Dual Channel H2O2 Photosynthesis in Pure Water over S-Scheme Heterojunction Cs3PMo12/CC Boosted by Proton and Electron Reservoirs.

Dual channel photo-driven H2O2 production in pure water on small-scale on-site setups is a promising strategy to provide low-concentrated H2O2 whenever needed. This process suffers, however, strongly from the fast recombination of photo-generated charge carriers and the sluggish oxidation process. Here, insoluble Keggin-type cesium phosphomolybdate Cs3PMo12O40 (abbreviated to Cs3PMo12) is introduced to carbonized cellulose (CC) to construct S-scheme heterojunction Cs3PMo12/CC. Dual channel H2O2 photosynthesis from both H2O oxidation and O2 reduction in pure water has been thus achieved with the production rate of 20.1 mmol L-1 gcat. -1 h-1, apparent quantum yield (AQY) of 2.1% and solar-to-chemical conversion (SCC) efficiency of 0.050%. H2O2 accumulative concentration reaches 4.9 mmol L-1. This high photocatalytic activity is guaranteed by unique features of Cs3PMo12/CC, namely, S-scheme heterojunction, electron reservoir, and proton reservoir. The former two enhance the separation of photo-generated charge carriers, while the latter speeds up the torpid oxidation process. In situ experiments reveal that H2O2 is formed via successive single-electron transfer in both channels. In real practice, exposing the reaction system under natural sunlight outdoors successfully results in 0.24 mmol L-1 H2O2. This work provides a key practical strategy for designing photocatalysts in modulating redox half-reactions in photosynthesis.

Synthesis, Structure, White-Light Emission, and Temperature Recognition Properties of Eu/Tb Mixed Coordination Polymers.

Two series of Eu(III)/Tb(III) coordination polymers, [LnL(glu)]n·2nH2O (Ln = Eu (1), Tb (2)) and [LnL(glu)(H2O)]n (Ln = Eu (3), Tb (4)) [HL = (2-(2-sulfophenyl)imidazo(4,5-f)(1,10)-phenanthroline, H2glu = glutaric acid] have been hydrothermally synthesized by controlling the pH values and characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. Isomorphic compounds 1 and 2 exhibit 6-connected 3D network with the pcu topological net, containing left- and right-handed helical chains. Isomorphic compounds 3 and 4 show 3,4-connected 2D new topology with the point symbol of (4(2)·6(3)·8)(4(2)·6). Multicolor luminescence can be tailored from red to green regions by singly varying the mixing molar ratio of Eu(III)/Tb(III) cations. The mixing component of 1Eu/2Tb = 4:6 not only achieves white-light emission with the CIE coordinate of (0.323, 0.339) upon excitation at 405 nm but also presents a temperature recognition property with the significantly high sensitivity of 0.68% per K in the 50-225 K temperature range upon excitation at 370 nm.

The effect of the spacer of bis(biurea) ligands on the structure of A2 L3 -type (A=anion) phosphate complexes.

By tuning the length and rigidity of the spacer of bis(biurea) ligands L, three structural motifs of the A2 L3 complexes (A represents anion, here orthophosphate PO4 (3-) ), namely helicate, mesocate, and mono-bridged motif, have been assembled by coordination of the ligand to phosphate anion. Crystal structure analysis indicated that in the three complexes, each of the phosphate ions is coordinated by twelve hydrogen bonds from six surrounding urea groups. The anion coordination properties in solution have also been studied. The results further demonstrate the coordination behavior of phosphate ion, which shows strong tendency for coordination saturation and geometrical preference, thus allowing for the assembly of novel anion coordination-based structures as in transition-metal complexes.

Direct asymmetric dearomatization of 2-naphthols by scandium-catalyzed electrophilic amination.

Catalytic asymmetric aminative dearomatization of 1-substituted 2-naphthols was successfully implemented with electrophilic azodicarboxylates under the catalysis of chiral Sc(III)/pybox complexes. This intermolecular reaction represents a hitherto unknown enantioselective C-N bond-forming process through direct dearomatization of phenolic compounds to generate chiral nitrogen-containing quaternary carbon stereocenters.

Double sandwich polyoxometalate and its Fe(III) substituted derivative, [As2Fe5Mo21O82]17­ and [As2Fe6Mo20O80(H2O)2]16­.

A double sandwich polyoxometalate and its Fe(III) substituted derivative, [As(2)Fe(5)Mo(21)O(82)](17-) (1) and [As(2)Fe(6)Mo(20)O(80)(H(2)O)(2)](16-) (2), were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, fluorescent spectroscopy, UV spectra, thermogravimetry-differential scanning calorimetry analyses, electrospray ionization mass spectrometry, and magnetism measurements. The polyoxoanion is composed of a central fragment FeMo(7)O(28) for 1 (Fe(2)Mo(6)O(26)(H(2)O)(2) for 2) and two external AsMo(7)O(27) fragments linked together by two distinct edge-sharing dimeric clusters Fe(2)O(10) to lead to a C(2v) molecular symmetry. The central FeMo(7)O(28) fragment and external AsMo(7)O(27) fragment have a similar structure, and both of them can be viewed as a monocapped hexavacant α-Keggin subunit with a central FeO(4) group or a central AsO(3) group. Both of the polyoxoanions contain a oxo-bridged Fe(III)(5) magnetic core with the angles of Fe-O-Fe in the range of 96.4(4)-125.7(5)°, and magnetism measurements show an overall ferromagnetic interactions among the five-nuclearity cluster Fe(5) with the spin ground state S = 15/2.

A cagelike polyanion with a Ag+ enwrapped, [AgAs2Mo15O54]11-.

The polyanion [AgAs(2)Mo(15)O(54)](11-) has an unusual cage-like structure composed of [AsMo(6)O(27)](15-) and [AsMo(6)O(24)](9-) subunits connected by three MoO(4) tetrahedra, and a Ag(+) cation is inclosed at the center of the cage and coordinated by two As atoms with a As-Ag-As bond angle of 180° along with three µ(3)-oxo groups from MoO(4) tetrahedra to lead to a trigonal-pyramidal coordination geometry. The compound was also characterized by IR, X-ray photoelectron spectroscopy, fluorescent spectroscopy, and thermogravimetry-differential scanning calorimetry. The stability of [AgAs(2)Mo(15)O(54)](11-) in aqueous solution was investigated by using electronic absorbance spectroscopy and electrospray ionization mass spectrometry.

Three banana-shaped arsenomolybdates encapsulating a hexanuclear transition-metal central magnetic cluster: [As(III)2Fe(III)5MMo22O85(H2O)]n- (M = Fe3+, n = 14; M = Ni2+ and Mn2+, n = 15).

Three polyoxometalates encapsulating high-nuclearity magnetic clusters MFe(5), [As(2)MFe(5)Mo(22)O(85)(H(2)O)](n-) (M = Fe(3+), n = 14; M = Ni(2+) and Mn(2+), n = 15), were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis, and magnetism measurements. The polyanion [As(2)MFe(5)Mo(22)O(85)(H(2)O)](n-) consists of a central MMo(7)O(28) (M = Fe(3+), Ni(2+), and Mn(2+)) fragment and two AsMo(7)O(27) fragments linked together by two trimeric clusters, Fe(2)MoO(µ(2)-O)(2) and Fe(3)(H(2)O), to form a banana-shaped structure with C(1) symmetry. The MMo(7)O(28) and AsMo(7)O(27) units have a similar structure and can be considered as a monocapped hexavacant α-B-Keggin subunit with a central MO(4) group or a central As(III)O(3) group. The polyoxometalates have a low absorption of υ(Mo-O(d)) (925-913 cm(-1)) because most of the Mo atoms in the polyanions have at least two longer Mo-O(d) bonds. The framework of the arsenomolybdates is stable before As(2)O(3) escaping (ca. 300 °C). The analysis of magnetostructural correlations and magnetism measurements indicate the coexistence of ferro- and antiferromagnetic interactions, which give an overall ferromagnetic spin ground state in the compounds.

Pyridinium [2,6-bis-(5-phenyl-1H-pyrazol-3-yl-κN)pyridine-κN]tetra-nitrato-κO,O';κO-samarium(III) pyridine monosolvate.

In the title compound, (C(5)H(6)N)[Sm(NO(3))(4)(C(23)H(17)N(5))]·C(5)H(5)N, the Sm(III) atom is ten-coordinated by the N,N',N''-tridentate bis-(pyrazole) ligand and seven O atoms from four nitrate anions (three bidentate and one monodentate). The dihedral angles between the central pyridine ring and adjacent pyrazole rings in the ligand are 1.3 (2) and 3.2 (2)°; the dihedral angles between the pyrazole rings and their pendant phenyl rings are 42.0 (3) and 16.1 (2)°. The conformation of the anionic complex ion is supported by an intra-molecular N-H⋯O hydrogen bond. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds occur. The pyridinium cation forms an N-H⋯N hydrogen bond.

Diaqua-(2,2'-bipyridine-6,6'-dicarboxyl-ato)nickel(II).

In the title compound, [Ni(C(12)H(6)N(2)O(4))(H(2)O)(2)], the Ni(II) atom (site symmetry 2) displays a distorted cis-NiN(2)O(4) octa-hedral coordination geometry with two N atoms and two O atoms of the tetra-dentate 2,2'-bipyridine-6,6'-dicarboxyl-ate ligand in the equatorial plane and two water mol-ecules in axial positions. The complete dianionic ligand is generated by crystallographic twofold symmetry. In the crystal, a two-dimensional supra-molecular structure parallel to (001) is formed through O-H⋯O hydrogen-bond inter-actions between the coordinated water mol-ecules and the O atoms of nearby carboxyl-ate groups.

Europium(III) Complex-Functionalized SiO2@mTiO2 Nanospheres for Al3+-Modulated Multicolor Emission.

A europium(III) hybrid material Eu(tta)3bpdc-SiO2@mTiO2 (Htta = 2-thenoyltrifluoroacetone, H2bpdc = 2,2'-bipyridine-3,3'-dicarboxylic acid) was successfully designed and synthesized by the covalent grafting complex Eu(tta)3bpdc to SiO2@mTiO2 core-shell nanosphere. The FT-IR, PXRD, XPS, TEM, HRTEM, SAED, TGA and PL were performed to characterize these materials. The results indicate that core-shell nanosphere structure and anatase crystallites of SiO2@mTiO2 are retained well after grafting the europium complex. Hybrid material Eu(tta)3bpdc-SiO2@mTiO2 displays uniform nanosphere structure, bright red color and long lifetime, which can serve as a multicolor emission material modulated by using Al3+ ions via the cation exchange approach under a single-wavelength excitation. To the best of our knowledge, this work is the first multicolor emissive sensor for Al3+ ions based on the lanthanide hybrid material.

AsMo7O27-bridged dinuclear sandwich-type heteropolymolybdates of Cr(III) and Fe(III): magnetism of [MM'(AsMo7O27)2]12- with MM' = FeFe, CrFe, and CrCr.

Two new dinuclear sandwich-type heteropolymolybdates based on the mulitidendate inorganic fragment [AsMo(7)O(27)] and Cr(III) and Fe(III) ions, namely, the homometallic sandwich polyoxometalate (POM) (NH(4))(12)[Fe(2)(AsMo(7)O(27))(2)] x 12 H(2)O (1) and the first example of the "symmetrical" heterometallic Cr(III)-Fe(III) sandwich POM, (NH(4))(12)[FeCr(AsMo(7)O(27))(2)] x 13 H(2)O (2), were simultaneously synthesized in high yield. Their magnetic properties are thoroughly investigated together with the homometallic sandwich POM (NH(4))(12)[Cr(2)(AsMo(7)O(27))(2)] x 11 H(2)O (3). The chi(M)T values for compounds 1-3 at 300 K correspond well to the calculated spin-only values for Fe(III) (S = 5/2) and Cr(III) (S = 3/2) with g(Fe) = g(Cr) = 2. Upon cooling, the chi(M)T values decline monotonously and reach 0.14, 1.00, and 0.11 cm(3) K mol(-1) at 2.0 K for 1, 2, and 3, respectively, indicating a significant antiferromagnetic exchange between the magnetic centers with J = -2.09, -4.09, and -6.26 cm(-1), respectively, for 1, 2, and 3. The magnetic results clearly establish that compound 2 is formed by bimetallic Cr(III)-Fe(III) units and not by a mixture of the two antiferromagnetically coupled homometallic species. Their thermal properties are also characterized.

Dy(iii) zig-zag chains assembled in a 3D framework with single-molecule magnet behaviour.

A new lanthanide-based framework, [Dy(STP)(1,2-bdc)]n (1), was constructed. It represents dysprosium(iii) 1D zigzag chains in a 3D framework and displays single-molecule magnet (SMM) behaviour with an energy barrier of 55.76 K under zero dc field.

A large, X-shaped polyoxometalate [As6Fe7Mo22O98]25- assembled from [AsMo7O27]9- and [FeMo4O19]11- moieties.

A large X-shaped polyoxometalate, [As6Fe7Mo22O98]25- (1), has been synthesized and structurally characterized. The skeleton of 1 is composed of two monocapped hexavacant Keggin [AsMo7O27]9- units and two divacant Anderson [FeMo4O19]11- units fused together through a central Fe5O4 core and two µ4-As2O bridging units, resulting in a unique tetramer with C2h symmetry. The polyanion represents the largest iron-containing arsenomolybdate to date and it contains an unprecedented heptanuclear iron(iii) cluster. The investigation of the magnetic properties shows that the Fe7 cluster exhibits an overall ferromagnetic interaction with a spin ground state of S = 7.5.

Lanthanide coordination frameworks constructed from 3,3',4,4'-diphenylsulfonetetracarboxylic and 1,10-phenanthroline: synthesis, crystal structures and luminescence properties.

Two series of lanthanide coordination polymers, [Ln(Hdpstc)(H2O)2]n·nH2O (Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7), Yb (8)) and [Ln(Hdpstc)(phen)(H2O)]n·1.5nH2O (Ln = Pr (9), Nd (10), Eu (11), Tb (12)) (H4dpstc = 3,3',4,4'-diphenylsulfonetetracarboxylic acid and phen = 1,10-phenanthroline), have been hydrothermally synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. Isostructural compounds 1-8 and 9-12 exhibit (3,6)-connected 2D layered structures with Hdpstc3- anions as bridges. The Eu3+ and Tb3+ compounds exhibit bright red and green emissions with absolute quantum yields of 11.19% for 2-Eu, 26.05% for 4-Tb, 35.74% for 11-Eu, and 48.05% for 12-Tb. With a rational design strategy, we have constructed a series of Tb3+-doped Eu3+ materials emitting tunable three primary colors towards efficient white light emission with compounds 2-Eu and 4-Tb, and the absolute quantum yield of white light emission is 13.58%. Meanwhile, 4-Tb displays a highly sensitive response toward Fe3+ ions through significant fluorescence quenching of Tb3+.

1D silver(I) complex of nitronyl nitroxide with strong spin-spin interaction through silver(I) ion.

A 1D silver(I) complex of nitronyl nitroxide was prepared and its structure was determined by X-ray diffraction analysis; magnetic studies indicate that the spin-spin interaction of nitronyl nitroxides through silver(I) ions along the chain are fairly strong (J/kb = -84 K).

An unusual fan-type polyanion with a silver cation located at the axial center, [AgAsIII2(AsIIIAsVMo4O18(OH)2)3]11-.

A new type of polyoxomolybdate containing mixed-valence arsenic, [AgAs(III)(2)(As(III)As(V)Mo(4)O(18)(OH)(2))(3)](11-) (1), has been synthesized. Single-crystal X-ray analysis was carried out on (NH(4))(5)(C(2)H(9)N(2))(4.5)H(1.5)[AgAs(III)(2)(As(III)As(V)Mo(4)O(18)(OH)(2))(3)]·14H(2)O (1a) and (NH(4))(11)[AgAs(III)(2)(As(III)As(V)Mo(4)O(18)(OH)(2))(3)]·16H(2)O (1b). The polyanion is composed of three unprecedented [As(III)As(V)Mo(4)O(18)(OH)(2)](6-) subunits linked together by two AsO(3) trigonal-pyramidal structures from both sides via sharing six bridging oxygen atoms, and a silver cation is enclosed in the center of the polyanion and coordinated by three As atoms with the As-Ag-As bond angle of 120°, to lead to a fan-like structure with an approximative C(3h) symmetry. The polyanion was also characterized by IR, X-ray photoelectron spectroscopy and thermogravimetry-differential scanning calorimetry. The stability of [AgAs(III)(2)(As(III)As(V)Mo(4)O(18)(OH)(2))(3)](11-) in an aqueous solution was investigated by electronic absorbance spectroscopy and electrospray ionization mass spectrometry, and the possible disaggregation mechanism of the polyanion is proposed.

Diruthenium(III,III) diphosphonate with a spin ground state S = 2.

Complexes containing a Ru(2)(n+) core (n = 4, 5 or 6) have been of great interest because of their variety of electronic configurations and magnetic properties. Herein, we report a novel homovalent Ru(2)(6+)-based complex, (H(2)pip)(2)[Ru(2)(hedp)(2)Cl(2)]·6H(2)O (pip = piperazine) (1), isolated by the direct reaction of the mixed-valent Ru(2)(5+)-based anion Ru(2)(hedp)(2)(3-) [hedp = 1-hydroxyethylidenediphosphonate, CH(3)C(OH)(PO(3))(2)] with oxidant peracetic acid under room temperature conditions. Magnetic measurements unambiguously confirm that this complex contains four unpaired electrons with a spin ground state of S = 2.

Single-molecule magnet based on a C-type polyoxomolybdate with an S = 11 ground state: [Fe5CoMo22As2O85(H2O)]15-.

A C-type polyoxomolybdate containing a mixed-transition metal cluster Fe(5)Co has been prepared as an ammonium salt, (NH(4))(15)[Fe(5)CoMo(22)As(2)O(85)(H(2)O)]·15H(2)O (1). Interestingly, the magnetism measurements show that the compound exhibits not only an overall ferromagnetic cluster with a large spin ground state of S = 11 but also the behavior of single-molecule magnets.

A diruthenium soft ferromagnet showing T(c) = 3.0 K: Mn4(H2O)16H[Ru2(CO3)4]2[Ru2(CO3)4(H2O)2]·11H2O.

A three-dimensional CO(3)(2-)-bridged Mn(II)-Ru(2)(II,III) complex, Mn(4)(H(2)O)(16)H[Ru(2)(CO(3))(4)](2)[Ru(2)(CO(3))(4)(H(2)O)(2)]·11H(2)O (1), was synthesized by self-assembling Ru(2)(CO(3))(4)(3-) paddle-wheel precursors and Mn(2+) cations. It contains an unprecedented layer [Ru(2)(CO(3))(4)](n)(3n-) with (4,4) network. The ferromagnetic coupling between spin centers results in ordering below 3.0 K.

Auxiliary ligand-directed structural variation from 2D→3D polythreaded net to 3-fold interpenetrating 3D pillar-layered framework: syntheses, crystal structures and magnetic properties.

By auxiliary N-donor ligand-directed assembled, two entangled Co(II)-coordination nets have been constructed from 3,3',5,5'-azobenzenetetracarboxylic acid (H(4)abtc), which present a rare 2D→3D polythreading motif constructed from 2-fold (6,3) polymeric layers with thickness being 10.2 Šand a 3-fold interpenetrating pillar-layered framework based on linear trinuclear Co(II)-SBUs. In addition, two Co(II)-complexes both show an antiferromagnetic coupling by long organic spacers and H(2)O bridges, respectively.