Host-Guest Symmetry Matching in Two Crystalline Magnesium Sulfate Oxalates Obtained Via a Solvent-Free Route.

The combination of π-conjugated oxalate anion with sulfate group has been explored in the solvent-free synthesis of two new magnesium sulfate oxalates. One of them has a layered structure crystallized in the noncentrosymmetric space group Ia, while the other has a chainlike structure crystallized in the centrosymmetric space group P21/c. The noncentrosymmetric solid has a wide optical bandgap and exhibits a moderate second-harmonic-generation response. Density functional theory calculations were carried out to disclose the origin of its second-order nonlinear-optical response.

Complexation of Cyclic Glutarimidedioxime with Cerium: Surrogating for Redox Behavior of Plutonium.

The complexation of cerium with glutarimidedioxime (H2L) was studied by potentiometry, ESI-mass spectrometry, and cyclic voltammetry. Crystallization of [CeIV(HL)3]+ from Ce3+ starting reactant indicated spontaneous complexation-driven oxidation. In aqueous solution, Ce3+ ions form three successive complexes, Ce(HL)2+, Ce(HL)2+, and Ce(HL)3 (where HL- stands for the singly deprotonated ligand). The interactions of glutarimidedioxime with metal ions are dominantly electrostatic in nature, and the stability constants of the complexes are correlated to the charge density of metal ions. Extrapolations of predicted stability constant (log ß) values were made from plotting effective charge and the ionic radius of the metal ion for Pu3+ and Pu4+. The stability constants of PuIV(HL)3+ and PuIII(HL)2+ are estimated to be 27.74 and 19.75, respectively. The differences of stability constants mean that glutarimidedioxime selectively binds Pu4+ over Pu3+ by a factor of about 8 orders of magnitude, suggesting Pu4+ would be stabilized by chelation with glutarimidedioxime. The mechanism of reduction of Pu4+ to Pu3+ in acidic solution is explained by decomposition of glutarimidedioxime through acid hydrolysis rather than a chelation-driven mechanism.

An electroless-plating-like solution approach for the preparation of PS@TiO2@Ag core-shell spheres.

PS@TiO2@Ag spheres with triple-level core-shell nanostructures were prepared via a versatile coating procedure based on an electroless-plating-like solution deposition (EPLSD) method. A peroxo-titanium-complex (PTC) aqueous solution was used as the precursor to react with an aniline monomer in the EPLSD preparation. Aniline plays an important role in the TiO2 layer anchoring process through the swollen effects of the PS cores. As extended, peroxo-metal-complex (PMC) with the d0 configuration can be introduced onto PS spheres to form varieties of PS@metal oxide core-shell structures by this method under mild conditions. Ag layers were then modified onto the PS@TiO2 spheres via the photocatalytic method. By the extraction of the PS cores, hollow TiO2 and TiO2@Ag spheres could be obtained. The photochemical degradation of methylene blue (MB) under UV light irradiation was performed on the composite nanostructures.

Fe/Zn-modified tricalcium phosphate (TCP) biomaterials: preparation and biological properties.

Bone repairing materials play an essential role in the repair treatment of bone defects. The presence of calcium phosphate invertebrates is of significance for bone repairing processes. However, the mechanical properties and osteogenic activities of many current calcium phosphate materials are not ideal, which limit their biological applications. Therefore, it is an effective alternative strategy to study the modification of calcium phosphate biomaterials to address these limitations. In this research, in order to enhance the biological performance of tricalcium phosphate (ß-TCP), metal species (Fe and Zn) modified ß-TCP materials through the co-precipitation method were successfully developed. The physical, chemical and biological properties of the binary composites were carefully studied for the first time. The bioactivities of the Fe-TCP and Zn-TCP were evaluated by simulating body fluid (SBF) immersion experiments, blood compatibility, and cytotoxicity tests. The findings demonstrated that the metal-TCP with excellent cytocompatibility and osteogenic properties shows good potential in medical applications.

Palladium-catalyzed C(carbonyl)-C bond cleavage of amides: a facile access to phenylcarbamate derivatives with alcohols.

A sulfur-containing auxiliary enabled palladium-catalyzed C(carbonyl)-C bond activation of amides was reported to form phenylcarbamate derivatives with alcohols. Both alkyl and benzyl alcohols could be employed well with yields up to 85%. Derivations from phenylcarbamates to ureas and thiocarbamates illustrated the potential applications of this sequential C-C cleavage/C-O coupling reaction.

Facile Access to Twisted Intramolecular Charge-Transfer Fluorogens Bearing Highly Pretwisted Donor-Acceptor Systems Together with Readily Fine-Tuned Charge-Transfer Characters.

Twisted intramolecular charge-transfer (TICT) fluorogens bearing highly pretwisted geometries and readily-fine-tuned charge-transfer characters are quite promising sensor and electroluminescence (EL) materials. In this study, by using 4-aryloxy-1,8-naphthalimide derivatives as the molecular framework, it is demonstrated for the first time that a CO bond could serve as the central bond to construct new TICT D-A systems. Photophysical and quantum chemical studies confirm that rotation around central CO bonds is responsible for the formation of a stable TICT state in these compounds. More importantly, owing to the structural adjustability of the aryl moiety and the strong steric interactions between the naphthalimide and the aryl ring systems, these compounds can display readily-fine-tuned TICT characters, hence exhibiting an adjustable solvent polarity threshold for aggregation-induced emission (AIE) activity, and could be AIE-active even in less-polar toluene and nonpolar cyclohexane. Furthermore, these compounds could possess highly-pretwisted ground-state geometries, hence could show good EL performance. The findings reveal a facile but effective molecular constructive strategy for versatile, high-performance optoelectronic TICT compounds.

Small molecular neutral microcrystalline iridium(III) complexes as promising molecular oxygen sensors.

Small molecular neutral Ir(III) complexes have been demonstrated to be promising self-inclusive microcrystalline thin-film oxygen sensors with relatively high sensitivity (Ksv = 6.41), good stability, and linear Stern-Volmer behavior (R(2) = 0.9979).

Crystal structure of 6-eth-oxy-pyridin-1-ium-2-olate.

In the title compound, C7H9NO2, all non-H atoms are essentially coplanar [r.m.s. deviation = 0.032 Å]. The largest deviation from the plane of the pyridine ring is 0.105 (6) Šfor the terminal C atom of the eth-oxy group. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers. These dimers are further linked by C-H⋯π inter-actions and weak π-π inter-actions between pyridine rings [centroid-centroid distance = 4.023 (1) Å].

A novel DC microplasma sensor constructed in a cavity PDMS chamber with needle electrodes for fast detection of methanol-containing spirit.

A novel microplasma device, for the first time, was constructed in a cavity Poly (dimethylsiloxane) (PDMS) chamber with two normal syringe needles serve as both the gas channels and the electrodes. This device employs argon plasma with direct current for molecular fragmentation and excitation. The microplasma is generated at atmospheric pressure in the PDMS chamber of 0.5 mL (5 × 10 × 10 mm(3)) volume with a sealable plug. Since the microplasma is maintained in a chamber by separation of the discharge zone and the substrate, stability for a long time of the microplasma is realized which could be observed by argon background emission fluctuation and SEM characterization. This property is beneficial for spectrometric detection of many volatile organics in this chamber. Besides, this kind of microplasma sensor has advantages such as flexibility in replacement of electrodes, convenience in clearance of the discharge chamber, small instrument volume, simple structure, and ease of operation. In addition, methanol-containing spirit samples were chosen to estimate the detecting performance of this microplasma for volatile organic compounds (VOCs) analysis by molecular emission spectrometry. Significant differences are observed upon the introduction of the spirit and the methanol-containing spirit samples. A detection limit of 0.3% is obtained on this microplasma device.

New open-framework cobalt sulfate-oxalates based on molecular and chain-like building blocks.

Presented here are two novel open-framework cobalt sulfate-oxalates constructed from molecular and chain-like building blocks. The two compounds have different structures: an hcb-type layer with 20-ring windows and a mog-type framework with 12-ring channels. Amine molecules play dual roles in the two structures: as a chelating ligand and a charge-balancing agent.

Solvent-free synthesis of new metal phosphite-oxalates with open-framework structures.

Two new metal phosphite-oxalates, CN3H6·Co(H2PO3)(C2O4) (1) and (CN3H6)2·Mn2.5(HPO3)(C2O4)2.5(H2O)·H2O (2), have been prepared under solvent-free conditions. The two open-framework compounds have diamondoid and pillared-layered structures, respectively. Their photoluminescence and magnetic properties were also investigated.

Crystal structure of (2-{3-[4-(4'-cyano-biphenyl-4-yl-oxy)but-oxy]pyridin-2-yl-κN}-5-(dodec-yloxy)phenyl-κC (1))(9-oxo-tetra-cos-7-en-7-olato-κ(2) O,O')platinum(II).

The central Pt(II) atom in the title compound, [Pt(C40H47N2O3)(C24H45O2)], has a slightly distorted square-planar coordination environment. The dihedral angle between the plane formed by Pt and the chelating C and N atoms and that formed by Pt and the chelating O atoms is 2.1 (3)°. The angle between the planes of the two rings in the biphenyl-4-carbo-nitrile unit is 35.1 (5)°. One lateral alkane chain is disordered over two sets of sites with site occupancy factors in a 0.595 (7):0.405 (7) ratio.

An open-framework rutile-type magnesium isonicotinate and its structural analogue with an anatase topology.

Two new photoluminescent magnesium-based coordination polymers, Mg(int)(2)·H(2)O (1) and Mg(nt)(2) (2), were synthesized under solvothermal conditions. Structural analyses reveal that they have different 3,6-connected frameworks with rutile- and anatase-type topologies, respectively. Compound 1 remains stable after the removal of its guest molecules and it exhibits weak ferroelectric behavior.

[2,6-Di-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl-κC (4)](penta-ne-2,4-dionato-κ(2) O,O')iridium(III).

The title compound, [Ir(C10H5F2N2)2(C5H7O2)], has a distorted octa-hedral coordination geometry around the Ir(III) atom, retaining the cis-C,C/trans-N,N chelate disposition in two 2,6-di-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl ligands which are nearly mutually perpendicular [dihedral angle = 82.75 (15)°]. The mol-ecular structure is stabilized by weak C-H⋯O and C-H⋯F hydrogen-bond inter-actions. The crystal structure is stabilized by π-π stacking inter-actions (centroid-centroid distance = 3.951 Å).

Two-dimensional assembly of tetrahedral chalcogenide clusters with tetrakis(imidazolyl)borate ligands.

A new two-dimensional inorganic-organic hybrid solid, formulated as Cd(17)S(4)(SPh)(25)B(im)(4) (SPh = benzenethiolate, im = imidazolate), has been synthesized under solvothermal conditions. The structure features a 6(3) network with 17-nuclear cadmium clusters linked by B(im)(4)(-) ligands. The compound is a semiconductor with the band gap of 2.66 eV and displays a green luminescence upon excitation at 390 nm.

A 3,4-connected beryllium phosphite framework containing 24-ring channels with a very low density.

A new three-dimensional open-framework beryllium phosphite with honeycomb-like channels has been prepared under solvothermal conditions. The alternation of a 24-ring window and a 30-ring window along its extra-large channel is unprecedented in open-framework materials. The compound has a very low density of 1.369 g cm(-3) by integrating an extra-large-pore, interrupted 3,4-connected framework and lightweight beryllium metal in its crystalline structure.

New semiconducting coordination polymers from zinc sulfide clusters and chains.

Two new semiconducting zinc coordination polymers, Zn(8)S(SPh)(14)(bpy) (1) and Zn(2)(SPh)(4)(bpy) (2), have been synthesized by a dual-ligand approach. Single-crystal structural analyses indicate that compound 1 has a helical-chain structure with P1 clusters bridging with bipyridyl (bpy) ligands and compound 2 possesses a layered structure with zinc sulfide chains cross-linked with bpy ligands. The diffuse-reflectance spectra reveal that the band gaps of the two compounds are 2.41 eV for 1 and 2.56 eV for 2.

(3-Benzoyl-1,7,7-trimethyl-bicyclo-[2.2.1]heptan-2-olato-κO,O)bis-[2-(2-pyrid-yl)phenyl-κC,N]iridium(III).

The title compound, [Ir(C(11)H(8)N)(2)(C(17)H(19)O(2))], has an octa-hedral coordination geometry around the Ir(III) atom, retaining the cis-C,C,trans-N,N chelate disposition of the two 2-phenyl-pyridine ligands. The chelate rings are nearly mutually perpendicular [the inter-planar angles range from 85.48 (17) to 89.17 (19)°]. The two 2-(2-pyrid-yl)phenyl ligands are approximately planar, with the plane of the phenyl ring being inclined to that of the pyridine ring by 2.3 (3) and 5.1 (3)° in the two ligands. The inter-planar angle between the phenyl ring in 3-benzoyl-camphor and the IrO(2)C(3) chelate ring is 35.5 (2)°.

2-Dimensional micro-network of boron-doped diamond film: fabrication and electrochemical sensing application.

By means of delicate and conventional methods based on photolithography and hot filament chemical vapor deposition (HFCVD) technology, a novel boron-doped diamond micro-network (BDDMN) film was fabricated, and this micro-structure showed excellent electrochemical sensing properties.