A route to metalloligands consolidated silver nanoclusters by grafting thiacalix[4]arene onto polyoxovanadates.

Metalloligands provide a potent strategy for manipulating the surface metal arrangements of metal nanoclusters, but their synthesis and subsequent installation onto metal nanoclusters remains a significant challenge. Herein, two atomically precise silver nanoclusters {Ag14[(TC4A)6(V9O16)](CyS)3} (Ag14) and {Ag43S[(TC4A)2(V4O9)]3(CyS)9(PhCOO)3Cl3(SO4)4(DMF)3·6DMF} (Ag43) are synthesized by controlling reaction temperature (H4TC4A = p-tert-butylthiacalix[4]arene). Interestingly, the 3D scaffold-like [(TC4A)6(V9O16)]11- metalloligand in Ag14 and 1D arcuate [(TC4A)2(V4O9)]6- metalloligand in Ag43 exhibit a dual role that is the internal polyoxovanadates as anion template and the surface TC4A4- as the passivating agent. Furthermore, the thermal-induced structure transformation between Ag14 and Ag43 is achieved based on the temperature-dependent assembly process. Ag14 shows superior photothermal conversion performance than Ag43 in solid state indicating its potential for remote laser ignition. Here, we show the potential of two thiacalix[4]arene modified polyoxovanadates metalloligands in the assembly of metal nanoclusters and provide a cornerstone for the remote laser ignition applications of silver nanoclusters.

RSK2 promotes melanoma cell proliferation and vemurafenib resistance via upregulating cyclin D1.

BRAF inhibitors are commonly used in targeted therapies for melanoma patients harboring BRAFV600E mutant. Despite the benefit of vemurafenib therapy, acquired resistance during or after treatment remains a major obstacle in BRAFV600E mutant melanoma. Here we found that RSK2 is overexpressed in melanoma cells and the high expression of RSK2 indicates poor overall survival (OS) in melanoma patients. Overexpression of RSK2 leads to vemurafenib resistance, and the deletion of RSK2 inhibits cell proliferation and sensitizes melanoma cells to vemurafenib. Mechanistically, RSK2 enhances the phosphorylation of FOXO1 by interacting with FOXO1 and promoting its subsequent degradation, leading to upregulation of cyclin D1 in melanoma cells. These results not only reveal the presence of a RSK2-FOXO1-cyclin D1 signaling pathway in melanoma, but also provide a potential therapeutic strategy to enhance the efficacy of vemurafenib against cancer.

HOTTIP polymorphism may affect gastric cancer susceptibility by altering HOTTIP expression.

BACKGROUND: Non-coding RNA polymorphisms can affect disease risk and prognosis by influencing gene expression. Here, we first investigated the association between single nucleotide polymorphisms (SNPs) of long non-coding RNA (lncRNA) HOTTIP and gastric cancer risk/prognosis. METHODS: A total of five HOTTIP SNPs among 627 gastric cancer cases and 935 controls were tested by Kompetitive Allele Specific PCR (KASP) assay. The functional SNPs underwent eQTL analysis and the expression of HOTTIP was assessed by quantitative RT-PCR. RESULTS: The rs2067087 and rs3807598 SNPs of HOTTIP increased susceptibility to gastric cancer (rs2067087: dominant model, P=0.008, odds ratio (OR) = 1.35; rs3807598: recessive model, P=0.037, OR = 1.29). Both HOTTIP rs2067087 and rs3807598 could affect the expression of mature lncRNA (P=0.003 and P=0.032, respectively). CONCLUSION: The rs2067087 and rs3807598 SNPs of HOTTIP are associated with gastric cancer risk, possibly by affecting the expression of mature HOTTIP.

Electrospinning Ag-TiO2 Nanorod-Loaded Air Treatment Filters and Their Applications in Air Purification.

The efficient treatment of the problem of air pollution is a practical issue related to human health. The development of multi-functional air treatment filters, which can remove various kinds of pollutants, including particulate matter (PM) and organic gases, is a tireless pursuit aiming to address the actual needs of humans. Advanced materials and nano-manufacturing technology have brought about the opportunity to change conventional air filters for practical demands, with the aim of achieving the high-efficiency utilization of photons, a strong catalytic ability, and the synergetic degradation of multi-pollutants. In this work, visible-responding photocatalytic air treatment filters were prepared and combined with a fast and cost-effective electrospinning process. Firstly, we synthesized Ag-loaded TiO2 nanorod composites with a controlled size and number of loaded Ag nanoparticles. Then, multi-functional air treatment filters were designed by loading catalysts on electrospinning nanofibers combined with a programmable brush. We found that such Ag-TiO2 nanorod composite-loaded nanofibers displayed prominent PM filtration (~90%) and the degradation of organic pollutants (above 90%). The superior performance of purification could be demonstrated in two aspects. One was the improvement of the adsorption of pollutants derived from the increase of the specific surface area after the loading of catalysts, and the other was the plasmonic hot carriers, which induced a broadening of the optical absorption in the visible light range, meaning that many more photons were utilized effectively. The designed air treatment filters with synergistic effects for eliminating both PM and organic pollutants have promising potential for the future design and application of novel air treatment devices.

Structural isomerism in gold nanoparticles revealed by X-ray crystallography. [Corrected].

Revealing structural isomerism in nanoparticles using single-crystal X-ray crystallography remains a largely unresolved task, although it has been theoretically predicted with some experimental clues. Here we report a pair of structural isomers, Au38T and Au38Q, as evidenced using electrospray ionization mass spectrometry, X-ray photoelectron spectroscopy, thermogravimetric analysis and indisputable single-crystal X-ray crystallography. The two isomers show different optical and catalytic properties, and differences in stability. In addition, the less stable Au38T can be irreversibly transformed to the more stable Au38Q at 50 °C in toluene. This work may represent an important advance in revealing structural isomerism at the nanoscale.

Enantiopure heterobimetallic single-chain magnets from the chiral Ru(III) building block.

A pair of one-dimensional enantiomers based on the versatile chiral dicyanoruthenate(III) building block have been synthesized and they are chiral single-chain magnets with the effective spin-reversal barrier of 28.2 K.

Calix[4]arene-supported mononuclear lanthanide single-molecule magnet.

Three new single paramagnetic lanthanide-based complexes, [Ln(L)(LOEt)] (Ln(3+) = Dy(3+), Tb(3+), and Ho(3+)), are synthesized with the multidentate calix[4]arene ligand H2L (H2L = 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,27-dihydroxy-26,28-dimethoxycalix[4]arene) and Kläui's tripodal ligand LOEt(-) (LOEt(-) = (η(5)-cyclopentadienyl)tris(diethylphosphito-p)cobaltate(III)). All of the complexes have been characterized by single crystal X-ray diffraction analysis, thermal stability, absorption spectra, and magnetization measurements. The magnetic properties and magnetostructural correlation in this seven-coordinated system are investigated. The dysprosium complex 1 shows typical single-molecule magnetic behavior with characteristic magnetic hysteresis loops and the slow relaxation of magnetization.

Seven-coordinate lanthanide sandwich-type complexes with a tetrathiafulvalene-fused Schiff base ligand.

Three seven-coordinate lanthanide(III) sandwich-type mononuclear complexes with π-conjugated TTF-Schiff base ligand H2L (L(2-) = 2,2'-((2-(4,5-bis(methylthio)-1,3-dithiol-2-ylidene)-1,3-benzodithiole-5,6-diyl)bis(nitrilomethylidyne)bis(4-chlorophenolate)) and the tripodal ligand L(OEt)(-) (L(OEt)(-) = [(η(5)-C5H5)Co(P(═O)(OEt)2)3](-)), [(L(OEt))Ln(L)]·0.25H2O (Ln(3+) = Dy(3+), 1; Tb(3+), 2; Ho(3+), 3), have been synthesized and structurally characterized. All of the complexes are also characterized by absorption spectra and electrochemical, spectroelectrochemical, and magnetic studies. The Dy complex exhibits the field-induced slow relaxation of magnetization with an energy barrier of 41.6 K, indicating it shows single lanthanide-based SMM behavior. Introduction of the redox-active TTF unit into the sandwich-type lanthanide(III) complexes with interesting magnetic properties renders them promising for elaboration of new hybrid inorganic-organic materials.

A sandwich-type triple-decker lanthanide complex with mixed phthalocyanine and Schiff base ligands.

A new triple-decker dinuclear sandwich-type dysprosium complex based on both the phthalocyanine ligand and the tetradentate Schiff base ligand was synthesized, which is of interest for synthetic chemistry and also shows single-molecule magnetic behaviour.

Syntheses, structures, and magnetic properties of seven-coordinate lanthanide porphyrinate or phthalocyaninate complexes with Kläui's tripodal ligand.

A series of seven-coordinate mononuclear lanthanide(III) complexes of the general formula [(TPP)Ln(L(OEt))]·0.25H2O and [(Pc)Ln(L(OEt))] (Ln(3+) = Dy(3+), Tb(3+), Ho(3+), and Gd(3+); TPP = 5,10,15,20-tetraphenylporphyrinate; Pc = phthalocyaninate; L(OEt)(-) = [(η(5)-C5H5)Co(P(=O)(OEt)2)3](-)) are synthesized on the basis of the tripodal ligand L(OEt)(-) and either porphyrin or phthalocyanine ligands. All of the complexes are characterized by X-ray crystallography and by static and dynamic magnetic measurements. The Dy and Tb complexes show the field-induced slow relaxation of magnetization, and they are interesting seven-coordinate single-lanthanide-based SMMs. The magnetic relaxation properties of these double-decker sandwich complexes are influenced by the local molecular symmetry and are sensitive to subtle distortions of the coordination geometry of the paramagnetic lanthanide ions, such as metal-to-plane distances, plane center distances, and bending angles.

A giant metallo-supramolecular cage encapsulating a single-molecule magnet.

A giant metallo-supramolecular cage encapsulating a single-molecule magnet, [Ag42{Ho(W5O18)2}(t-BuC≡C)28Cl4]OH, is prepared and structurally characterized. It shows an interesting "peanut-like" structure and remains intact in solution as demonstrated by NMR studies.

Self-assembly of metallomacrocycles with dipyrazole ligands and anion sensing of [Pd4Fe2] macrocycle with ferrocene-based dipyrazole ligand.

By employing dipalladium corners [(bpy)(2)Pd(2)(NO(3))(2)](NO(3))(2) or [(phen)(2)Pd(2)(NO(3))(2)](NO(3))(2) (where bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline) to bridge ferrocene-based dipyrazole ligand (L(1)) and m-phenylene-based dipyrazole ligands (L(2-3)) in aqueous solution, a series of positively-charged [M(4)L(2)](4+) metallomacrocycles were obtained. Their structures were characterized by (1)H NMR, electrospray ionization mass spectrometry (ESI-MS), elemental analysis, and single crystal X-ray diffraction analysis for 1·4NO(3) ({[(bpy)Pd](4)L(1)(2)}(NO(3))(4)) and 4·4NO(3) ({[(phen)Pd](4)L(2)(2)}(NO(3))(4)). In their single crystal structures, NO(3)(-) anions are located at the dipalladium corners by C-H...O hydrogen bonds. Importantly, the anion-sensing properties of ferrocene functionalized [Pd(4)Fe(2)] hetero-metallomacrocycle 1 were investigated in acetonitrile by SWV, CV and NMR analysis, showing promise for Br(-) sensing.

Chiral one-dimensional O-P-O bridged Mn(III)-Schiff base complexes.

Two couples of enantiomerically pure metal phosphonates are successfully synthesized by using chiral Mn(III)-Schiff base mononuclear precursors. Compounds [Mn((R,R)-5-Brsalcy)(2-FC(6)H(4)PO(3)H)]·3H(2)O (1) and [Mn((R,R)-5-Brsalcy)(4-CH(3)C(6)H(4)PO(3)H)]·CH(3)OH·H(2)O (3) [5-Brsalcy = N,N'-(1,2-cyclohexanediylethylene)bis(5-bromosalicylideneiminato) dianion] are isostructural and show similar one-dimensional chain structures where the Mn((R,R)-5-Brsalcy)(+) species are bridged by O-P-O units. Compounds 2 and 4 are (S,S)-enantiomers of 1 and 3, respectively. These compounds are all optically active, exhibiting second harmonic generation responses 0.3 times that of urea. The magnetic measurements of 1 and 3 reveal that dominant antiferromagnetic interactions are mediated between the Mn(III) centers.

Solvent-induced single-crystal-to-single-crystal transformation in multifunctional chiral dysprosium(III) compounds.

Two new enantiomeric ionic chiral dysprosium(III) compounds were designed and synthesized. These compounds show simultaneously the optical activity, ferroelectric effects, nonlinear-optical effects, and slow magnetic relaxation behavior. More interestingly, these compounds exhibit reversible single-crystal-to-single-crystal transformations associated with the release or absorption of solvent molecules. The structure transformations are accompanied by distinct changes in the physical properties.

A racemic polar cobalt phosphonate with weak ferromagnetism.

Comfortably nemp: A novel polar compound [Co(2)(nemp)(2)(H(2)O)(2) ] incorporating racemic [1-(1-naphthyl)ethylamino]methylphosphonate (nemp(2-)) as a ligand is reported (see packing structure). This compound shows nonlinear optical properties at room temperature and weak ferromagnetism below 2 K.

Formation of stable iron/cobalt NHC complexes via unexpected ring opening and in situ generation of a tridentate ligand.

The reactions of FeCl(2) and CoCl(2) with a bistriazolium salt yields the NHC complexes [Fe(III)(L1)(2)]I·H(2)O, [Fe(III)(L2)(2)]PF(6)·CH(3)CN and [Co(III)(L1)(2)]I·0.5CH(3)CN, through an unusual ring opening of one of the triazoyl rings, which leads to the formation of C,N,O tridentate ligands L1 or L2. Furthermore, a Fe(ii) species [Fe(II)(L1)(2)]·CH(2)Cl(2) was also obtained.

Field-induced slow magnetic relaxation in chiral seven-coordinated mononuclear lanthanide complexes.

Four couples of enantiomerically pure chiral seven-coordinated mononuclear lanthanide complexes, [(L(OEt))Dy((R,R)-Salphen)](2)·3H(2)O (1, L(OEt) = [(Cp)Co(P(O)(OEt)(2))(3)], Cp = cyclopentadiene, Salphen = N,N'-1,2-diphenylethylenebis(salicylideneiminato) dianion), [(L(OEt))Dy((S,S)-Salphen)](2)·3H(2)O (2), [(L(OEt))Dy((R,R)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (3, Salcy = N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion), [(L(OEt))Dy((S,S)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (4), [(L(OEt))Tb((R,R)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (5), [(L(OEt))Tb((S,S)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (6), [(L(OEt))Ho((R,R)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (7) and [(L(OEt))Ho((S,S)-5-Cl-Salcy)]·CH(3)OH·1/8H(2)O (8), have been successfully synthesized by using tetradentate chiral salen-type ligands and the Kläui's tripodal ligand of L(OEt). Structural analyses reveal that all compounds have a typical double-decker sandwich structure, and the Ln(iii) ions exhibit a rare seven-coordinated mode, situating in a distorted monocapped triangular prism polyhedron. Circular dichroism (CD) spectra confirm the enantiomeric nature of the optically active complexes and demonstrate that the chirality is successfully transferred from the ligand to the coordination environment of the Ln(iii) ions. Field-induced slow relaxation of the magnetization is observed for complexes 1-4, suggesting that they can be rare chiral single-ion magnets (SIMs) based on the seven-coordinated lanthanide ions.

Lanthanide-ion-tuned magnetic properties in a series of three-dimensional cyano-bridged Ln(III)W(V) assemblies.

The reaction of [W(CN)(8)](3-) with Ln(3+) and pyrazine in acetonitrile yielded a series of isostructural compounds formulated as Ln(H(2)O)(4)(pyrazine)(0.5)W(CN)(8) (Ln = La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7)). The Ln(III) and W(V) centers in the structure are linked through cyanide groups to form two-dimensional (2D) layers, which are further pillared by pyrazine, generating 3D frameworks. The magnetic behavior for compounds 1-7 were driven by the lanthanide ions involved. The Ln(III) and W(V) ions in compounds 2 and 5 are ferromagnetically coupled with magnetic ordering occurring at 2.8 K, comparable with magnetic ordering with the critical temperature of 1.9 K for compound 4. In addition, the antiferromagnetic interactions were observed in compounds 3 and 7, while no significant magnetic couplings were found in compounds 1 and 6.

Vibrational and electronic circular dichroism monitoring of copper(II) coordination with a chiral ligand.

Novel copper(II) coordination compounds with chiral macrocyclic imine ligands derived from R-/S-camphor were asymmetrically synthesized and characterized with the aid of chiroptical spectroscopies. Crystal structures of both enantiomers were determined by single crystal X-ray diffraction analysis. Circular dichroism (CD) spectra were analyzed using a simplified exciton model as well as quantum chemical computations. The absolute configuration of the copper(II) coordination compounds determined from CD was found consistent with the crystal data. The copper(II) complexes were further investigated by vibrational CD (VCD) measurement combined with density functional theory calculation. The complex formation was evidenced by spectral shifts of the characteristic bands in the CD and VCD spectra.