Construction of two Ru^(Ⅲ)cations and six lacunary Keggin fragments resulted in a novel Ru_(2)W_(12)-cluster{(RuO_(6))_(2)(WO_(3))_(12)(H_(2)O)_(12)}bridged polyoxometalate,NaH_(11)[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6...Construction of two Ru^(Ⅲ)cations and six lacunary Keggin fragments resulted in a novel Ru_(2)W_(12)-cluster{(RuO_(6))_(2)(WO_(3))_(12)(H_(2)O)_(12)}bridged polyoxometalate,NaH_(11)[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]_(2)53H_(2)O(NaH_(11)·1·53H_(2)O),which represent the largest cluster in all the Ru-containing polyoxometalates.The most interesting characteristic is that the symmetry-related Ru_(2)W_(12)-cluster-based hexamers contain two windmill-shaped[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]trimers or the Ru_(2)W_(12) cluster was tightly wrapped by six segments of B-β-AsW_(9)O_(33).The other remarkable feature is that there have one intriguing cubane structure:which is composed of the Ru(1,2)and W(1,28,50,51,52,53)atoms.The oxygenation reactions of anilines to azoxybenzenes was evaluated when NaH_(11)·1·53H_(2)O served as effective catalyst by probing various reaction.The inherent redox property of oxygen-rich polyoxometalate surfaces and high photocatalytic activity of the Ru-containing metal cluster imbedded in NaH_(11)·1·53H_(2)O provide sufficient driving force for the photocatalytic transformation from anilines to azoxybenzenes.The oxidation of anilines can be realized with higher selectivity to afford various azoxybenzene compounds.The durability test shows that Ru-doping catalyst displays excellent chemical stability during the photocatalytic process.展开更多
A photoactive polyoxometalate-based metal-organic framework (POMOF),NiW-DPNDI,was synthesized by combination of Ni(Ⅱ) ions,[ZnW_(12)O_(40)]^(6–)anions,and N,N’-bis(4-pyridylmethyl)naphthalene diimide(DPNDI) molecul...A photoactive polyoxometalate-based metal-organic framework (POMOF),NiW-DPNDI,was synthesized by combination of Ni(Ⅱ) ions,[ZnW_(12)O_(40)]^(6–)anions,and N,N’-bis(4-pyridylmethyl)naphthalene diimide(DPNDI) molecules into one single framework.Ni W-DPNDI displays a three-dimensional structure by the strong anion···π interactions between the trapped[ZnW_(12)O_(40)]^(6–)anions and the electron-deficient naphthalenic ring centroids and theπ-πstacking interactions between DPNDI moieties.Ni W-DPNDI displayed a highly efficient hole-electron separation and ordered electron transfer under irradiation,thus ensuing its excellent photocatalysis in oxidation of styrene to produce benzaldehyde.In addition,it gave a high efficiency for styrene oxide under thermocatalytic conditions.Because the carbonic anhydrase (CA)-mimicking Ni sites and the negative electron-enriched[ZnW_(12)O_(40)]^(6–)anions are well aligned in the pores,it can promote the cycloaddition of CO_(2) with epoxides under mild conditions.展开更多
The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The mo...The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The monomer,K_(11)Li[P_(2)W_(12)(TaO_(2))_(6)O_(56)]·19H_(2)O(1),is composed of{P_(2)W_(12)}and 6{Ta(O_(2))}building blocks,similar to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-).Monomer 1 polymerized to form two cis-trans dimers,K1_(3)Li_(6)H-cis-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·61H_(2)O(2)and KNa_(3)Li_(4)H_(12)-trans-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·37H_(2)O(3).Compounds 1-3 can serve as a structural motif to manufacture additional fascinating molecular clusters,promoting the advancement of POM chemistry.In contrast to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-),compound 1 exhibits exceptional stability,evidenced by ESI-MS,IR,and NMR spectroscopy.In addition,2 and 3 exhibit high proton conductivity and superior water adsorption properties.展开更多
By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68...By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68H_(2)O(1)has been successfully obtained via one-pot method and systematically characterized by IR,XPS,solid UV spectra,PXRD pattern,and TGA analysis.The analysis of X-ray crystallography exhibits that compound 1 crystallizes in the triclinic space group P-1 and presents a novel square-shaped Zr-substituted tetrameric polyoxometalate.The catalytic oxidation of sulfides by 1 are carried out,which demonstrate that 1 exhibits a good performance for the catalytic oxidation of sulfides to sulfones with high conversion(100%)and high selectivity(100%).展开更多
The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of...The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of Dy_(2)(L_1)_(2)(L_(2))_(2)(CH_(3)OH)_(2)·CH_(2)Cl_(2)·CH_(3)OH(1) and Dy_(2)(L_1)_(2)(L_(3))_(2)(CH_(3)OH)_(2)·CH_(3)CN(2),where L_1,L_(2) and L_(3) represent the deprotonated form of 4-tert-butyl-2-(7-methoxybenzo[d]oxazol-2-yl)phenol,(E)-1-(((3,5-di-tert-butyI-2-hydroxyphenyI)imino)methyl)naphthalen-2-ol and(E)-2,4-di-tertbutyl-6-((2-hydroxybenzylidene)amino)phenol.The tiny difference of the core structure of 1 and 2 is derived from the steric hindrance of Schiff base ligands L_(2) and L_(3).Dynamic magnetic measurements reveal that 1 and 2 show frequency-dependent out-of-phase alternating-current susceptibility signal peaks at different temperatures under zero dc field,diagnostic of single-molecule magnet behavior.The experimental derived energy barrier to magnetization reversal for 1 and 2 is 108(1),47(2) and 33(3) K.Ab initio CASSCF calculations performed on 1 and 2 suggest that the origin of the difference in magnetic properties originates from the variation in the single-ion anisotropy that arises due to minor structural variation.Further,the equation to calculate the effective energy barrier for Dy_(2) proposed earlier is found to yield an excellent agreement with the experimental results.Solid state fluorescence measurements performed on 1 and 2 demonstrate that both exhibit two ligands centered components of fluorescent emissive,in addition,with different emitting colors and chromaticity coordinates.The discrepancy of fluorescence and single molecule magnet behavior showed by 1 and 2 can be attributed to the steric hindrance effect of Schiff base ligands.展开更多
Eu3+ions doped Zn(OH)F and ZnO micro-structures with specific morphologies were synthesized by a simple hydrothermal method only through altering the addition amount of NH4F and hexamethylenetetramine(HMT).The phase s...Eu3+ions doped Zn(OH)F and ZnO micro-structures with specific morphologies were synthesized by a simple hydrothermal method only through altering the addition amount of NH4F and hexamethylenetetramine(HMT).The phase structure,morphology and luminescence properties of the as-prepared samples were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),photoluminescence(PL)spectra and lifetime.The results indicate that the obtained Zn(OH)F:Eu^3+samples possess net-like and dandelion-like morphologies,which have an identical orthorhombic phase structure.It is found that the addition amount of raw materials such as NH4F and HMT plays a critical role for the formation of Zn(OH)F:Eu^3+.If the addition amounts of NH4F or HMT are reduced by half,the hexagonal ZnO:Eu^3+sample with peanut-like morphology can be obtained.Under the excitation of UV light,both the as-prepared Zn(OH)F:Eu^3+and ZnO:Eu^3+samples exhibit the characteristic emission of the doped Eu^3+.展开更多
We present the synthesis,characterization and photoluminescence properties of uranium-containing selenotungstate,[(UO_(2))_(3)(SeO_(3))_(3)Na_(5)(H_(2)O)_(6)(SeW_(6)O_(21))(SeW_(9)O_(33))_(3)]^(21–),which was isolate...We present the synthesis,characterization and photoluminescence properties of uranium-containing selenotungstate,[(UO_(2))_(3)(SeO_(3))_(3)Na_(5)(H_(2)O)_(6)(SeW_(6)O_(21))(SeW_(9)O_(33))_(3)]^(21–),which was isolated by a one-pot reaction of uranium nitrate with sodium tungstate and sodium selenite in a pH 5.2 aqueous solution at 90°C.In this study,the effect of the introduction of lone-electron pair containing heteroatoms on the structure is demonstrated,a three-layered heterometallic{Se_(3)U_(3)Na_(5)}cluster is encapsulated by two different anionic building block units:three trivacant Keggin{B-α-Se W_(9)O_(33)}and one Anderson{SeW_(6)O_(21)}.To our knowledge,the{Se_(3)U_(3)Na_(5)}cluster has never been observed in the polyoxometalate chemistry.The solidstate photoluminescence properties and lifetime decay behaviours of the title compound(1)have been measured at room temperature,and the photoluminescence spectrum displays the characteristic emission bands of corresponding uranyl cations.In addition,the photoluminescence quantum yield of 1 is 72%,which is almost three times that of starting material UO_(2)(NO_(3))_(2)·6H_(2)O(27%).By using this strategy,we envision that an increasing number of assemblies with‘open’clusters may be designed and obtained,in which the exposed oxygen atoms show strong affinity towards metal ions,providing new opportunities to generate bigger clusters or to tune existing properties.展开更多
Developing and exploring organic-inorganic hybrid multi-lanthanide(Ln)implanted heteropolyoxometalates(HPOMs)has bloomed into an emerging research fieId.In this article,two neoteric Dgluconic acids(H_(6)GA)concatenati...Developing and exploring organic-inorganic hybrid multi-lanthanide(Ln)implanted heteropolyoxometalates(HPOMs)has bloomed into an emerging research fieId.In this article,two neoteric Dgluconic acids(H_(6)GA)concatenating multi-Ln^(Ⅲ) implanted heteropoly tungstates K_(14)H_(10)[Ln_(4)(H_(2)O)_(4)W_(6)(H_(2)-GA)_(4) O_(12)(B-α-TeW_(9)O_(33))_(4)]·60 H_(2)O(Ln=La^(3+)(1),Pr^(3+)(2))were obtained in acidic aqueous system.Attractively,in the polyanion structure of 1 and 2,six WⅥand four LnⅢcenters are connected by four flexible H_(2)GA^(4-) ligands via carboxyl and hydroxyl groups,resulting in the heterometallic[Ln_(4)(H_(2)O)_(4)W_(6)H_(2)GA)_(4)O_(12)]^(8+)cluster and then the heterometallic cluster is surrounded by four[B-α-TeW_(9)O_(33)]^(8-)segments.Electrochemical measurements for the 1@CFMCN/GCE sensor(CFMCN=carboxylfunctionalized multiwalled carbon nanotube;GCE=glass carbon electrode)demonstrate that 1@CFMCN/GCE shows benign recognition response to detecting noradrenaline(NDA).This research expands the structural diversity of Ln-implanted HPOMs and presents an electrochemical platform of recognizing NDA in the field of biosensors.展开更多
The one-pot assembly reaction of a trilacunary,lone-pair-containing[B-α-SbW9O33]9.precursor with Co2+ions in an aqueous medium led to the isolation of a novel{SbO3(H2O)3}bridging,dicobalt-substituted,sandwich-type tu...The one-pot assembly reaction of a trilacunary,lone-pair-containing[B-α-SbW9O33]9.precursor with Co2+ions in an aqueous medium led to the isolation of a novel{SbO3(H2O)3}bridging,dicobalt-substituted,sandwich-type tungstoantimonate{Co2Sb2(H2O)10[B-β-SbW9O33]2}^4–(1a).This compound was structurally characterized in the solid state by single-crystal X-ray diffraction,elemental analyses,thermogravimetric analysis,and IR spectroscopy.The most remarkable feature was that 1a comprises two trilacunary[B-β-SbW9O33]9^-fragments trapping a novel,centrally symmetric,rhomb-like{Co2Sb2}belt with 10 terminal water molecules.When combined with the photosensitizer[Ru(bpy)3]^2+and the sacrificial electron acceptor S2O82.,1a exhibited efficient catalytic activity for water oxidation with a remarkable turnover number(TON)of 193,initial turnover frequency(TOFinitial)of 5.3 s^-1,O2 yield of 30.8%,and quantum yield(ФQY)of 36.2%under light-driven conditions.展开更多
A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides...A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.展开更多
A couple of chiral mononuclear copper(II)-tyrosine complexes[Cu(L-Tyr)_(2)](1)and[Cu(D-Tyr)_(2)](2)[Tyr=tyrosine]have been successfully synthesized in the aqueous solution and further characterized by elemental analys...A couple of chiral mononuclear copper(II)-tyrosine complexes[Cu(L-Tyr)_(2)](1)and[Cu(D-Tyr)_(2)](2)[Tyr=tyrosine]have been successfully synthesized in the aqueous solution and further characterized by elemental analyses,IR spectra,single-crystal X-ray diffraction and circular dichroism(CD)spectroscopy.Structural analysis indicates that 1 and 2 exhibit the interesting 1-D chainlike arrangement architected from the[Cu(L-Tyr)_(2)]or[Cu(D-Tyr)_(2)]units connected by Cu-O linkages.From the view of supramolecular chemistry,neighboring[Cu(L-Tyr)_(2)]or[Cu(D-Tyr)_(2)]units are interlinked through weak hydrogen-bonding interactions constructing the 3-D supramolecular structure.Variable-temperature magnetic susceptibilities of 1 and 2 were investigated,indicating that 1 and 2 exhibit the dominant ferromagnetic behavior.Moreover,the field-dependent magnetization mea-surements suggest that 1 and 2 possess an S=1/2 ground state.展开更多
A convenient,expeditious,and high-efficiency protocol for the transformation of alcohols into esters using a Co-modified N-doped mesoporous carbon material（Co-N/m-C）as the catalyst is proposed.The catalyst was prepa...A convenient,expeditious,and high-efficiency protocol for the transformation of alcohols into esters using a Co-modified N-doped mesoporous carbon material（Co-N/m-C）as the catalyst is proposed.The catalyst was prepared through direct pyrolysis of a macromolecular precursor.The catalyst prepared using a pyrolysis temperature of 900°C（labeled Co-N/m-C-900） exhibited the best per-formance.The strong coordination between the ultra-dispersed cobalt species and the pyridine nitrogen as well as the large area of the mesoporous surface resulted in a high turnover frequencymethyl benzoate.This value is much higher than those of state-of-the-art transition-metal-based nanocatalysts reported in the literature.Moreover,the catalyst exhibited general applicability to various structurally diverse alcohols,including benzylic,allylic,and heterocyclic alcohols,achieving the target esters in high yields.In addition,a preliminary evaluation revealed that Co-N/m-C-900 can be used six times without significant activity loss.In general,the process was rapid,simple,and cost-effective.展开更多
Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters ...Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.展开更多
Two novel uranium-containing selenotungstates Na_(3)[H_(19)(UO_(2))_(2)(μ_(2)-O)(Se_(2)W_(14)O_(52))_(2)]·41 H_(2)O(U_(2))and(NH_(4))_(10)[H_(4)(SeO)_(2)(UO_(2))_(2)(H_(2)O)_(2)(H_(2)Se_(2)W_(14)O_(52))(Se_(2)W_...Two novel uranium-containing selenotungstates Na_(3)[H_(19)(UO_(2))_(2)(μ_(2)-O)(Se_(2)W_(14)O_(52))_(2)]·41 H_(2)O(U_(2))and(NH_(4))_(10)[H_(4)(SeO)_(2)(UO_(2))_(2)(H_(2)O)_(2)(H_(2)Se_(2)W_(14)O_(52))(Se_(2)W_(14)O_(52))]·66 H_(2)O(Se_(2)U_(2))based on the{Se_(2)W_(14)O_(52)}unit were successfully prepared and fully characterized.To our knowledge,the uranium is firstly introduced into the selenotungstates.Moreover,it is notable that U_(2)exhibits excellent Lewis acid-base catalytic activities in the condensation cyclization of sulfonyl hydrazides with diketones to synthesize polysubstituted pyrazoles.All the desired products were obtained in moderate to good yields(up to 99%).展开更多
Synthesis of uranyl polyoxometalate clusters attract more attention but remain great challenging.Herein,two uranyl polyoxometalate inorganic clusters of{Na_(6)(NH_(4))_(19)[(TeW_(9)O_(33))_(4)[TeO_(2)(OH)](UO_(2))4(H_...Synthesis of uranyl polyoxometalate clusters attract more attention but remain great challenging.Herein,two uranyl polyoxometalate inorganic clusters of{Na_(6)(NH_(4))_(19)[(TeW_(9)O_(33))_(4)[TeO_(2)(OH)](UO_(2))4(H_(2)O)_(2)]·50H_(2)O}n(1,Te-U_(4))and(NH_(4))18{Na@[(TeW_(9)O_(32)OH)(TeW_(9)O_(33))_(2)[TeO(OH)][W_(3)O_(12)(μ_(3)-OH)](UO_(2))_(6)(μ_(2)-OH)_(2)H_(2)O]}·75H_(2)O(2,Te-U6)were prepared using trilacunary[α-B-TeW_(9)O_(33)]8-as inorganic ligands.Structural analysis showed that compound 1 is a one-dimensional chain structure formed by tetrameric aggregates of[(α-B-TeW_(9)O_(33))_(4)(TeO_(2)(OH))(UO_(2))_(4)(H_(2)O)2]25-as nodes and Na+ions as linkers.The anionic tetrameric aggregates in 1 is made of two sandwich-type dimers of[(TeW_(9)O_(33))_(2)(UO_(2))_(2)H_(2)O]12-bridged by a[TeO_(2)(OH)]-unit.Compound 2 is a triangular trimeric architecture templated by Na+ion.The solid-state luminescence emission spectra of compounds 1 and 2 show the characteristic peaks of uranyl ions.Compound 1 with one-dimensional chain structure exhibited a higher photoluminescence quantum yields(PLQY)than that of 2,due to the more rigidity of 1 reducing the nonradiative transitions.展开更多
A series of DL-serine covalently modified multinuclear lanthanide implanted arsenotungstates K_(2)[{Ln(H_(2)O)_(7)}_(2){As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]·65H_(...A series of DL-serine covalently modified multinuclear lanthanide implanted arsenotungstates K_(2)[{Ln(H_(2)O)_(7)}_(2){As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]·65H_(2)O(DL-Ser=DL-serine,Ln=La(1),Ce(2),Pr(3))are obtained.Crystal structure analysis shows that these compounds are isomorphic and contain the basic[{As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]^(8–)polyoxoanion constituted by two{As_(2)W_(19)O_(59)(OH)_(8)(H_(2)O)}^(6–)subunits,a[W_(6)O_(2)_(3)(OH)_(2)(DL-Ser)_(2)]_(14)–fragment,and two embedded[Ln_(2)(H_(2)O)_(5)(DL-Ser)]^(5+)groups,which further build into one dimensional linear chainlike structure via two peripheral Ln^(3+)ions.Most remarkably,these compounds exhibit rapid photochromic behaviors,which changed color quickly from white(1),yellow(2),green(3)to blue(1),brown(2)and glaucous(3)in ten minutes under UV irradiation,and that the colors gradually recovered in the dark for approximately 22 h.展开更多
A new organic-inorganic hybrid sandwich-type polyoxotungstate [Cu（dien）-（H2O）2]2[{Cu（dien）（H2O）}3{Cu（4.5）W（0.5）（B-α-Sb W9O（33））2}]（OH）4·7H2O（1, dien = diethylenetriamine） has been hydrotherma...A new organic-inorganic hybrid sandwich-type polyoxotungstate [Cu（dien）-（H2O）2]2[{Cu（dien）（H2O）}3{Cu（4.5）W（0.5）（B-α-Sb W9O（33））2}]（OH）4·7H2O（1, dien = diethylenetriamine） has been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, TG analysis, and single-crystal X-ray diffraction analysis. Crystal data for 1： monoclinic, C2/c, a = 31.527（3）, b = 13.9309（13）, c = 24.297（2） A, β = 1108.269（2）°, V = 10133.2（17） A3, Dc = 4.024 g/cm3 and Z = 4. X-ray crystallographic study shows that the molecular structure of 1contains an infrequent penta-nuclearity {Cu4.5W0.5} cluster sandwiched polyanion [{Cu4.5W0.5（B-α-Sb W9O33）2}]6-, on which three [Cu（dien）（H2O）]2＋ complexes decorated as pendants. Interestingly, two [Cu（dien）（H2O）]2＋ pendants linked the two neighboring sandwich-type polyanions via double Cu-μ2-O-W bridges, resulting in a 1-D chain. The magnetic measurements show compound 1exhibits obvious antiferromagnetic interactions.展开更多
A novel organic-inorganic hybrid arsenatomolybdate based on infrequent[AsMoO(OH)]unit,[Cu ~I(phen)][AsMoO(OH)]·3HO(1,phen=1,10-phenanthroline),has been hydrothermally synthe-sized.This structure was determined by...A novel organic-inorganic hybrid arsenatomolybdate based on infrequent[AsMoO(OH)]unit,[Cu ~I(phen)][AsMoO(OH)]·3HO(1,phen=1,10-phenanthroline),has been hydrothermally synthe-sized.This structure was determined by single-crystal X-ray diffraction analysis,and further characterized by elemental analysis,and IR and UV spectra.To the best of our knowledge,it is the first report of a novel arsenatomolybdate subunit[AsMoO(OH)].Photoluminescence of 1 is ascribed to???*emission of the aromatic rings derived from the phen ligand.展开更多
A new organic-inorganic hybrid phosphotungstate-based Cu^Ⅱ-Er^Ⅲ heterometallic derivative[Cu（dap）2（H2O）][Cu（dap）2]4.5[Er（α-PW11O39）2]·4H2O（1,dap = 1,2-diaminopropane） has been hydrothermally prepared...A new organic-inorganic hybrid phosphotungstate-based Cu^Ⅱ-Er^Ⅲ heterometallic derivative[Cu（dap）2（H2O）][Cu（dap）2]4.5[Er（α-PW11O39）2]·4H2O（1,dap = 1,2-diaminopropane） has been hydrothermally prepared and characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.1 belongs to the triclinic space group P1 with a = 13.453（3）,b =20.137（4）,c = 24.565（4） A,α = 103.468（4）,β = 103.829（4）,γ = 98.296（4）°,V= 6148.0（19） A°3,Z =2,μ = 22.212 mm^-1,GOOF = 1.030,R = 0.0744 and wR = 0.1700.Structural analysis indicates that1 exhibits a special two-dimensional double-layer structure constructed from l：2-type[Er（α-PW11O39）2]^11- moieties and[Cu（dap）2]^2＋ linkers.From the topological viewpoint,1 displays a scare two-dimensional five-connected topology in which the[Er（α-PW11O39）2]^11- moieties function as the five-connected nodes.Furthermore,its thermogravimetric behavior has been studied.展开更多
Three isomorphic polytungstates,CsgK_(18)H_(10){[Sm_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))3]_(2)(N(CH_(2)PO_(3))_(2))}:46.5H_(2)O(1),CS_(10)K_(9)H_(18){[Eu_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))_(3)]_(2)(N(CH_(2...Three isomorphic polytungstates,CsgK_(18)H_(10){[Sm_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))3]_(2)(N(CH_(2)PO_(3))_(2))}:46.5H_(2)O(1),CS_(10)K_(9)H_(18){[Eu_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}.41.5H_(2)O(2),Cs_(10)K_(9)H_(18){[Gd_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)O_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}:46H_(2)O(_(3)),have been successfully synthesized and characterized by routine methods,and demonstrated excellent catalytic activities in Knoevenagel condensation reaction as heterogeneous catalysts.Notably,catalyst 1 achieved higher reaction activity than catalysts 2 and 3,where a satisfactory reaction yield(95%)and high TON value(6380)could be obtained at moderate reaction condition.In addition,in the scale-up experiment,with the help of catalyst 1,7.8g benzaldehyde and 5.7g ethyl cyanoacetate could transform into corresponding condensation product with a satisfactory yield(83%)and impressive TON value(13.883).展开更多
基金supported bythe National Natural Science Foundationof China(Nos.22171071,22071044,21771054,21571050)。
文摘Construction of two Ru^(Ⅲ)cations and six lacunary Keggin fragments resulted in a novel Ru_(2)W_(12)-cluster{(RuO_(6))_(2)(WO_(3))_(12)(H_(2)O)_(12)}bridged polyoxometalate,NaH_(11)[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]_(2)53H_(2)O(NaH_(11)·1·53H_(2)O),which represent the largest cluster in all the Ru-containing polyoxometalates.The most interesting characteristic is that the symmetry-related Ru_(2)W_(12)-cluster-based hexamers contain two windmill-shaped[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]trimers or the Ru_(2)W_(12) cluster was tightly wrapped by six segments of B-β-AsW_(9)O_(33).The other remarkable feature is that there have one intriguing cubane structure:which is composed of the Ru(1,2)and W(1,28,50,51,52,53)atoms.The oxygenation reactions of anilines to azoxybenzenes was evaluated when NaH_(11)·1·53H_(2)O served as effective catalyst by probing various reaction.The inherent redox property of oxygen-rich polyoxometalate surfaces and high photocatalytic activity of the Ru-containing metal cluster imbedded in NaH_(11)·1·53H_(2)O provide sufficient driving force for the photocatalytic transformation from anilines to azoxybenzenes.The oxidation of anilines can be realized with higher selectivity to afford various azoxybenzene compounds.The durability test shows that Ru-doping catalyst displays excellent chemical stability during the photocatalytic process.
基金supported by the Natural Science Foundation of Henan (Nos. 202300410043 and 222102230091)the Key Scientific Research Project of Henan Higher Education Institutions (No. 20ZX006)the National Natural Science Foundation of China (No. 21601048)。
文摘A photoactive polyoxometalate-based metal-organic framework (POMOF),NiW-DPNDI,was synthesized by combination of Ni(Ⅱ) ions,[ZnW_(12)O_(40)]^(6–)anions,and N,N’-bis(4-pyridylmethyl)naphthalene diimide(DPNDI) molecules into one single framework.Ni W-DPNDI displays a three-dimensional structure by the strong anion···π interactions between the trapped[ZnW_(12)O_(40)]^(6–)anions and the electron-deficient naphthalenic ring centroids and theπ-πstacking interactions between DPNDI moieties.Ni W-DPNDI displayed a highly efficient hole-electron separation and ordered electron transfer under irradiation,thus ensuing its excellent photocatalysis in oxidation of styrene to produce benzaldehyde.In addition,it gave a high efficiency for styrene oxide under thermocatalytic conditions.Because the carbonic anhydrase (CA)-mimicking Ni sites and the negative electron-enriched[ZnW_(12)O_(40)]^(6–)anions are well aligned in the pores,it can promote the cycloaddition of CO_(2) with epoxides under mild conditions.
基金supported by the National Natural Science Foundation of China(Nos.22071044,21771054 and 22171071)。
文摘The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The monomer,K_(11)Li[P_(2)W_(12)(TaO_(2))_(6)O_(56)]·19H_(2)O(1),is composed of{P_(2)W_(12)}and 6{Ta(O_(2))}building blocks,similar to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-).Monomer 1 polymerized to form two cis-trans dimers,K1_(3)Li_(6)H-cis-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·61H_(2)O(2)and KNa_(3)Li_(4)H_(12)-trans-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·37H_(2)O(3).Compounds 1-3 can serve as a structural motif to manufacture additional fascinating molecular clusters,promoting the advancement of POM chemistry.In contrast to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-),compound 1 exhibits exceptional stability,evidenced by ESI-MS,IR,and NMR spectroscopy.In addition,2 and 3 exhibit high proton conductivity and superior water adsorption properties.
基金financially supported by the National Natural Science Foundation of China(No.22071043).
文摘By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68H_(2)O(1)has been successfully obtained via one-pot method and systematically characterized by IR,XPS,solid UV spectra,PXRD pattern,and TGA analysis.The analysis of X-ray crystallography exhibits that compound 1 crystallizes in the triclinic space group P-1 and presents a novel square-shaped Zr-substituted tetrameric polyoxometalate.The catalytic oxidation of sulfides by 1 are carried out,which demonstrate that 1 exhibits a good performance for the catalytic oxidation of sulfides to sulfones with high conversion(100%)and high selectivity(100%).
基金Project supported by National Natural Science Foundation of China (21601143)Natural Science Foundation of Shaanxi Province (2021JM309)+2 种基金Open Funds of the State Key Laboratory of Rare Earth Resource of Changchun Institute of Applied Chemistry (RERU2021012)Science and Technology Innovation Team Program of Shaanxi Province (2022TD-32) and DST/SERB (CRG/2018/000430,DST/SJF/CSA03/2018-10SB/SJF/2019-20/12)。
文摘The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of Dy_(2)(L_1)_(2)(L_(2))_(2)(CH_(3)OH)_(2)·CH_(2)Cl_(2)·CH_(3)OH(1) and Dy_(2)(L_1)_(2)(L_(3))_(2)(CH_(3)OH)_(2)·CH_(3)CN(2),where L_1,L_(2) and L_(3) represent the deprotonated form of 4-tert-butyl-2-(7-methoxybenzo[d]oxazol-2-yl)phenol,(E)-1-(((3,5-di-tert-butyI-2-hydroxyphenyI)imino)methyl)naphthalen-2-ol and(E)-2,4-di-tertbutyl-6-((2-hydroxybenzylidene)amino)phenol.The tiny difference of the core structure of 1 and 2 is derived from the steric hindrance of Schiff base ligands L_(2) and L_(3).Dynamic magnetic measurements reveal that 1 and 2 show frequency-dependent out-of-phase alternating-current susceptibility signal peaks at different temperatures under zero dc field,diagnostic of single-molecule magnet behavior.The experimental derived energy barrier to magnetization reversal for 1 and 2 is 108(1),47(2) and 33(3) K.Ab initio CASSCF calculations performed on 1 and 2 suggest that the origin of the difference in magnetic properties originates from the variation in the single-ion anisotropy that arises due to minor structural variation.Further,the equation to calculate the effective energy barrier for Dy_(2) proposed earlier is found to yield an excellent agreement with the experimental results.Solid state fluorescence measurements performed on 1 and 2 demonstrate that both exhibit two ligands centered components of fluorescent emissive,in addition,with different emitting colors and chromaticity coordinates.The discrepancy of fluorescence and single molecule magnet behavior showed by 1 and 2 can be attributed to the steric hindrance effect of Schiff base ligands.
基金Project supported by the National Natural Science Foundation of China(51572303)
文摘Eu3+ions doped Zn(OH)F and ZnO micro-structures with specific morphologies were synthesized by a simple hydrothermal method only through altering the addition amount of NH4F and hexamethylenetetramine(HMT).The phase structure,morphology and luminescence properties of the as-prepared samples were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),photoluminescence(PL)spectra and lifetime.The results indicate that the obtained Zn(OH)F:Eu^3+samples possess net-like and dandelion-like morphologies,which have an identical orthorhombic phase structure.It is found that the addition amount of raw materials such as NH4F and HMT plays a critical role for the formation of Zn(OH)F:Eu^3+.If the addition amounts of NH4F or HMT are reduced by half,the hexagonal ZnO:Eu^3+sample with peanut-like morphology can be obtained.Under the excitation of UV light,both the as-prepared Zn(OH)F:Eu^3+and ZnO:Eu^3+samples exhibit the characteristic emission of the doped Eu^3+.
基金supported by the National Natural Science Foundation of China(Nos.22071045 and 22001034)Excellent Youth Science Fund Project of Henan Province(No.202300410042)+1 种基金the Open Fund of the Jiangxi Province Key Laboratory of Synthetic Chemistry(No.JXSC202008)the start-up fund for Distinguished Professor of Henan University。
文摘We present the synthesis,characterization and photoluminescence properties of uranium-containing selenotungstate,[(UO_(2))_(3)(SeO_(3))_(3)Na_(5)(H_(2)O)_(6)(SeW_(6)O_(21))(SeW_(9)O_(33))_(3)]^(21–),which was isolated by a one-pot reaction of uranium nitrate with sodium tungstate and sodium selenite in a pH 5.2 aqueous solution at 90°C.In this study,the effect of the introduction of lone-electron pair containing heteroatoms on the structure is demonstrated,a three-layered heterometallic{Se_(3)U_(3)Na_(5)}cluster is encapsulated by two different anionic building block units:three trivacant Keggin{B-α-Se W_(9)O_(33)}and one Anderson{SeW_(6)O_(21)}.To our knowledge,the{Se_(3)U_(3)Na_(5)}cluster has never been observed in the polyoxometalate chemistry.The solidstate photoluminescence properties and lifetime decay behaviours of the title compound(1)have been measured at room temperature,and the photoluminescence spectrum displays the characteristic emission bands of corresponding uranyl cations.In addition,the photoluminescence quantum yield of 1 is 72%,which is almost three times that of starting material UO_(2)(NO_(3))_(2)·6H_(2)O(27%).By using this strategy,we envision that an increasing number of assemblies with‘open’clusters may be designed and obtained,in which the exposed oxygen atoms show strong affinity towards metal ions,providing new opportunities to generate bigger clusters or to tune existing properties.
基金Project supported by the National Natural Science Foundation of China(21871077,21671054,21771052,22071042,22001058,22171070)the Program for Innovation Teams in Science and Technology in Universities of Henan Province(20IRTSTHN004)。
文摘Developing and exploring organic-inorganic hybrid multi-lanthanide(Ln)implanted heteropolyoxometalates(HPOMs)has bloomed into an emerging research fieId.In this article,two neoteric Dgluconic acids(H_(6)GA)concatenating multi-Ln^(Ⅲ) implanted heteropoly tungstates K_(14)H_(10)[Ln_(4)(H_(2)O)_(4)W_(6)(H_(2)-GA)_(4) O_(12)(B-α-TeW_(9)O_(33))_(4)]·60 H_(2)O(Ln=La^(3+)(1),Pr^(3+)(2))were obtained in acidic aqueous system.Attractively,in the polyanion structure of 1 and 2,six WⅥand four LnⅢcenters are connected by four flexible H_(2)GA^(4-) ligands via carboxyl and hydroxyl groups,resulting in the heterometallic[Ln_(4)(H_(2)O)_(4)W_(6)H_(2)GA)_(4)O_(12)]^(8+)cluster and then the heterometallic cluster is surrounded by four[B-α-TeW_(9)O_(33)]^(8-)segments.Electrochemical measurements for the 1@CFMCN/GCE sensor(CFMCN=carboxylfunctionalized multiwalled carbon nanotube;GCE=glass carbon electrode)demonstrate that 1@CFMCN/GCE shows benign recognition response to detecting noradrenaline(NDA).This research expands the structural diversity of Ln-implanted HPOMs and presents an electrochemical platform of recognizing NDA in the field of biosensors.
基金financially supported by the National Natural Science Foundation of China(21773096)the Fundamental Research Funds for the Central Universities(lzujbky-2018-k08)the Natural Science Foundation of Gansu Province(17JR5RA186)~~
文摘The one-pot assembly reaction of a trilacunary,lone-pair-containing[B-α-SbW9O33]9.precursor with Co2+ions in an aqueous medium led to the isolation of a novel{SbO3(H2O)3}bridging,dicobalt-substituted,sandwich-type tungstoantimonate{Co2Sb2(H2O)10[B-β-SbW9O33]2}^4–(1a).This compound was structurally characterized in the solid state by single-crystal X-ray diffraction,elemental analyses,thermogravimetric analysis,and IR spectroscopy.The most remarkable feature was that 1a comprises two trilacunary[B-β-SbW9O33]9^-fragments trapping a novel,centrally symmetric,rhomb-like{Co2Sb2}belt with 10 terminal water molecules.When combined with the photosensitizer[Ru(bpy)3]^2+and the sacrificial electron acceptor S2O82.,1a exhibited efficient catalytic activity for water oxidation with a remarkable turnover number(TON)of 193,initial turnover frequency(TOFinitial)of 5.3 s^-1,O2 yield of 30.8%,and quantum yield(ФQY)of 36.2%under light-driven conditions.
基金financially supported by the National Natural Science Foundation of China (Nos. 22001034 and 21804019)the Open Fund of the Jiangxi Province Key Laboratory of Synthetic Chemistry (No. JXSC202008)the Research Found of East China University of Technology (Nos. DHBK2019264, DHBK2019265 and DHBK2019267)。
文摘A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.
基金Supported by the Natural Science Foundation of China(21671054)the Students Innovative Pilot Plan of Henan University(16NA005)
文摘A couple of chiral mononuclear copper(II)-tyrosine complexes[Cu(L-Tyr)_(2)](1)and[Cu(D-Tyr)_(2)](2)[Tyr=tyrosine]have been successfully synthesized in the aqueous solution and further characterized by elemental analyses,IR spectra,single-crystal X-ray diffraction and circular dichroism(CD)spectroscopy.Structural analysis indicates that 1 and 2 exhibit the interesting 1-D chainlike arrangement architected from the[Cu(L-Tyr)_(2)]or[Cu(D-Tyr)_(2)]units connected by Cu-O linkages.From the view of supramolecular chemistry,neighboring[Cu(L-Tyr)_(2)]or[Cu(D-Tyr)_(2)]units are interlinked through weak hydrogen-bonding interactions constructing the 3-D supramolecular structure.Variable-temperature magnetic susceptibilities of 1 and 2 were investigated,indicating that 1 and 2 exhibit the dominant ferromagnetic behavior.Moreover,the field-dependent magnetization mea-surements suggest that 1 and 2 possess an S=1/2 ground state.
基金supported by the National Natural Science Foundation of China (21773232, 21403219, 21773227)~~
文摘A convenient,expeditious,and high-efficiency protocol for the transformation of alcohols into esters using a Co-modified N-doped mesoporous carbon material（Co-N/m-C）as the catalyst is proposed.The catalyst was prepared through direct pyrolysis of a macromolecular precursor.The catalyst prepared using a pyrolysis temperature of 900°C（labeled Co-N/m-C-900） exhibited the best per-formance.The strong coordination between the ultra-dispersed cobalt species and the pyridine nitrogen as well as the large area of the mesoporous surface resulted in a high turnover frequencymethyl benzoate.This value is much higher than those of state-of-the-art transition-metal-based nanocatalysts reported in the literature.Moreover,the catalyst exhibited general applicability to various structurally diverse alcohols,including benzylic,allylic,and heterocyclic alcohols,achieving the target esters in high yields.In addition,a preliminary evaluation revealed that Co-N/m-C-900 can be used six times without significant activity loss.In general,the process was rapid,simple,and cost-effective.
基金supported by the National Natural Science Foundation of China(Nos.22071043 and 22203027)Shanxi Province Science Foundation(No.202303021211194)the program for the(Reserved)Discipline Leaders of Taiyuan Institute of Technology.
文摘Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.
基金supported by the National Natural Science Foundation of China(Nos.22071045,22001034)Excellent Youth Science Fund Project of Henan Province(No.202300410042)+1 种基金the Open Fund of the Jiangxi Province Key Laboratory of Synthetic Chemistry(No.JXSC202008)the start-up fund of Henan University。
文摘Two novel uranium-containing selenotungstates Na_(3)[H_(19)(UO_(2))_(2)(μ_(2)-O)(Se_(2)W_(14)O_(52))_(2)]·41 H_(2)O(U_(2))and(NH_(4))_(10)[H_(4)(SeO)_(2)(UO_(2))_(2)(H_(2)O)_(2)(H_(2)Se_(2)W_(14)O_(52))(Se_(2)W_(14)O_(52))]·66 H_(2)O(Se_(2)U_(2))based on the{Se_(2)W_(14)O_(52)}unit were successfully prepared and fully characterized.To our knowledge,the uranium is firstly introduced into the selenotungstates.Moreover,it is notable that U_(2)exhibits excellent Lewis acid-base catalytic activities in the condensation cyclization of sulfonyl hydrazides with diketones to synthesize polysubstituted pyrazoles.All the desired products were obtained in moderate to good yields(up to 99%).
基金the National Natural Science Foundation of China(Grant Nos.21901002,92161104,21871224,92161203,and 21721001)。
文摘Synthesis of uranyl polyoxometalate clusters attract more attention but remain great challenging.Herein,two uranyl polyoxometalate inorganic clusters of{Na_(6)(NH_(4))_(19)[(TeW_(9)O_(33))_(4)[TeO_(2)(OH)](UO_(2))4(H_(2)O)_(2)]·50H_(2)O}n(1,Te-U_(4))and(NH_(4))18{Na@[(TeW_(9)O_(32)OH)(TeW_(9)O_(33))_(2)[TeO(OH)][W_(3)O_(12)(μ_(3)-OH)](UO_(2))_(6)(μ_(2)-OH)_(2)H_(2)O]}·75H_(2)O(2,Te-U6)were prepared using trilacunary[α-B-TeW_(9)O_(33)]8-as inorganic ligands.Structural analysis showed that compound 1 is a one-dimensional chain structure formed by tetrameric aggregates of[(α-B-TeW_(9)O_(33))_(4)(TeO_(2)(OH))(UO_(2))_(4)(H_(2)O)2]25-as nodes and Na+ions as linkers.The anionic tetrameric aggregates in 1 is made of two sandwich-type dimers of[(TeW_(9)O_(33))_(2)(UO_(2))_(2)H_(2)O]12-bridged by a[TeO_(2)(OH)]-unit.Compound 2 is a triangular trimeric architecture templated by Na+ion.The solid-state luminescence emission spectra of compounds 1 and 2 show the characteristic peaks of uranyl ions.Compound 1 with one-dimensional chain structure exhibited a higher photoluminescence quantum yields(PLQY)than that of 2,due to the more rigidity of 1 reducing the nonradiative transitions.
基金supported by the National Natural Science Foundation of China(No.222071043)the Major Project of Science and Technology,Education Department of Henan Province(No.20A150010)the 2021 Students Innovative Pilot Plan of Henan University(No.202110475079)。
文摘A series of DL-serine covalently modified multinuclear lanthanide implanted arsenotungstates K_(2)[{Ln(H_(2)O)_(7)}_(2){As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]·65H_(2)O(DL-Ser=DL-serine,Ln=La(1),Ce(2),Pr(3))are obtained.Crystal structure analysis shows that these compounds are isomorphic and contain the basic[{As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]^(8–)polyoxoanion constituted by two{As_(2)W_(19)O_(59)(OH)_(8)(H_(2)O)}^(6–)subunits,a[W_(6)O_(2)_(3)(OH)_(2)(DL-Ser)_(2)]_(14)–fragment,and two embedded[Ln_(2)(H_(2)O)_(5)(DL-Ser)]^(5+)groups,which further build into one dimensional linear chainlike structure via two peripheral Ln^(3+)ions.Most remarkably,these compounds exhibit rapid photochromic behaviors,which changed color quickly from white(1),yellow(2),green(3)to blue(1),brown(2)and glaucous(3)in ten minutes under UV irradiation,and that the colors gradually recovered in the dark for approximately 22 h.
基金supported by the Foundation of Education Department of Henan Province(15A150037)
文摘A new organic-inorganic hybrid sandwich-type polyoxotungstate [Cu（dien）-（H2O）2]2[{Cu（dien）（H2O）}3{Cu（4.5）W（0.5）（B-α-Sb W9O（33））2}]（OH）4·7H2O（1, dien = diethylenetriamine） has been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, TG analysis, and single-crystal X-ray diffraction analysis. Crystal data for 1： monoclinic, C2/c, a = 31.527（3）, b = 13.9309（13）, c = 24.297（2） A, β = 1108.269（2）°, V = 10133.2（17） A3, Dc = 4.024 g/cm3 and Z = 4. X-ray crystallographic study shows that the molecular structure of 1contains an infrequent penta-nuclearity {Cu4.5W0.5} cluster sandwiched polyanion [{Cu4.5W0.5（B-α-Sb W9O33）2}]6-, on which three [Cu（dien）（H2O）]2＋ complexes decorated as pendants. Interestingly, two [Cu（dien）（H2O）]2＋ pendants linked the two neighboring sandwich-type polyanions via double Cu-μ2-O-W bridges, resulting in a 1-D chain. The magnetic measurements show compound 1exhibits obvious antiferromagnetic interactions.
基金supported by the Foundation of Education Department of Henan Province(15A150037)
文摘A novel organic-inorganic hybrid arsenatomolybdate based on infrequent[AsMoO(OH)]unit,[Cu ~I(phen)][AsMoO(OH)]·3HO(1,phen=1,10-phenanthroline),has been hydrothermally synthe-sized.This structure was determined by single-crystal X-ray diffraction analysis,and further characterized by elemental analysis,and IR and UV spectra.To the best of our knowledge,it is the first report of a novel arsenatomolybdate subunit[AsMoO(OH)].Photoluminescence of 1 is ascribed to???*emission of the aromatic rings derived from the phen ligand.
基金supported by the Natural Science Foundation of China(21301049,U1304208)the Natural Science Foundation of Henan Province(122300410106)
文摘A new organic-inorganic hybrid phosphotungstate-based Cu^Ⅱ-Er^Ⅲ heterometallic derivative[Cu（dap）2（H2O）][Cu（dap）2]4.5[Er（α-PW11O39）2]·4H2O（1,dap = 1,2-diaminopropane） has been hydrothermally prepared and characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.1 belongs to the triclinic space group P1 with a = 13.453（3）,b =20.137（4）,c = 24.565（4） A,α = 103.468（4）,β = 103.829（4）,γ = 98.296（4）°,V= 6148.0（19） A°3,Z =2,μ = 22.212 mm^-1,GOOF = 1.030,R = 0.0744 and wR = 0.1700.Structural analysis indicates that1 exhibits a special two-dimensional double-layer structure constructed from l：2-type[Er（α-PW11O39）2]^11- moieties and[Cu（dap）2]^2＋ linkers.From the topological viewpoint,1 displays a scare two-dimensional five-connected topology in which the[Er（α-PW11O39）2]^11- moieties function as the five-connected nodes.Furthermore,its thermogravimetric behavior has been studied.
基金support from the National Science Foundation of China(Nos.21620102002,91422302,21371048,91222102 and 21573056).
文摘Three isomorphic polytungstates,CsgK_(18)H_(10){[Sm_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))3]_(2)(N(CH_(2)PO_(3))_(2))}:46.5H_(2)O(1),CS_(10)K_(9)H_(18){[Eu_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}.41.5H_(2)O(2),Cs_(10)K_(9)H_(18){[Gd_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)O_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}:46H_(2)O(_(3)),have been successfully synthesized and characterized by routine methods,and demonstrated excellent catalytic activities in Knoevenagel condensation reaction as heterogeneous catalysts.Notably,catalyst 1 achieved higher reaction activity than catalysts 2 and 3,where a satisfactory reaction yield(95%)and high TON value(6380)could be obtained at moderate reaction condition.In addition,in the scale-up experiment,with the help of catalyst 1,7.8g benzaldehyde and 5.7g ethyl cyanoacetate could transform into corresponding condensation product with a satisfactory yield(83%)and impressive TON value(13.883).
