counter cations featuring slabs of Cs(+)-based half SOD β-cages.

Extended utility of molten-salt chemistry: unprecedented synthesis of a water-soluble salt-inclusion solid comprised of high-nuclearity vanadium oxide clusters.

Polyoxometallates (POMs) are desirable in materials applications ranging from uses as catalysts in selective oxidation reactions to molecular-like building blocks for the preparation of new extended solids. With the use of an unprecedented approach involving high temperature, molten salt methods, a fascinating series of salt-inclusion solids (SISs) that contain high nuclearity POMs has been isolated for the first time. Cs(11)Na(3)(V(15)O(36))Cl(6) (1) was synthesized using the eutectic NaCl/CsCl flux (mp 493 °C) which serves as a reactive solvent in crystal growth and allows for the SIS formation.

Evidence for surface states in pristine and Co-doped ZnO nanostructures: magnetization and nonlinear optical studies.

An unexpected presence of ferromagnetic (FM) ordering in nanostructured ZnO has been reported previously. Recently, from our detailed magnetization studies and ab initio calculations, we attributed this FM ordering in nanostructured ZnO to the presence of surface states, and a direct correlation between the magnetic properties and crystallinity of ZnO was observed. In this study, through a systematic sample preparation of both pristine and Co-doped ZnO nanostructures, and detailed magnetization and nonlinear optical (NLO) measurements, we confirm that the observed FM ordering is due to the presence of surface states.

Salt-templated mesoporous solids comprised of interlinked polyoxovanadate clusters.

The utility of molten salts has been demonstrated in the synthesis of the first family of mesoporous salt-inclusion solids featuring [V(4)O(16)] and [V(5)O(17)] polyoxovanadate (POV) units interlinked by As(5+) cations. Despite a high-temperature synthesis, these new solids exhibit unusually porous ( approximately 2-nm-diameter) vanadium arsenate frameworks. Disordered metal chloride salts reside inside the pores, leading to relatively large voids (up to approximately 7.

Synthesis, structure, and magnetic properties of Na3LnMn3O3(AsO4)3 (Ln = La, Sm, and Gd): a new 3d-4f series exhibiting one-dimensional manganese(III) oxide chains connected via LnO9 units.

In attempts to synthesize compounds containing mixed lanthanide and transition metal oxide magnetic nanostructures, a new 3d-4f arsenate phase, Na(3)GdMn(3)O(3)(AsO(4))(3), was isolated using high-temperature, molten-salt methods. The X-ray single-crystal structure analysis shows that Na(3)GdMn(3)O(3)(AsO(4))(3) crystallizes in a hexagonal space group with a = 11.091(2) A, c = 5.

Synthesis, structure, and magnetic properties of Cs(2-x)RbxCu3P4O14 (0.0

In our continued exploratory synthesis of compounds containing transition-metal oxide magnetic nanostructures, a new copper(II) phosphate phase, Cs2Cu3P4O14 (1), was isolated employing the mixed CsCl/2CsI molten flux. The X-ray single-crystal structural analysis shows that the Cs2Cu3P4O(14) phase crystallizes in a monoclinic space group with a = 7.920(2) A, b = 10.

New cuprates featuring ladderlike periodic arrays of [Cu3O8]10- trimeric magnetic nanostructures.

A new family of cuprates, Li2Cu3(SiO3)4 (1) and Na2Cu3(GeO3)4 (2), was isolated in molten salt media. The extended lattices contain ladderlike periodic arrays of [Cu3O8]10- magnetic nanostructures. Magnetic properties of the Na2Cu3Ge(4-x)SixO12 series, where x = 0, 0.

Salt-inclusion synthesis of two new polar solids, Ba6Mn4Si12O34Cl3 and Ba6Fe5Si11O34Cl3.

A new family of salt-containing, mixed-metal silicates (CU-14), Ba6Mn4Si12O34Cl3 (1) and Ba6Fe5Si11O34Cl3 (2), was synthesized via the BaCl2 salt-inclusion reaction. These compounds crystallize in the noncentrosymmetric (NCS) space group Pmc2(1) (No. 26), adopting 1 of the 10 NCS polar, nonchiral crystal classes, mm2 (C2v).

Salt-inclusion synthesis of Ba2MnSi2O7Cl. A fresnoite-type polar framework containing the acentric [Si2O7]6 - polyanion in the anti-ReO3 type [(Ba2Mn)Cl]6+) cage.

A novel non-centrosymmetric (NCS) solid, Ba(2)Mn(Si(2)O(7))Cl (CU-13), was isolated via high-temperature, salt-inclusion reactions. This manganese(III) silicate chloride adopts the fresnoite structure exhibiting pseudo-one-dimensional channels in which the Ba(2+) cations reside. The framework can be viewed alternatively as made of a fascinating anti-ReO(3) type (Ba(2)Mn)Cl lattice centered on the acentric Si(2)O(7) unit.

Nanostructured magnetic cuprate cluster: synthesis, structure, UV-Vis spectroscopy, and magnetic properties of a new copper(II) arsenate NaCuAsO4 containing discrete [Cu4O16]24- clusters.

Crystals of copper(II) arsenate NaCuAsO(4) were grown by conventional high-temperature, solid-state methods in molten-salt media. The compounds were characterized by single crystal X-ray diffraction, UV-vis spectroscopy, and magnetic susceptibility measurements. NaCuAsO(4) crystallizes in a monoclinic lattice with a = 6.

The fascinating noncentrosymmetric copper(II) phosphates synthesized via CsCl salt-inclusion.

Two new noncentrosymmetric (NCS) solids were isolated via high-temperature, salt-inclusion reactions, Cs(2)Cu(7)(P(2)O(7))(4).6CsCl (1, CU-9) and Cs(2)Cu(5)(P(2)O(7))(3).3CsCl (2, CU-11).

A new class of hybrid materials via salt inclusion: novel copper(II) arsenates Na(5)ACu(4)(AsO(4))(4)Cl(2) (A = Rb, Cs) composed of alternating covalent and ionic lattices.

Two novel copper(II) arsenates Na5ACu4(AsO4)4Cl2 (A = Rb, Cs) were synthesized by conventional solid-state methods using reactive molten salt media. These compounds are isostructural and crystallize in an orthorhombic lattice (Fmmm, No. 69; Z = 8).

High-temperature synthesis of Rb2MnP2S6 in molten salt medium.

Transparent yellow plates of rubidium manganese hexathiodiphosphate, Rb(2)MnP(2)S(6), were synthesized in molten RbBr. The compound is isotypic to other compounds of the type A(2)MP(2)Q(6) (A = K, Rb, Cs; M = Mn, Fe; Q = S, Se). Its structure can be viewed as columns of face-sharing S(6) polyhedra parallel to the a axis, interconnected by Rb(+).

Na(4)Mn(0.5)P(0.5)O(5): Synthesis of a Novel Mixed-Metal Manganese(VII)/Phosphorus(V) Oxide via Hydroxide Flux.

Vibrant blue crystals of Na(4)Mn(0.5)P(0.5)O(5) were synthesized via a sodium hydroxide flux.