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.

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.

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.

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 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.

Metal-organic frameworks constructed from versatile [WS4Cu(x)](x-2) units: micropores in highly interpenetrated systems.

Five metal-organic frameworks (MOFs) formed by [WS(4)Cu(x)](x-2) secondary building units (SBUs) and multi-pyridyl ligands are presented. The [WS(4)Cu(x)](x-2) SBUs function as network vertexes showing various geometries and connectivities. Compound 1 contains one-dimensional channels formed in fourfold interpenetrating diamondoid networks with a hexanuclear [WS(4)Cu(5)](3+) unit as SBU, which shows square-pyramidal geometry and acts as a tetrahedral node. Compound 2 contains brick-wall-like layer also with a hexanuclear [WS(4)Cu(5)](3+) unit as SBU. The [WS(4)Cu(5)](3+) unit in 2 is a new type of [WS(4)Cu(x)](x-2) cluster unit in which the five Cu(+) ions are in one plane with the W atom, forming a planar unit. Compound 3 shows a nanotubular structure with a pentanuclear [WS(4)Cu(4)](2+) unit as SBU, which is saddle-shaped and acts as a tetrahedral node. Compound 4 contains large cages formed between two interpenetrated (10,3)-a networks also with a pentanuclear [WS(4)Cu(4)](2+) unit acting as a triangular node. The [WS(4)Cu(4)](2+) unit in 4 is isomeric to that in 3 and first observed in a MOF. Compound 5 contains zigzag chains with a tetrahedral [WS(4)Cu(3)](+) unit as SBU, which acts as a V-shaped connector. The influence of synthesis conditions including temperature, ligand, anions of Cu(I) salts, and the ratio of [NH(4)](2)WS(4) to Cu(I) salt on the formation of these [WS(4)Cu(x)](x-2)-based MOFs were also studied. Porous MOF 3 is stable upon removal and exchange of the solvent guests, and when accommodating different solvent molecules, it exhibits specific colors depending on the polarity of incorporated solvent, that is, it shows a rare solvatochromic effect and has interesting prospects in sensing applications.

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.

Chiral cyanide-bridged Cr(III)-Mn(III) heterobimetallic chains based on [(Tp)Cr(CN)3]-: synthesis, structures, and magnetic properties.

By the reactions of Mn(III) Schiff-base complexes with the tricyanometalate building block, [(Tp)Cr(CN)(3)](-) (Tp = Tris(pyrazolyl) hydroborate), two couples of enantiomerically pure chiral cyano-bridged heterobimetallic one-dimensional (1D) chain complexes, [Mn((R,R)-Salcy)Cr(Tp)(CN)(3)·1/4H(2)O·1/2CH(2)Cl(2)](n) (1) and [Mn((S,S)-Salcy)Cr(Tp)(CN)(3)·1/4H(2)O·1/2CH(2)Cl(2)](n) (2) (Salcy = N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion), [Mn((R,R)-Salphen)Cr(Tp)(CN)(3)](n) (3) and [Mn((S,S)-Salphen)Cr(Tp)(CN)(3)](n) (4) (Salphen = N,N'-1,2-diphenylethylene-bis(salicylideneiminato) dianion), have been successfully synthesized. Circular dichroism (CD) spectra confirm the enantiomeric nature of the optically active complexes. Structural analyses reveal the formation of neutral cyano-bridged zigzag single chains in 1 and 2, and neutral cyano-bridged zigzag double chains in 3 and 4. Magnetic studies show that antiferromagnetic couplings are operative between Cr(III) and Mn(III) centers bridged by cyanide. Complexes 1 and 2 are the rare examples of chiral ferrimagnets; while complexes 3 and 4 exhibit a coexistence of chirality and spin-glass behavior in a 1D chain.

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.

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.

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.

Solvatochromic behavior of a nanotubular metal-organic framework for sensing small molecules.

A nanotubular metal-organic framework (MOF), {[(WS(4)Cu(4))I(2)(dptz)(3)]·DMF}(n) (dptz = 3,6-di(pyridin-4-yl)-1,2,4,5-tetrazine, DMF = N,N-dimethylformamide) for sensing small solvent molecules is presented. When accommodating different solvent molecules as guests, the resulting inclusion compounds exhibit different colors depending on the solvent guests, and more interestingly, the band gaps of these solvent-included complexes are in linear correlation with the polarity of the guest solvents. The solvent molecules can be sensed by the changes of UV-vis spectra of the corresponding inclusion compounds, showing a new way of signal transduction as a new kind of sensor. The sensing by such a MOF occurs within the channel-containing material rather than on the external surface.

Synthesis and anion sensing of water-soluble metallomacrocycles.

The self-assembly of (TMEDA)Pd(NO(3))(2) or (TMEDA)Pt(NO(3))(2) (where TMEDA = N(1),N(1),N(2),N(2)-tetramethylethane-1,2-diamine) and anthracene- or ferrocene-based diimidazole ligands (L(1-3)) in aqueous solution affords a series of positively charged [M(2)L(2)](4+) dimetallomacrocycles. Their structures were characterized by (1)H NMR and electrospray ionization mass spectrometry and in the cases of {[(TMEDA)Pd](2)L(1)(2)}(NO(3))(4) (1), {[(TMEDA)Pd](2)L(1)(2)}(PF(6))(4) (1a), and {[(TMEDA)Pd](2)L(3)(2)}(NO(3))(4) (4) by single-crystal X-ray diffraction analysis. Interestingly, the NMR spectra of 1 and 1a revealed that the difference of their structures, as confirmed by X-ray diffraction analysis, was that a NO(3)(-) of 1 was encapsulated inside the cavity of the basket-shaped metallomacrocycle by C-H···O hydrogen bonds, while PF(6)(-) of 1a was bound outside by C-H···F hydrogen bonds. The fluorescence titration experiment exhibited the formation of 1:1 host-guest complexation for anthracene-based positively charged [M(2)L(2)](4+)-type metallomacrocycles with NO(3)(-). The interactions between metallomacrocycles and various anions were investigated via fluorescence titration and cyclic voltammetry studies, respectively.

Poly[[aqua-tris-(µ-benzene-1,4-dicarboxyl-ato)tricobalt(II)] methanol monosolvate monohydrate].

The asymmetric unit of the title compound, {[Co(3)(C(8)H(4)O(4))(3)(H(2)O)]·CH(3)OH·H(2)O}(n), consists of four crystallographically independent Co cations, four benzene-1,4-dicarboxyl-ate (bdc) anions, two water and one methanol solvent mol-ecule. Two of the Co cations and two of the bdc anions are located on centres of inversion, whereas all other atoms are located in general positions. In the crystal, two Co atoms are only fourfold coordinated by three O atoms from three bdc ligands and by one O atom from one coordinated water mol-ecule, while a third Co atom is coordinated by four O atoms from four bdc ligands within a strongly distorted tetra-hedral geometry. The other two Co cations are octa-hedrally coordinated by six O atoms from six bdc anions. The Co cations are linked by the bdc anions into a three-dimensional framework. From this arrangement, cavities are formed in which additional methanol and water mol-ecules are embedded.

Poly[[hexa-kis-(µ-benzene-1,4-dicarboxyl-ato)octa-kis-(N,N-dimethyl-acetamide)-hexa-manganese(II)] monohydrate].

In the title compound, {[Mn(6)(C(8)H(4)O(4))(6)(C(4)H(9)NO)(8)]·H(2)O}(n), two of the Mn atoms are six-coordinated by six O atoms from three benzene-1,4-dicarboxyl-ate (bdc) ligands and two trans DMA (dimethyl-acetamide) mol-ecules, whereas two other Mn atoms, located on inversion centers, are both in octa-hedral coordinations by six bdc O atoms. The discrete trinuclear manganese secondary building units (SBU) of Mn(3)(O(2)CR)(6) ({-Mn-Mn-Mn-}) are linked through bdc ligands, forming a chain, while the discrete trinuclear SBU of {-Mn-Mn-Mn-} are bridged, forming another chain]. The two types of chains are linked through bdc ligands, resulting in the formation of a layer with 3(6) topology. Weak O-H⋯O and O-H⋯N hydrogen-bonding inter-actions involving the disordered water molecule (half-occupation) extend the two-dimensional layers into a three-dimensional supra-molecular framework.

Syntheses, structures, and magnetic properties of two kinds of unique heterometallic chains with mixed-bridging ligands of tricyanometalate and alkoxide.

The reactions of copper(II) salts, 1,3-bis(dimethylamino)-2-propanol (bdmapH) or 1,3-bis(amino)-2-propanol (bapH) and [(Tp)Fe(CN)(3)](-) (Tp = tris(pyrazolyl)hydroborate) gave four mixed-bridged heterometallic one-dimensional (1D) coordination polymers, {[(Tp)(2)Fe(2)(CN)(6)(OAc)(bdmap)Cu(2)(H(2)O)]·2H(2)O}(n) (1, HOAc = acetic acid), {[(Tp)(2)Fe(2)(CN)(6)(Pa)(bdmap)Cu(2)(H(2)O)]·2MeCN}(n) (2, HPa = propionic acid), {[(Tp)(2)Fe(2)(CN)(6)(Tfa)(bdmap)Cu(2)(H(2)O)]·2MeCN}(n) (3, HTfa = trifluoroacetic acid), and {[(Tp)(2)Fe(2)(CN)(6)(OAc)(bap)Cu(2)(MeOH)]·2MeOH·H(2)O}(n) (4). Complexes 1-3 show unique branched zigzag chain structures and complex 4 exhibits as a steplike chain. Ferromagnetic interactions between Fe(III) and Cu(II) ions by bridging cyanides are observed in all complexes. Strong antiferromagnetic interactions are presented between the Cu(II) ions in complexes 1-3, whereas similar antiferromagnetic coupling between Cu(II) ions is obviously weakened in complex 4 because of the distortion of penta-coordinated Cu(II) ions.

Porous coordination polymers of transition metal sulfides with PtS topology built on a semirigid tetrahedral linker.

Four novel porous metal sulfide coordination polymers, [M(tpom)S(x)(SH)(y)] x z(H(2)O) (metal-sulfide frameworks, denoted MSF-n, n = 1, Cd; 2, Mn; 3, Fe; 4, Co; x = 0, y = 2 for 1, 2, and 4 and x = 0.54, y = 1.46 for 3), were solvothermally prepared by using a quadridentate linker, tetrakis(4-pyridyloxymethylene)methane (tpom), in the presence of organic sulfur compound under an acidic conditions. MSF-n (n = 1-4) is isostructural and built upon the tetrahedral tpom linker and square planar MS(x)(SH)(y) unit, which form a binodal 4,4-connected porous framework with a 2-fold interpenetrated 4(2)8(4)-pts net. With rectangular pore channels of about 5 x 6 A(2) (interatomic distances between the nearest protruding H atoms across) running along both the crystallographic a and b directions, MSF-n possesses permanent porosity with a BET surface area of 575, 622, 617, and 767 m(2)/g for MSF-1, -2, -3, and -4, respectively, as estimated from N(2) adsorption measurements. MSF-n (n = 1-4) has hydrogen storage capacities of 1.03, 1.37, 1.29, and 1.58 wt % at 77 K and 1 atm, respectively, each corresponding to 2.0 H(2) molecules per unit cell. In addition, MSF-n (n = 1-4) can adsorb 24.1, 25.0, 21.6, and 24.1 wt % of carbon dioxide and 6.0, 6.1, 5.6, and 6.4 wt % of methane, respectively, at room temperature and 20 atm.

Syntheses, structures, and magnetic properties of heterobimetallic clusters with tricyanometalate and pi-conjugated ligands containing 1,3-dithiol-2-ylidene.

Two new pi-conjugated 1,3-dithiol-2-ylidene-containing ligands, 4,5-[1',4']dithiino[2',3'-b]quinoxaline-2-bis(2-pyridyl)methylene-1,3-dithiole (L(1)) and 4,5-bis(methylthio)-2-bis(2-pyridyl)methylene-1,3-dithiole (L(2)), have been synthesized and characterized. Using L(1), L(2), or dimethyl 2-[di(pyridin-2-yl)methylene]-1,3-dithiole-4,5-dicarboxylate (L(3)) as the auxiliary ligand and [(Tp)Fe(CN)(3)](-) or [(i-BuTp)Fe(CN)(3)](-) [Tp = tris(pyrazolyl)borate; i-BuTp = 2-methylpropyltris(pyrazolyl)borate] as the building block, two rectangular-square Fe(2)Ni(2) clusters [(Tp)Fe(CN)(3)Ni(L(1))(2)](2).2ClO(4).6H(2)O (1) and [(i-BuTp)Fe(CN)(3)Ni(L(3))(2)](2).2ClO(4).6H(2)O (2) and two trinuclear clusters [(Tp)(2)Fe(2)(CN)(6)Ni(L(2))(2)].8H(2)O (3) and [(Tp)(2)Fe(2)(CN)(6)Co(L(3))(2)].5H(2)O (4) have been prepared in parallel and structurally characterized. Complexes 1 and 2 show similar square structures, and weaker intermolecular pi-pi-stacking interactions through the pyrazolyl groups of the Tp(-) ligands are observed. 2D sheet structures are formed in complexes 3 and 4 through intermolecular pi-pi-stacking interactions. In 3, shorter S...S contacts further connect the 2D sheets to 3D supramolecular structures. Magnetic studies show intramolecular ferromagnetic coupling in complexes 1-4. Complexes 1 and 2 show obvious frequency dependencies in the alternating-current magnetic susceptibility data, indicating single-molecule-magnet behavior with effective spin-reversal barriers of 8.7 K for 1 and 13.5 K for 2, respectively.

Self-assembly and host-guest interaction of metallomacrocycles using fluorescent dipyrazole linker with dimetallic clips.

By employing diimine ligands coordinated dimetallic clips ([(bpy)2Pd2(NO3)2](NO3)2 or [(phen)2Pd2(NO3)2](NO3)2, where bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) as the corner and anthracene-, naphthalene-, and benzene-based dipyrazolate dianions as the linker, a series of positively charged metallomacrocycles ([M4L2]4+ or [M8L4]8+) have been synthesized through a directed self-assembly method in aqueous solution. Every macrocycle has a cavity to bind solvent molecules or anions. The structures were characterized by elemental analysis, 1H and 13C NMR, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analysis for compound 1 x 4 PF6(-) (1 = {[(bpy)Pd]4L(1)2}4+), 3 x 4 PF6(-) x 8 CH3CN x H2O (3 = {[(bpy)Pd]4L(2)2}4+), and 7 x 4 PF6(-) x 6 H2O (7 = {[(bpy)Pd]4L(5)2}4+). The 1:1 host-guest complexation for anthracene-based dipyrazolate-bridged macrocycles with aromatic guests was investigated via UV-vis and fluorescent titration.

A tetra-nuclear cobalt(III) cluster with 2-(hydroxy-meth-yl)pyridine ligands.

In the title compound, tetra-kis[µ(3)-(2-pyrid-yl)methano-lato]tetra-kis[bromido(methanol)cobalt(III)] tetra-bromide 2-(hydroxy-meth-yl)pyridine tetra-solvate dihydrate, [Co(4)Br(4)(C(6)H(6)NO)(4)(CH(3)OH)(4)]Br(4)·4C(6)H(7)NO(4)·2H(2)O, the cation comprises a [Co(4)O(4)] cubane-type core ( symmetry). The four Co(III) ions and bridging O atoms from four (2-pyrid-yl)methano-late anions are located at alternating vertices of the cube, with bromide ions and methanol ligands on the exterior of the core, completing a distorted octa-hedral geometry. The structure is stablized by inter-molecular O-H⋯Br and O-H⋯O inter-actions.