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AbstractMelanoma poses a challenge in oncology because of its aggressive nature and limited treatment modalities. The tumour microenvironment (TME) in melanoma contains unique properties such as an immunosuppressive and high-density environment, unusual vasculature, and a high number of stromal and immunosuppressive cells. In recent years, numerous experiments have focused on boosting the immune system to effectively remove malignant cells. Adjuvants, consisting of phytochemicals, toll-like receptor (TLR) agonists, and cytokines, have shown encouraging results in triggering antitumor immunity and augmenting the therapeutic effectiveness of anticancer therapy. These adjuvants can stimulate the maturation of dendritic cells (DCs) and infiltration of cytotoxic CD8+ T lymphocytes (CTLs). Furthermore, nanocarriers can help to deliver immunomodulators and antigens directly to the tumour stroma, thereby improving their efficacy against malignant cells. The remodelling of melanoma TME utilising phytochemicals, agonists, and other adjuvants can be combined with current modalities for improving therapy outcomes. This review article explores the potential of adjuvants, drugs, and their nanoformulations in enhancing the anticancer potency of macrophages, CTLs, and natural killer (NK) cells. Additionally, the capacity of these agents to repress the function of immunosuppressive components of melanoma TME, such as immunosuppressive subsets of macrophages, stromal and myeloid cells will be discussed. [ABSTRACT FROM AUTHOR]

Abstract Background Methods Results Conclusions There is a lack of actual and comprehensive data on the detection rate of neuronal surface antibodies in patients with unexplained epilepsy in China. Thus, we attempted to analyze the differences in clinical manifestations, cerebrospinal fluid (CSF) characteristics, seizure types and other aspects of antibody-positive and negative patients, to identify suspected antibody-positive epilepsy patients.In total, 137 inpatients with unexplained epilepsy were consecutively included, and neuronal surface antibodies (NSAbs) were detected by serological and/or CSF evaluations. The clinical features and seizure characteristics were analyzed between the NSAb-positive and negative patients. In addition, patients were divided into four groups based on CSF and blood antibody titers. CSF cell count and protein content were analyzed in relation to antibody titers.There were 45 (32.8%) patients tested positive for antibodies. Multivariate analyses revealed that age, mental status changes or memory deterioration, CSF protein, CSF cell count, treatment, days of hospitalization, outcome, duration of symptoms before hospitalization, status epilepticus, and number of antiepileptic drugs were significantly associated with the NSAb-positive group and changes in inflammatory indicators in routine CSF analysis were associated with antibody titers.A relatively high proportion of patients with unexplained epilepsy have positive NSAbs. Patients with the above clinical characteristics need to be highly suspected of NSAbs positivity and should be tested for antibodies in time to assist treatment. The decrease of CSF cell count and protein content has suggestive value for the decrease of antibody titer, which should be evaluated in the follow-up. [ABSTRACT FROM AUTHOR]

Two isostructural organic-inorganic hybrid ruthenium-containing polyoxometalates (POMs), NaH5[(P2M18O62)]·(Ru(dmso)4Cl2)4·nH2O (M = W, n = 12 (1); M = Mo, n = 10 (2)), have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric (TG) analyses, and elemental analyses. Single-crystal X-ray diffraction analyses indicate that they are co-crystals and that the two polyoxoanions are structurally similar aside from the identity of the metal ions present. Furthermore, the electrochemical behavior of the POMs was investigated in aqueous solution to establish the redox properties associated with having W versus Mo in the structures. [ABSTRACT FROM AUTHOR]

Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements, optimal ground sampling should be made to increase the representativeness of in situ observations. Therefore, many ground sampling strategies have been proposed, but their performance within the coarse pixel has not been evaluated. Hence, this study evaluated four typical methods regarding their ability to obtain pixel scale ground 'truth'. Random combination (RC) performs best, with the always fewest samples to satisfy representativeness errors (REs) of 3% in the case of a small number of samples. When the goal of sampling is to obtain in situ measurements with REs close to 0 at the expense of increasing the number of samples, cumulative representativeness sampling (CRS) is more effective than RC in less heterogeneous areas. Geo-statistical model-based sampling (GSS) does not work well because the number of samples within the coarse pixel scale cannot support a robust semi-variogram model. Stratified sampling (SS) is highly dependent on spatial heterogeneity and does not work well in the case of small sample sizes. This study gives important guidance for ground sample deployment within the coarse pixel for validation of coarse-resolution satellite albedo products over a heterogeneous surface. [ABSTRACT FROM AUTHOR]

High viability and further adipogenic differentiation of adipose-derived stem cells (ADSCs) are fundamental for engraftment and growth of the transplanted adipose tissue. It has been demonstrated that extracellular matrix (ECM) regulates cell proliferation and differentiation by interacting with ERK1/2 signalling pathway. In this study, we prepared autologous decellularized extracellular matrix (d-ECM) and explored its effect on the proliferation and adipogenic ability of ADSCs in low serum culture. We found that 2% foetal bovine serum (FBS) in growth medium inhibited cell viability and DNA replication, and decreased mRNA and protein levels of PPARγ and C/EPBα compared with 10% FBS. Correspondingly, after 14-days adipogenic induction, cells cultured in 2% FBS possessed lower efficiency of adipogenesis and expressed less adipocyte differentiation markers ADIPOQ and aP2. On the contrary, the d-ECM-coated substrate continuously promoted the expression of PPARγ, and regulated the phosphorylation of ERK1/2 in different manners during differentiation. Pretreatment with ERK1/2 inhibitor PD98059 neutralized the effects of d-ECM, which suggested d-ECM might regulate the adipogenesis of ADSCs through ERK1/2-PPARγ pathway. In addition, d-ECM was revealed to regulate the transcription and expression of stemness-associated genes, such as OCT4, NANOG and SOX2, in the undifferentiated ADSCs, which might be related to the initiation of differentiation. [ABSTRACT FROM AUTHOR]

A high-nuclearity nickel-substituted polyoxotungstate, Na6K5.5H4.5 {[Ni8(OH)6(H2O)2](CO3)3(SiW9O34)2}·22H2O (1), has been obtained by the reaction of Na10[α-SiW9O34]·18H2O, Ni(NO3)2·6H2O and K2CO3 in aqueous solution and characterized by IR spectroscopy, single crystal X-ray diffraction, thermal gravimetric analysis and elemental analysis. Carbonate is not only used to adjust the pH of the solution, but also is a structure-stabilizing agent. The polyoxoanion {[Ni8(OH)6(H2O)2](CO3)3(SiW9O34)2}16- (1a) can be regarded as two {[Ni4(OH)3(H2O)](SiW9O34)} subunits connected by three carbonate groups, which represents the first polyanion containing an octanuclear nickel cluster based on trivacant Keggin-type polyoxotungstate {XW9} (X = heteroatom). The subunit {[Ni4(OH)3(H2O)](SiW9O34)} can be viewed as a tetranuclear nickel cluster linked to a trivacant Keggin-type polyoxotungstate {SiW9O34}. Furthermore, magnetic measurements show that 1 exhibits antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

A rare monocapped trivacant Keggin fragment [A-α-AsIIIAsVMo9O34]6–has been captured and an organic-inorganic hybrid arsenomolybdate (H2en)[Ni(en)2(H2O)]{[Ni(en)2][AsIIIAsVMo9O34]}∙3H2O (1) was obtained under hydrothermal conditions. The structure of 1 was determined by X-ray single-crystal diffraction and further characterized by IR spectroscopy, X-ray powder diffraction (XRPD), scanning electron microscope with energy dispersive X-ray (EDX-SEM) and X-ray photoelectron spectroscopy (XPS). Single-crystal structural analysis indicates that 1 contains the peculiar monocapped trivacant [A-α-AsIIIAsVMo9O34]6–fragment derived from the rare trivacant Keggin type [A-α-AsVMo9O34]9–unit capped by a triangular pyramidal {AsO3} group.1represents the first Ni-substituted inorganic-organic arsenomolybdate containing the [A-α-AsIIIAsVMo9O34]6–subunit. [ABSTRACT FROM AUTHOR]

An organic–inorganic coplanar-shaped hexa-CuII sandwiched hybrid, (H2en){[Cu(en)2]2[Cu2(en)2Cu4(H2O)2](B-α-AsW9O34)2} · 5H2O (en = ethylenediamine) (1), has been synthesized via hydrothermal method and further characterized by IR spectroscopy, thermogravimetric analysis, and X-ray single-crystal diffraction. Single-crystal X-ray diffraction analysis shows that 1 contains an organic–inorganic hybrid polyoxoanion {Cu2(en)2Cu4(H2O)2(B-α-AsW9O34)2}6−, which can be described as a coplanar-shaped hexa-CuII cluster sandwiched by two trivacant [B-α-AsW9O34]9− fragments. Complex 1 represents a rare organic–inorganic coplanar-shaped hexa-CuII cluster sandwiched arsenotungstate. Magnetic susceptibility measurements indicate that 1 demonstrates ferromagnetic coupling interactions within the CuII centers. [ABSTRACT FROM PUBLISHER]

A new organic–inorganic hybrid polyoxoniobate [Cu(1,3-dap)2(H2O)][(H6Nb6O19)2Cu(1,3-dap)2] · 4(1,3-dap)·20H2O (1) (1,3-dap = 1,3-diaminopropane) has been synthesized by the diffusion method and structurally characterized by elemental analyses, infrared spectrum, ultraviolet spectroscopy, and single crystal X-ray diffraction. Crystal structure analysis reveals that 1 consists of a dimeric dumbbell anion [(H6Nb6O19)2Cu(1,3-dap)2]2−, a copper coordinated cation, four 1,3-dap ligands and 20 crystal water molecules. Neighboring units are combined via hydrogen bonds forming a 3-D supramolecular framework. [ABSTRACT FROM AUTHOR]

A new organic-inorganic hybrid polyoxoniobate (H2en)2[Ni(en)3][H2Nb6O19] · 5.5H2O (1) (en = ethylenediamine) has been synthesized by the diffusion method and structurally characterized by elemental analyses, infrared spectrum, ultraviolet (UV) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction, thermogravimetric (TG) analysis, and single-crystal X-ray diffraction. Crystal structure analysis reveals that 1 exhibits a 3-D supramolecular architecture constructed from Lindqvist-type [H2Nb6O19]6- polyoxoanions and [Ni(en)3]2+ via hydrogen-bonding interactions. The XPS measurement indicates that the oxidation state of Ni is +2. TG curve of 1 exhibits two steps of weight loss. In situ UV spectra display that 1 can exist in large pH range in aqueous solution. [ABSTRACT FROM AUTHOR]

Two new organic-inorganic composite sandwich-type arsenotungstates [H2dap]6H8[Ni4(H2O)2(B-α-AsW9O34)2]2 · 33H2O (1) and {[Ni(dap)2(H2O)]2[Ni(dap)2]2[Ni4(Hdap)2(B-α-AsW9O34)2]} · 4H2O (2) (dap = 1,2-diaminopropane) have been hydrothermally synthesized by reaction of Na8[A-α-HAsW9O34] · 11H2O with NiCl2 · 6H2O in the presence of 1,2-diaminopropane and characterized by elemental analysis, IR spectra, X-ray single-crystal diffraction, and thermogravimetric analysis. 1 crystallizes in the triclinic P1 space group with a = 16.351(6) Å, b = 16.423(6) Å, c = 19.894(7) Å, α = 110.630(6)°, β = 92.684(7)°, γ =104.946(7)°, V = 4774(3) Å3, Z = 1, GOOF = 1.033, R1 = 0.0517, wR2 = 0.1086. 2 also crystallizes in the triclinic P1 space group with a = 13.305(4) Å, b = 13.882(4) Å, c = 17.031(5) Å, α = 68.109(5)°, β = 71.511(4)°, γ = 88.407(5)°, V = 2753.5(14) Å3, Z = 1, GOOF = 1.051, R1 = 0.0491, wR2 = 0.1150. Notably, 1 is a discrete structure, composed of two tetra-NiII substituted sandwich-type polyoxoanions [Ni4(H2O)2(B-α-AsW9O34)2]10- with different spatial orientation, whereas 2 displays a organic-inorganic composite 2-D sheet architecture constructed by tetra-NiII sandwiched [Ni4(H2O)2(B-α-AsW9O34)2]10- units by means of [Ni(dap)2]2+ bridges. Some previously reported transition-metal-substituted sandwich-type polyoxotungstates have been summarized. [ABSTRACT FROM AUTHOR]

Two new hybrid Dawson-based polyoxotungstates, [Mn(2,2'-bipy)3]H2[Mn(2,2'-bipy)2][P2W18O62] (1) and [Co(H2biim)3)]2H2[P2W18O62] · 8H2O (2) (2,2'-bipy = 2,2'-bipyridine, H2biim = 2,2'-biimdazole), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectra. Compound 1 is a 1-D zigzag chain constructed from alternate Dawson-type heteropolyanions [α-P2W18O62]6- and metal coordination cations [Mn(2,2'-bipy)2]2+, in which the 1-D chains are extended into a 3-D framework through C-H ··· π and π-π stacking interactions. Compound 2 is a discrete structure consisting of [α-P2W18O62]6- and two [Co(H2biim)3)]2+ cations, forming a 3-D supramolecular framework via N-H ··· O hydrogen bonds and C-H ··· π interactions. Photoluminescence properties of 1 and 2 have been investigated at room temperature. [ABSTRACT FROM AUTHOR]

Two new copper-phosphotungstate complexes [CuII(1,3-dap)2]2[CuII(1,3-dap)]2H[α-PW10.5 [image omitted]O40] (1) and [CuI(phen)2]3[α-PW12O40] (2) (1,3-dap = 1,3-diaminopropane, phen =1,10-phenanthroline) have been synthesized and characterized by elemental analyses, IR spectroscopy, UV spectroscopy, thermogravimetric analyses, fluorescence spectroscopy, X-ray photoelectron spectroscopy, and single-crystal X-ray diffraction. Single-crystal diffraction analyses indicate that both 1 and 2 consist of a saturated α-Keggin phosphotungstate fundamental building unit as polyoxoanions and several metal-organic moieties as countercations. In 1, two [Cu(1,3-dap)]2+ complex cations are capped on the polyoxoanion [PW10.5 [image omitted]O40]9- through four bridging oxygens and the other two [Cu(1,3-dap)2]2+ coordination cations are grafted on the terminal oxygens of the polyoxoanion, whereas in 2, three [Cu(phen)2]2+ complex cations are discrete. Fluorescence reveals that 2 exhibits a broad emission band at 437 nm upon excitation at 380 nm. [ABSTRACT FROM AUTHOR]

Two new organic-inorganic hybrid cobalt-molybdovanadates [Co(phen)3]H2[H2V2Mo6O26] · 7H2O (1) and [Co(2,2'-bipy)3][Na(H2O)7][VMo12O40] (2) have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, UV, XPS spectroscopy, thermogravimetric (TG) analyses, and X-ray single crystal diffraction. The molecular structure of 1 consists of a [V2Mo6(OH)2O24]4- polyoxoanion, a [Co(phen)3]2+, two H+ and seven lattice water molecules. The structure of [V2Mo6(OH)2O24]4- consists of six MoO6 octahedra and two VO4 tetrahedra; six MoO6 octahedra are linked by edge-sharing oxygens forming a {Mo6} ring, and two VO4 tetrahedra cap opposite sides of the {Mo6} ring. The molecular structural unit of 2 is constructed from a typical Keggin-type [VMo12O40]3- polyoxoanion and a [Co(2,2'-bipy)3]2+ cation and a Na+ countercation; Co2+ is coordinated by six nitrogens from three 2,2'-bipyridines forming a distorted octahedron. [ABSTRACT FROM AUTHOR]

Two new inorganic-organic hybrid polyoxotungstates [enH2][C8N4H22]3H2[Co4(enH)2(GeW9O34)2] · 6H2O (1) and [Co(en)3]2H6[Co4(enH)2(GeW9O34)2] · 14H2O (2) (en = ethylenediamine) have been synthesized by hydrothermal methods and characterized by IR, TG, XRD, XPS, elemental analysis, and single-crystal X-ray analysis. The polyoxoanion frameworks of the two compounds consist of two classical tetra-Co sandwiched polyoxoanions [Co4(H2O)2(GeW9O34)2] in which two organic ligands substitute two water molecules. The tetra-Co clusters in 1 and 2 exhibit the familiar structural type of a β-junction at the sites of metal incorporation. Compound 1 is of interest owing to its C8N4H20 ligands resulting from the reaggregation of triethylenetetramine which occurs under 160°C. [ABSTRACT FROM AUTHOR]

Two organic-inorganic hybrid polyoxometalates {[V2W4O19{Cu(2,2'-bipy)2}2] · (4,4'-bipy)}n (1) and [Co(2,2'-bipy)3][W6O19] · H2O (2) (2,2'-bipy = 2,2'-bipyridine, 4,4'-bipy = 4,4'-bipyridine), constructed by Lindqvist polyanions and transition metal coordination cations, have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, UV spectra, thermogravimetric (TG) analyses, X-ray photoelectron spectroscopy (XPS), and single- crystal X-ray diffraction. Compound 1 is a neutral molecule and consists of a di-VV substituted Lindqvist-type polyanion [V2W4O19]4-, two supporting copper cations [Cu(2,2'-bipy)2]2+ and one free 4,4'-bipy. Neutral molecules of 1 are extended to a 2-D grid-like network by π-π stacking interactions between pyridine groups. The molecular structure of 2 contains one [W6O19]2- cluster polyanion and a [Co(2,2'-bipy)3]2+. Inductively coupled plasma (ICP) analysis and XPS spectrum of 1 prove the presence of VV. TG curves of 1 and 2 indicate two weight loss steps. [ABSTRACT FROM AUTHOR]

A 1-D organic-inorganic hybrid compound, {Cu(en)2}[V2Mo6O26{Cu(en)2}2] · 4H2O [en = ethylenediamine] (1), was hydrothermally synthesized and characterized by IR, UV spectroscopy, TG/DTA analyses, and single crystal X-ray diffraction. The X-ray crystallography analysis reveals an infinitely extended 1-D chain constructed from a molybdovanadate cluster [V2Mo6O26]6- as a building unit, two copper(II) complex fragments, {Cu(en)2}2+, as attached groups and a copper(II) fragment, {Cu(en)2}2+, as a bridging group. Each chain links to adjacent chains through weaker secondary Cu-O interactions forming an interesting 3-D supramolecular architecture. [ABSTRACT FROM AUTHOR]

A new transition-metal (TM) complex of the Lindqvist polyanion Na[Cu(1, 3-pda)2]3[HNb6O19] · 3H2O (1, 3-pda = 1, 3-diaminopropane) has been prepared using pre-prepared TBA4[H4Nb6O19] · 7H2O as a precursor and characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, and thermogravimetric analysis. Crystal data for the compound: rhombohedral, space group R-3c, a = 14.927(4) Å, b = 14.927(4) Å, c = 36.940(18) Å, γ = 120°, V = 7128(4) Å3, Z = 6. The structural unit of the title compound consists of a polyanion [HNb6O19]7-, a Na+, three [Cu(1, 3-pda)2]2+, and three crystal water molecules. The occupancy of all Cu atoms and water molecules is 0.5. X-ray diffraction indicated that the cations and the polyanion were linked through electrostatic interactions and intermolecular forces. [ABSTRACT FROM AUTHOR]

A 1-D infinite chain organic-inorganic hybrid compound, [CuI(en)2(H2O)]2{GeW12O40[CuII(en)2]}·2.5H2O, was synthesized hydrothermally and characterized by IR, UV spectroscopy, TG analyses, and single-crystal X-ray diffraction. Structural analysis indicates that neighboring [GeW12O40]4- polyanions are interconnected by [Cu(3)(en)2]2+ subunits via W-Ot-Cu(3) bridges, generating a 1D infinite chain structure. Furthermore, the compound shows photoluminescence in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

A new polyoxometalate based on saturated Wells-Dawson polyanions and calcium cations, H2[Ca2(P2W18O62)(H2O)5] · 7.5H2O (1), has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction and IR. Compound 1 is a new example of 3D framework based on Wells-Dawson anions that act as chelate ligands to coordinate with calcium cations. Cyclic voltammetry reveals that the pH of the supporting electrolytic solution has a marked effect on the electrochemical behavior. [ABSTRACT FROM AUTHOR]

Two new polyoxometalate compounds based on the lacunary Keggin anion [α-GeW11O39]8- and the rare earth cation PrIII, [(CH3)4N]2.25H1.25[Pr1.5(GeW11O39)(H2O)5.75] · 1.25H2O (1) and [Pr0.5(H2O)2.25]H0.5[Pr2(GeW11O39)(DMSO)2(H2O)8] · 5.75H2O (2), have been synthesized and characterized by elemental analysis, inductively coupled plasma (ICP) analysis, IR and UV spectroscopy, and single-crystal X-ray diffraction. The solid-state structure of 1 consists of one-dimensional zig-zag chains built of [α-GeW11O39]8- anions connected by Pr3+. In 2, DMSO (DMSO = dimethyl sulfoxide) leads to a double-parallel chainlike structure constructed by two linear wires {[Pr(GeW11O39)(DMSO)(H2O)2]5-}n linked by Pr3+ coordination cations. [ABSTRACT FROM AUTHOR]

An organic-inorganic hybrid polyoxometalate [Ni(phen)(H2O)3]2[Ni(H2O)5][H2W12O40] · 6H2O (phen = 1,10-phenanthroline) has been isolated and characterized by IR, UV, electrochemistry and single-crystal X-ray diffraction. X-ray crystallographic study indicates that the title compound is monoclinic, space group C2/c, with lattice constants a = 21.7672(17), b = 16.1189(12), c = 20.7949(16) Å, β = 107.8440(10)°, V = 6945.2(9) Å3, Dc = 3.528 Mg m-3, F(000) = 6600, Z = 4, R1 = 0.0372, wR2 = 0.0845. The molecular fragment of the title compound consists of two supporting [Ni(phen)(H2O)3]2+ coordination cations, one supporting [Ni(H2O)5]2+ unit, one metatungstate polyoxoanion [H2W12O40]6- and six H2O molecules of crystallization. [ABSTRACT FROM AUTHOR]

A 1D chain organic–inorganic rare earth coordination polymer Gd 0.5 H 0.5 {[Gd(H 2 O) 6 ] [Gd(H 2 O) 2 (DMSO)][α-SiW 11 O 39 ]}·7H 2 O has been synthesized by reaction of α-K 8 SiW 11 O 39 ·13H 2 O, HClO 4 , Gd 2 O 3 with dimethyl sulfoxide (DMSO) and characterized by elemental analysis, IR, UV, ESR spectra and X-ray diffraction. The title compound crystallizes in a monoclinic lattice, P 2 1 /c space group, with a   =  23.544(5), b   =  11.527(2), c   =  23.297(5)  Å, β  =  109.05(3)°, V   =  35976(2)  Å 3 , Z   =  4, R 1   =  0.0838, wR 2   =  0.1300. The neighboring polyanion units {[Gd(H 2 O) 6 ][Gd(H 2 O) 2 (DMSO)][α-SiW 11 O 39 ]} 2- are bridged together forming a 1D chain structure by means of [Gd(H 2 O) 2 (DMSO)] 3+ ions. The ESR spectra of the title compound at room temperature are composed of eight lines, indicating the strong effect of the crystal field generated by the nearest surrounding ligands of the Gd III cation. [ABSTRACT FROM AUTHOR]

A 1D zigzag chain compound, [{Nd(NMP) 6 }(PMo 12 O 40 )] n , has been synthesized by reaction of α-H 3 PMo 12 O 40   ·   n H 2 O, Nd 2 O 3 and NMP (NMP  =   N -methyl-2-pyrrolidone) in acetonitrile–water mixture, and characterized by elemental analysis, IR and UV spectra, and X-ray single crystal structural analysis. The crystal structure indicates that the title compound forms a one-dimensional zigzag chain built from alternating polyanions and cationic units through Mo–O t –Nd–O t –Mo links. In the compound, Nd 3+ are eight-coordinate with a bicapped trigonal prism geometry of oxygen atoms, from six NMP molecules and two adjacent polyanions, and two terminal oxygen atoms of the polyanions occupying the caps. The powder ESR spectrum at 110  K of the title compound after being exposed to sunshine shows the signal of Mo 5+ , g   =  1.96. The CV shows that the title compound undergoes five two-electron reversible reductions and that [PMo 12 O 40 ] 3- are active centers for electrochemical redox in solutions; cations have a small effect on electrochemical redox. [ABSTRACT FROM AUTHOR]

One of the first examples of a transition metal complex coordinated to a Keggin-type anion [AlW 12 O 40 ] 5- : [Cu(2,2′-bipy) 2 ]{W V O 40 [Cu(2,2′-bipy) 2 ] 2 }·2H 2 O, was prepared by the hydrothermal method. Crystal data: monoclinic, space group P 2 1 / n , a   =  18.83(3), b   =  20.40(4), c   =  21.76(4)  Å, β  =  96.67(3)  °, V   =  8304(2)  Å 3 , Z   =  4, D c   =  3.229  Mg  m -3 , F (000)  =  7280, T   =  293(2)  K, μ(Mo-Kα)  =  17.402  mm -1 , R 1   =  0.0459, wR 2   =  0.0902, GOF  =  1.082. The title compound is discrete, with a Keggin unit [W V O 40 ] 6- linked to two transition metal coordination cations [Cu(2,2′-bipy) 2 ] 2+ via two surface bridging O atoms of the Keggin unit [W V O 40 ] 6- , respectively. In addition, there are discrete Cu(3) coordination cations [Cu(2,2′-bipy) 2 ] 2+ . [ABSTRACT FROM AUTHOR]

A novel organic–inorganic polymer of {H[Ba(DMF) 6 (PMo 12 O 40 )]·(dma)} n (dma  =  dimethylamine, DMF  =  N,N-dimethylformamide) has been synthesized and characterized. Single-crystal X-ray structural analysis indicates that the title compound crystallizes in a monoclinic lattice, C 2/c with a   =  22.336(5), b  =   12.798(3), c  =   21.498(4)  Å, β   =   99.77(3)°, Z  =   4, V  =   6065(2)  Å 3 , D c   =   2.673  Mg  m -3 , F (000)  =  4620, R 1   =  0.0600, wR 2   =  0.1125. Crystal structural analysis reveals that Ba 2+ ion lies in a distorted square antiprismatic environment with eight oxygen atoms, six from DMF molecules and two from adjacent polyanions. [Ba(DMF) 6 ] 2+ ions coordinated to [PMo 12 O 40 ] 3- building blocks form a 1D corrugated chain. The results of the single crystal X-ray diffraction and IR spectra show the metal cations are coordinated to Keggin clusters. The ESR spectra show that the title compound is strongly photosensitive towards sunlight. Cyclic voltammetry shows that the title compound undergoes five two-electron reversible reductions and the [PMo 12 O 40 ] 3- anions are the active centers for electrochemical redox reactions in solution. [ABSTRACT FROM AUTHOR]

A new two-dimensional compound C 12 H 14 O 16 Zn 3 (1), containing seven-coordinate zinc atoms was prepared by the hydrothermal technique. The compound obtained was characterized by TG-DTA, single crystal X-ray diffraction, elemental analysis and FT-IR analysis. Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes with monoclinic symmetry in the space group P 2 1 / c , a   =  6.1552(13)  Å, b   =  14.546(3)  Å, c   =  9.581  Å, β  =  102.66(2)°, V   =  836.9(4)  Å 3 , Z   =  2, R 1  =  0.0311, wR 2  =  0.0830. [ABSTRACT FROM AUTHOR]

A new organic-inorganic composite (4,4′-H 2 bipy) 2 (4,4′-Hbipy) 2 (ZnW 12 O 40 )·6H 2 O has been prepared by hydrothermal reaction and characterized by elemental analysis, IR and UV spectra, thermal analysis and single-crystal X-ray structural analysis. It belongs to the monoclinic system, space group P 2 1 / c , with a = 18.637(4), b = 14.003(3), c = 26.470(5) Å, β = 104.78(3)°, V = 6680(2) Å 3 , Z = 4. Structural analysis indicates that the title complex consists of a Keggin anion [ZnW 12 O 40 ] 6- , 4,4′-bipyridine and water of crystallization, constructing a supramolecular system through hydrogen bonding interactions. Thermal analysis shows that the heteropolyanion [ZnW 12 O 40 ] 6- starts to decompose at 587.0°C. [ABSTRACT FROM AUTHOR]

Two novel metatungstate compounds [Hdmpy] 4 H 2 [H 2 W 12 O 40 ]·4H 2 O (dmpy = 2,6-dimethyl pyridine) ( 1 ) and [Hpy] 4 H 2 [H 2 W 12 O 40 ] (py = pyridine) ( 2 ) have been synthesized by rational reaction, rather than hydrothermal or electrosynthetic reaction, of sodium tungstate dihydrate with 2,6-dimethyl pyridine and pyridine, respectively and characterized by IR and electronic spectroscopies, thermal behavior and electrochemistry. X-ray single-crystal structural analyses indicate that both structures consist of close-packed arrangements of the almost spherical Keggin-type anion [H 2 W 12 O 40 ] 6- with protonated 2,6-dimethyl pyridine or pyridine molecules filling the gap of the polyanions and interacting with the metatungstate anions in the mode of W-O···H-N or W-O···H-C, giving a two-dimensional network structure. The TG-DTA curves of 1 show that weight loss is divided into two stages, and reveal that the framework of the polyanion in 1 begins to decompose at 613°C. Electrochemical study shows that Compound 1 exhibits two chemically quasi-reversible one-electron reduction processes in aqueous solution (0.5 M NaCl + HCl) in the pH range 4-7. [ABSTRACT FROM AUTHOR]

The title compound, [Cu(2,2′-bipy) 3 ] 2 H 2 [H 2 W 12 O 40 ]·4.5H 2 O, was synthesized by hydrothermal reaction and characterized by IR and single-crystal X-ray structural analysis. It belongs to the triclinic, space group P with a = 13.929(3) Å, b = 17.493(4) Å, c = 19.210(4) Å, α = 86.39(3)°, β = 68.77(3)°, γ = 74.21(3)°, V = 4195.2(15) Å 3 , Z = 2, D c = 3.158 g cm -3 , μ = 16.970 mm -1 , F (000) = 3602. This is the first hybrid material based on a metatungstate ion and transition metal coordination cations in which each copper atom is coordinated by six N atoms from three 2,2′-bipyridine molecules forming a distorted octahedron. [ABSTRACT FROM AUTHOR]

The synthesis, X-ray crystal structure, IR, UV and ESR spectra, and thermal properties of the new complex formulated [Dy(NMP)4(H2O)3]HSiMo12O40] ⋅ 2NMP (NMP = N-methyl-2-pyrrolidone), are reported. The crystal structure indicates that the coordinated ion combines with [SiMo12O40]4- by an electrostatic force. There are several kinds of hydrogen bonding in the complex and the crystal structure shows that the water molecules in the coordination sphere play a dual role: they coordinate to the rare earth ions on one hand and form strong hydrogen bonds on the other. The complex is strongly photosensitive under irradiation with sunlight, resulting in charge transfer by oxidation of the N-methyl-2-pyrrolidone and reduction of the polyoxometalate. The low-temperature ESR spectra indicate that thermal electron delocalization occurs among the Mo atoms in the complex. [ABSTRACT FROM AUTHOR]

A new composite complex of [La(NMP) 4 (H 2 O) 4 ][HSiMo 12 O 40 ]·2NMP·H 2 O (NMP = N -methyl-2- pyrrolidone) was synthesized and characterized by IR, UV, ESR, TG-DTA and single crystal structural analysis. The water and organic ligands (NMP) coordinate directly with La(III) to form a dodecahedral complex and the SiMo 12 anion is the counter ion. IR and X-ray analysis show that there is strong interaction between the polyoxometalate and organic donors. The complex is strongly photosensitive under irradiation with sunlight, resulting in a charge-transfer complex by oxidation of the N -methyl-2-pyrrolidone and reduction of the polyoxometalate. Low temperature ESR spectra indicate thermal electron delocalization among the Mo atoms in the title compound. [ABSTRACT FROM AUTHOR]

The title compound, K 6.5 H 4.5 [CeK 2 (SiW 11 O 39 ) 2 ]·26H 2 O was prepared and its structure characterized by IR and single crystal X-ray structural analysis. It belongs to triclinic, space group P 1 with a = 12.719(3) Å, b = 16.658(4) Å, c = 23.075(6) Å, α = 94.41(2)°, β = 98.90(2)°, γ = 92.40(2)°; V = 4809(2) Å -3 , Z = 2, Dc = 4.344 g cm -3 , μ = 27.170 mm -1 , F (000) = 5519. The results show that the cerium and two potassium atoms link the two anionic units SiW 11 through O-Ce-O and O-K-O bridges and construct the double 1 : 11 series heteropolytungstate. Furthermore, cerium is coordinated to eight oxygen atoms (four O c and four O b ) from two tetradentate SiW 11 ligands forming a square anti-prism. The coordination numbers for K1 and K2 are 8 and 7, respectively. [ABSTRACT FROM AUTHOR]