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Protein phosphorylation regulates and controls protein activity and function, which is the most basic and important part in organisms' lives. However, the low abundance and ionization inhibition of phosphopeptides make it difficult to understand and analyze the protein phosphorylation mechanism. In this study, we synthesize a core‐shell structured magnetic Ti4+‐based immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides. The introduction of negatively charged carbon layer increases the specific surface area and avoids loss of the immobilized Ti4+ during sample loading and washing. The synthesized magnetic superhydrophilic extractant is employed to separate and enrich phosphopeptides from standard protein digests coupled with MALDI‐TOF MS. It exhibits excellent enrichment performance of high selectivity (1 : 2000 molar ratio of β‐casein and BSA), sensitivity (low detection limit of 4 fmol) and preferable reusability (at least 12 times) as well as excellent adsorption capacity of 142.5 mg ⋅ g−1 and high recovery rate of 85.6 %. Moreover, sixteen phosphopeptides and four endogenous phosphopeptides can be accurately identified from non‐fat milk and human serum, further indicating the great potential and bright application in phosphoproteomics analysis. [ABSTRACT FROM AUTHOR]

Chitosan (Cts), a positively charged natural polysaccharide, is employed to functionalize mesoporous titanium dioxide (mTiO2) nanoparticles. The prepared Cts/mTiO2 composite was used as a stationary phase to coat the inner wall of fused‐silica capillary and obtain uniform Cts/mTiO2 film. The Cts/mTiO2 film is applied to detect and enrich phosphopeptides in complex biological samples based on typical in‐tube solid phase microextraction (IT‐SPME) system. This unique Cts/mTiO2 film exhibits excellent enrichment performances of high selectivity (β‐casein and BSA in molar ratio of 1 : 1000), sensitivity (detection limit as low as 40 fmol of β‐casein tryptic digest solution) and high adsorption capacity (124.5 μg mg−1). Meanwhile, the Cts/mTiO2 film possesses preferable reusability and can be reused more than 10 times. These results confirm that the Cts/mTiO2 film possesses potential and satisfactory prospects in phosphoproteomics analysis. [ABSTRACT FROM AUTHOR]

Hexagonal (NH4)xWO3 has emerged as a promising photothermal agent in recent years due to the charge compensation reaction when cation intercalation occurs. We chose the ammonium ion to intercalate into the hexagonal crystal channel of tungsten oxide because of its appropriate ion radius and unique interaction with the hexagonal channel. The transmission electron microscope image shows that the morphology of the as‐prepared (NH4)xWO3 is a nanorod with a 10 nm radius and 50 nm length. The product exhibits strong absorption across the whole near infrared and ultraviolet light spectrum, as well as part of the visible light spectrum. Moreover, it exhibits a photothermal conversion efficiency up to 69.3 % at 808 nm with good photothermal stability, and features excellent biocompatibility during the co‐culture process with MC3T3‐E1 cells. Ammonium was intercalated into the hexagonal crystal channel of tungsten oxide to produce hexagonal (NH4)xWO3 as nanorods with a 10 nm radius and 50 nm length. The product exhibits strong absorption across the whole near infrared and ultraviolet light spectrum, as well as part of the visible light spectrum. Moreover, it exhibits a photothermal conversion efficiency up to 69.3 % at 808 nm with good photothermal stability, and features excellent biocompatibility during the co‐culture process with MC3T3‐E1 cells. [ABSTRACT FROM AUTHOR]

The design of efficient catalysts for the selective oxidation of sp3 C–H bond with air at low temperature is of great importance to the scientific and industrial community. In this work, we design a CeO2–δ modified CuFe2O4 catalyst by a post‐modification method for the selective oxidation of fluorene under an air atmosphere and N‐hydroxyphthalimide (NHPI) at 60 °C. HRTEM results indicate that CeO2–δ nanoclusters sized around 5 nm are successfully modified on the surface of CuFe2O4. XPS and H2‐TPR results show that CeO2–δ modification would favor oxygen transfer at lower temperature due to the synergetic effect between CuFe2O4 and CeO2–δ with rich Ce3+/Ce4+ couples. The results demonstrate that CuFe2O4@CeO2–δ‐0.05 with 4.20 wt.‐% Ce present the best catalytic performance with 94 % conversion of fluorene and excellent reusability at least five times. It is anticipated that the modification of CeO2–δ nanoclusters on the surface leads to increased oxygen activation and transfer to CuFe2O4, which favors the activation of NHPI to phthalimide‐N‐oxyl (PINO) radicals and exhibits an improved catalytic performance. Our results provide some guidance on the design of efficient catalysts by the surface modification strategy. CeO2–δ modification with 4.20 wt.‐% Ce on the surface of CuFe2O4 nanoparticles favors oxygen transfer at lower temperature and leads to better catalytic activity than that of pure CuFe2O4 for the aerobic selective oxidation of fluorene due to the synergetic effect between CuFe2O4 and CeO2–δ with Ce3+/Ce4+. [ABSTRACT FROM AUTHOR]

Abstract: An effective three‐component fixation of atmospheric CO2 with readily available 1,2‐dichloroethane and aromatic amine toward oxazolidinones catalyzed by in situ NHC was developed. The reaction occurred in good to excellent yields with good generality and wide functional group tolerance, including challenging steric hindered substituted‐dichloroethane (e.g. 1,2‐dichloropropane and 2,3‐dichlorobutane). The catalytic system is not sensitive to air and moisture, and high yield of oxazolidinone was achieved even with about 0.3 atm of pressure of carbon dioxide. The mechanistic study suggests that the reaction catalyze by in situ NHC via NHC‐CO2 adduct, 1‐butyl‐3‐methylimidazolium‐2‐carboxylate as intermediate and aminochloride involves in reaction pathways. The catalyst can be recycled for at least 3 times without obvious loss of catalytic activity. The protocol is also effective to prepare six‐membered 3‐aryl‐1,3‐oxazinan‐2‐one and even seven‐membered 3‐aryl‐1,3‐oxazepan‐2‐one, when 1,3‐dichloropropane and 1,4‐dichlorobutane was employed. [ABSTRACT FROM AUTHOR]

W18O49 with a tunable oxidation state was prepared by addition of NaNO3 or NaBH4 as a redox agent in the solvothermal system. The addition of redox agents has no influence on the crystallization of W18O49. The obtained W18O49 structures keep their morphology as a bundle of nanowires with a regular hexagonal on the cross-section. W18O49 exhibits strong valence-dependent absorption features in the near-IR region. Reduced W18O49 with more W5+ has a higher concentration of oxygen vacancies, which enhances the localized surface plasmon resonance effect. Reduced W18O49 exhibits a high photothermal conversion efficiency of 59.6 % and has good photothermal stability. [ABSTRACT FROM AUTHOR]

An extremely stable Tb coordination polymer, TbL2 [HL = 4-(pyrimidin-5-yl)benzoic acid], was synthesized. It exhibits high thermal and chemical stability. TbL2 is a visual multiresponsive luminescent probe that can selectively detect F- among the same main-group anions as well as various pollutant phosphorus anions. [ABSTRACT FROM AUTHOR]

The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography. This bcc structure is in striking contrast with the fcc structure of bulk gold and conventional Au nanoparticles, as well as the bi-icosahedral structure of [Au38(SCH2CH2Ph)24]. The bcc nanocluster has a distinct HOMO-LUMO gap of ca. 1.5 eV, much larger than the gap (0.9 eV) of the bi-icosahedral [Au38(SCH2CH2Ph)24]. The unique structure of the bcc gold nanocluster may be promising in catalytic applications. [ABSTRACT FROM AUTHOR]

A series of [PdPyCl2]2(di-NHC) complexes were prepared (di-NHC are two 1-(2,6-dimethylphenyl)imidazolidene molecules bridged by an aliphatic -(CH2) n- linker ( n = 3, 4, 5, 6, and 10)). All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of four complexes ( n = 3, 4, 5 and 6) were determined by X-ray diffraction. The influence of the distant methyl group on the structural features and catalytic activity with increasing of length of linker was investigated by comparing the results of these 2,6-dimethylphenyl palladium complexes with those of their known mesityl analogues. X-ray studies show the distant methyl substitution has big impact on the structure feature of the complexes with the shorter linker between two NHC (ethylene and propylene), but has a little or no effect on that of the complexes with longer linker (butylene and hexylene). Catalytic results of the arylation of styrene show that the remote substitute has big effect on the regioselectivity of the product in all complexes with shorter and longer linkers, but has a limited effect on the yield. [ABSTRACT FROM AUTHOR]

palladium complexes of ferrocenyl-functionalized N-heterocyclic carbenes with different substituents were synthesized. The molecular structures of selected complexes were determined by X-ray diffraction and show a pseudo-square-planar structure with a central palladium atom surrounded by carbene, pyridine, and two chloride ligands. The influence of the different substituents on the structure and reactivity of the complexes was studied. The catalytic properties of the complexes were investigated in the Larock indolization reactions of 2-bromoanilines with diphenylacetylene. Their performances slightly varied in this reaction, but the complex with mesityl substituent showed the best activity. [ABSTRACT FROM AUTHOR]

A series of imidazole-based and benzimidazole-based di-NHC dipalladium complexes with alkyl bridges of different chain lengths were prepared. All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of three complexes were determined by X-ray diffraction. X-ray studies show the length of linker effects the solid structure of these complexes and π-π stacking plays an important role for the configuration of NHC-Pd-Py subunits. The activity of NHC-palladium complexes was investigated in the mono- and double-Heck reactions, and the imidazole-based palladium complex bearing the shortest ethylene bridge shows the best activity and selectivity in both reactions. [ABSTRACT FROM AUTHOR]

A flexible, self‐floating W18O49/carbon foam composite is fabricated by calcining melamine foam with W18O49 as an adsorbate in N2 atmosphere. This self‐floating property is simply realized by a carbonization process other than the complicated surface modification process. The simple synthesis procedure helps to increase not only the solar absorption but also the retention of W18O49 in the porous net structure. This composite absorbs almost the whole solar spectrum and generates localized heat at the surface, which is beneficial for water evaporation. Its water evaporation rate is 6.6 times higher than that of pure water. It has a stable cyclic performance over ten cycles under the illumination of simulated sunlight (500 W Xe lamp). Its flexibility makes it easy to reuse and transfer, which is evaluated by the bending deformation test. The W18O49/carbon foam composite is a prospective material in solar energy conversion field, and the preparation procedure is feasible to scale‐up. [ABSTRACT FROM AUTHOR]