Showing papers by "Jiang-Gao Mao published in 2015"
TL;DR: Pb-layered perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours, and this finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.
Abstract: Inorganic semiconductor ferroelectrics such as BiFeO3 have shown great potential in photovoltaic and other applications. Currently, semiconducting properties and the corresponding application in optoelectronic devices of hybrid organo-plumbate or stannate are a hot topic of academic research; more and more of such hybrids have been synthesized. Structurally, these hybrids are suitable for exploration of ferroelectricity. Therefore, the design of molecular ferroelectric semiconductors based on these hybrids provides a possibility to obtain new or high-performance semiconductor ferroelectrics. Here we investigated Pb-layered perovskites, and found the layer perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours. It has a larger ferroelectric spontaneous polarization Ps=13 μC cm(-2) and a higher Curie temperature Tc=438 K with a band gap of 3.65 eV. This finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.
466 citations
TL;DR: In this paper, the second-order nonlinear optical properties of metal iodates are discussed and a review of metal ion structures and secondorder NLO properties are discussed. But the authors do not consider the effect of the polarizations from both types of the asymmetric units are aligned properly.
239 citations
TL;DR: A new SHG material, namely, Pb2(BO3)(NO3), which contains parallel π-conjugated nitrate and borate anions, was obtained through a facile hydrothermal reaction by using Pb(NO3)2 and Mg(BO2)2⋅H2O as starting materials.
Abstract: A new SHG material, namely, Pb2(BO3)(NO3), which contains parallel π-conjugated nitrate and borate anions, was obtained through a facile hydrothermal reaction by using Pb(NO3)2 and Mg(BO2)2⋅H2O as starting materials. Its structure contains honeycomb [Pb2(BO3)]∞ layers with noncoordination [NO3](-) anions located at the interlayer space. Pb2(BO3)(NO3) shows a remarkable strong SHG response of approximately 9.0 times that of potassium dihydrogen phosphate (KDP) and the material is also phase-matchable. The large SHG coefficient of Pb2(BO3)(NO3) arises from the synergistic effect of the stereoactive lone pairs on Pb(2+) cations and parallel alignment of π-conjugated BO3 and NO3 units. Based on its unique properties, Pb2(BO3)(NO3) may have great potential as a high performance NLO material in photonic applications.
218 citations
TL;DR: In this article, a new layered organic cobalt phosphonate crystal, Co3(O3PCH2-NC4H7-CO2)2·4H2O (1) was synthesized and demonstrated it as a heterogeneous catalyst for water oxidation.
Abstract: The development of artificial photosynthesis systems that can efficiently catalyze water oxidation to generate oxygen remains one of the most important challenges in solar energy conversion to chemical energy. In photosystem II (PSII), the Mn4CaO5 cluster adopts a distorted coordination geometry and every two octahedra are linked by di-μ-oxo (edge-shared) or mono-μ-oxo (corner-shared) bridges, which is recognized as a critical structure motif for catalytic water oxidation. These structural features provide guidance on the design and synthesis of new water oxidation catalysts. Herein we synthesized a new layered organic cobalt phosphonate crystal, Co3(O3PCH2–NC4H7–CO2)2·4H2O (1) and demonstrate it as a heterogeneous catalyst for water oxidation. Its catalytic activity was compared to those of cobalt phosphonates with different structures (2–4) in terms of O2 evolution rate and O2 yield under the same reaction conditions. The compound with both mono- and di-μ-oxo bridged octahedral cobalt displays superior catalytic activity. In contrast, the presence of only mono-μ-oxo bridged cobalt in the structure results in lower O2 yield and O2 evolution rate. Further structural analysis reveals that the presence of a longer Co–N bond induces a distorted dissymmetry coordination geometry, and consequently facilitates water oxidation. These results provide important insight into the design of water oxidation catalysts.
76 citations
TL;DR: Two new cesium selenites containing TaO6 or TiO4F2 octahedra and Cs(TiOF)3(SeO3)2, prepared using standard high temperature solid-state method and hydrothermal reaction, have been prepared and relationship between crystal structure and SHG, and theoretical calculations were also reported.
Abstract: Two new cesium selenites containing TaO6 or TiO4F2 octahedra, namely, Cs(TaO2)3(SeO3)2 (1) and Cs(TiOF)3(SeO3)2 (2), have been prepared using standard high temperature solid-state method and hydrothermal reaction, respectively. Compound 1 crystallizes in P3m1 and features an unusual [(TaO2)3(SeO3)2]− sandwich-like double layer in which two [Ta(1)O3(SeO3)]3– layers are bridged by central Ta(2)O6 octahedra via corner-sharing, whereas Cs(TiOF)3(SeO3)2 with a polar space group P63mc features an interesting hexagonal tungsten oxide (HTO) layered topology and presents a strong second harmonic generation (SHG) of about 5 × KDP (KH2PO4), which is much larger than those of A(VO2)3(QO3)2 (A = K, Tl, Rb, Cs, or NH4; Q = Se, Te) with a similar HTO layered structure. Cs(TiOF)3(SeO3)2 is also type-I phase matching. The SHG of above-mentioned HTO materials can be enhanced greatly with the replacement of VO6 octahedra by TiO4F2 octahedra. Furthermore, thermal stabilities, UV–vis diffuse reflectance spectra, infrared spe...
54 citations
TL;DR: The first examples of metal borotellurates have been prepared by using solid-state reactions and results of magnetic measurements indicate that they display weak antiferromagnetic interaction between RE(III) centers.
Abstract: The first examples of metal borotellurates, namely, Na2RE2TeO4(BO3)2 (RE = Y, Dy-Lu) have been prepared by using solid-state reactions. They possess similar structures and crystallize in space group P21/c (No. 14). These compounds feature a novel [RE2TeO4(BO3)2](2-) 3D network structure composed of linear [TeO4(BO3)2](8-) anions interconnected by RE(3+) ions with the voids of the network filled by the Na(+) ions. They exhibit high thermal stability (higher than 800 °C). Results of magnetic measurements on Dy, Ho, and Er compounds indicate that they display weak antiferromagnetic interaction between RE(III) centers. Luminescent studies show that Na2Er2TeO4(BO3)2 has a strong emission at 1.562 μm with a wide fwhm (70 nm) and moderate lifetime (0.18 ms), whereas Na2Yb2TeO4(BO3)2 has a strong NIR region emission around 1.02 μm. Furthermore, UV-vis-NIR absorption spectra, infrared spectra, and DFT calculations for the Y compound as a representative were also accomplished.
39 citations
TL;DR: The first examples of lanthanide borate-acetate mixed anion compounds, namely, Ln2(CH3CO2)2[B5O9(OH)]·H2O (Ln = La 1; Ce 2; Pr 3), were synthesized under hydrothermal conditions and display a unique three-dimensional (3D) framework built by a 3D network of Lanthanideborate borate further decorated by acetate anions.
Abstract: The first examples of lanthanide borate–acetate mixed anion compounds, namely, Ln2(CH3CO2)2[B5O9(OH)]·H2O (Ln = La 1; Ce 2; Pr 3), were synthesized under hydrothermal conditions. These compounds are isostructural and crystallize in polar space group Cc. They display a unique three-dimensional (3D) framework built by a 3D network of lanthanide borate further decorated by acetate anions. The borate anion exhibits a 2D layer in the ac plane with large 9-member rings (MRs) which are filled by lanthanide(III) ions into a {Ln[B5O9(OH)]}− 2D layer. Adjacent {Ln[B5O9(OH)]}− layers are bridged by remaining lanthanide (III) ions to form a 3D network of lanthanide borate. It is noteworthy that Ln2(CH3CO2)2[B5O9(OH)]·H2O (Ln = La 1; Ce 2; Pr 3) can be changed into Ln2(CH3CO2)2[B5O9(OH)] (Ln = La 4; Ce 5; Pr 6) under heating at 500 K. Compounds 1–4 display moderate SHG signals of about 2.0, 1.0, 1.4, and 2.5 times that of KH2PO4, respectively, and they are phase matchable. Their SHG responses mainly arise from the syn...
35 citations
TL;DR: UV-vis diffuse reflectance spectroscopy studies show that the short-wavelength absorption edges of KCdCO3F and K2Pb3(CO3)3F2 are 227 and 287 nm, respectively, and this material is a promising UV material for fourth harmonic generation on a 1064 nm Q-switched Nd:YAG laser.
Abstract: Two new mixed metal fluoride carbonates, KCdCO3F and K2Pb3(CO3)3F2, have been synthesized by solvothermal and solid-state techniques. KCdCO3F crystallizes in the acentric nonpolar space group P6m2, and its structure features a three-dimensional anionic framework in which the CdCO3 layers are further interconnected by bridging F(-) anions with the negative charge balanced by K(+) cations. K2Pb3(CO3)3F2 crystallizes in the centrosymmetric space group P63/mmc, and its structure exhibits a layered anionic skeleton featuring corner-shared PbO6F and PbO6F2 polyhedra. UV-vis diffuse reflectance spectroscopy studies show that the short-wavelength absorption edges of KCdCO3F and K2Pb3(CO3)3F2 are 227 and 287 nm, respectively. The second harmonic generation (SHG) measurement reveals that KCdCO3F is a phase-matchable material for generation of doubled-frequency light at both 532 and 266 nm, with a large SHG response of approximately 5.2 times that of KH2PO4 (KDP) at 532 nm and a moderate SHG response of approximately 0.75 times that of β-BaB2O4 (BBO) at 266 nm. Therefore, it is a promising UV material for fourth harmonic generation on a 1064 nm Q-switched Nd:YAG laser.
35 citations
TL;DR: In this article, single crystals of Pb2(BO3)(NO3) were prepared by hydrothermal reaction of pb(NO 3)2 and Mg(BO2)2 at pH 5.0-5.5 (autoclave, 210 °C, 4 d; 85% yield).
Abstract: Single crystals of Pb2(BO3)(NO3) are prepared by hydrothermal reaction of Pb(NO3)2 and Mg(BO2)2 at pH 5.0-5.5 (autoclave, 210 °C, 4 d; 85% yield).
32 citations
TL;DR: Experimental results for two new sodium selenites containing a second-order Jahn-Teller distorted Nb(5+) cation are consistent with those based on DFT theoretical calculations and Thermal stabilities and optical properties for both compounds are reported.
Abstract: Standard high-temperature solid-state reactions of NaCl, Nb2O5, and SeO2 resulted in two new sodium selenites containing a second-order Jahn–Teller (SOJT) distorted Nb5+ cation, namely, Na2Nb4O7(SeO3)4 (P1; 1) and NaNbO(SeO3)2 (Cmc21; 2). Compound 1 exhibits an unusual 3D [Nb4O7(SeO3)4]2– anionic network composed of 2D [Nb4O11(SeO3)2]6– layers which are further bridged by additional SeO32– anions via corner sharing; the 2D [Nb4O11(SeO3)2]6– layer is formed by unusual quadruple [Nb4O17]14– niobium oxide chains of corner-sharing NbO6 octahedra being further interconnected by selenite anions via Nb–O–Se bridges. The polar compound 2 features a 1D [NbO(SeO3)2]− anionic chain in which two neighboring Nb5+ cations are bridged by one oxo and two selenite anions. The alignments of the polarizations from the NbO6 octahedra in 2 led to a strong SHG response of ∼7.8 × KDP (∼360 × α-SiO2), which is the largest among all phases found in metal–Nb5+–Se4+/metal–Nb5+–Te4+–O systems. Furthermore, the material is also type...
26 citations
TL;DR: In this paper, a new lead phosphite, Pb 2 (HPO 3 ) 2, crystallizes in the noncentrosymmetric space group C mc2 1 (no. 36), which features 3D framework formed by the interconnection of 2D layer of lead(II) phosphites and 1D chain of [Pb(HPO3 ) 5 ] ∞.
TL;DR: In this article, three new lead-II borate oxo-nitrates were obtained through a facile hydrothermal reaction by adjusting the concentrations of the starting materials, namely, [Pb6(μ4-O)4(BO3)](NO3) (1), H[Pb 6(μ3-O),2,BO3)2,2]2,3,2]-NO3 (2), and H[pb8(μ 4,O),3,O,4,O)(BO3),2]-
Abstract: Three novel lead(II) borate–nitrates were obtained through a facile hydrothermal reaction by adjusting the concentrations of the starting materials, namely, [Pb6(μ4-O)4(BO3)](NO3) (1), H[Pb6(μ3-O)2(BO3)2](NO3)3 (2) and H[Pb8(μ4-O)3(μ3-O)(BO3)2](NO3)3 (3). All three compounds feature lead(II) oxo borate layers that are separated by nitrate anions. The 2D [Pb6(μ4-O)4(BO3)]+ layer parallel to the ab plane in 1 is built from 1D [Pb6(μ4-O)4]4+ chains along the a axis and bridging borate anions. The 2D H[Pb6(μ3-O)2(BO3)2]3+ layer in 2 which is perpendicular to the b axis is composed of “isolated” Pb2+ and tetranuclear [Pb4(μ3-O)2]4+ clusters interconnected by bridging BO3 groups. The [Pb8(μ4-O)3(μ3-O)(BO3)2]2+ (011) layer in 3 is composed of two types of lead(II) oxo chains, namely, 1D chains of [Pb4(μ4-O)2]4+ and 1D chains of [Pb4(μ4-O)(μ3-O)]4+, both elongated along the a axis, which are further interconnected by bridging borate anions. This study also demonstrates that a small change in the concentration of the starting materials could result in a product with a different density of the π-conjugated planar units.
TL;DR: Three new octanuclear Th(iv) arsonates have been prepared under hydrothermal conditions and display unusual broad green light emission bands at 523 nm and 517 nm, respectively, which originate from the ligand-to-metal charge transfer (LMCT) transition.
Abstract: Three new octanuclear Th(IV) arsonates, namely [Th8(O)(L)6(HL)6(H2O)12]·19.5H2O (1) (H3L = o-HO3S–C6H4–AsO3H2), [Th8(O)(L)6(HL)6(H2O)10]·17H2O (2) and [Th8(O)(L)6(HL)6(H2O)5]·0.5H2O (3), with o-sulfophenylarsonic acid as the bridging ligand, have been prepared under hydrothermal conditions. Each complex contains [Th8O13]6+ octanuclear cluster cores composed of two [Th4O6]4+ units bridged by a μ2-oxo anion. The structure of compound 1 features a 0D highly symmetric polynuclear cluster encapsulating the octanuclear core of [Th8O13]6+ which is further decorated by six L3− and six HL2− ligands. Compound 2 features one-dimensional chains along the b-axis in which the neighboring clusters similar to 1 are bridged by a pair of sulfophenylarsonate ligands via M–O–S–O–M bridges. Compound 3 with chiral P212121 features two-dimensional cluster layers, in which each cluster connects with four neighbors via four M–O–S–O–M linkages. Compounds 2 and 3 display unusual broad green light emission bands at 523 nm (λex = 320 nm) and 517 nm (λex = 312 nm), respectively, which originate from the ligand-to-metal charge transfer (LMCT) transition.
TL;DR: In this paper, a large crystal of the nonlinear optical and polar oxide Cs2TeW3O12 with a size of 20×15×4mm3 has been grown by the top-seeded solution growth (TSSG) method.
TL;DR: In this paper, three transition metal copper(II) selenites or tellurites were obtained by conventional hydrothermal reactions of CdO (or Hg2Cl2), CuO and SeO2 (or TeO2), and their structures feature a 3D anionic framework of Cu(SeO3)22− with 1D channels of eight-membered rings (MRs) along the c-axis and a-axis, respectively.
Abstract: Three new transition metal copper(II) selenites or tellurites, namely, CdCu(SeO3)2 (1), HgCu(SeO3)2 (2), and Hg2Cu3(Te3O8)2 (3), have been obtained by conventional hydrothermal reactions of CdO (or Hg2Cl2), CuO and SeO2 (or TeO2). Compounds 1 and 2 are isostructural and crystallize in P21/c. Their structures feature a 3D anionic framework of Cu(SeO3)22− with 1D channels of eight-membered rings (MRs) along the c-axis and a-axis, respectively, which are filled by Cd2+ or Hg2+ cations. Compound 3 crystallizes in a tetragonal system of space group P4212. Its structure is characterized by a [Cu3(Te3O8)2]2− honeycomb layer composed of [Te3O8]4− anions interconnected by Cu2+ ions with 1D channels of 8-MRs along the c-axis. TOPOS analysis indicates that the copper(II) tellurite layer exhibits a new topological structure with a Schlafli symbol of {46·89}2{46}3. The above anionic copper(II) tellurite layers are further linked by dumbbell Hg22+ cations to form a novel 3D framework. Magnetic measurements based on magnetic susceptibility and heat capacity indicate that compounds 1 and 2 show a spin-singlet ground state with a spin gap based on the [Cu2O8]12− dimeric model, whereas compound 3 exhibits a 2D spin-system with an antiferromagnetic ordering around 25 K correlated with its honeycomb [Cu3(Te3O8)2]2− layer. Furthermore, crystalline structures, thermal stabilities, IR spectra and UV-Vis diffuse reflectance spectra have also been studied.
TL;DR: KCdCO3F (I) is prepared by solvothermal reaction of Cd(OAc)2, KF, and TFA in MeOH (Cd:K = 1:16; autoclave, 180 °C, 48 h; cooling to 20 °C at a rate of 2 °C/h, 63% yield) as discussed by the authors.
Abstract: KCdCO3F (I) is prepared by solvothermal reaction of Cd(OAc)2, KF, and TFA in MeOH (Cd:K = 1:16; autoclave, 180 °C, 48 h; cooling to 20 °C at a rate of 2 °C/h, 63% yield).
TL;DR: The new compounds (IV and VI) were characterized by single crystal XRD, IR and UV/VIS spectroscopy, second harmonic generation measurements, and DFT calculations as mentioned in this paper.
Abstract: The new compounds (IV) and (VI) are characterized by single crystal XRD, IR and UV/VIS spectroscopy, second harmonic generation measurements, and DFT calculations.
TL;DR: The title compounds were prepared by solid state reactions of Na2CO3, TeO2, H3BO3, and Ln2O3 (Ln: Y, Dy-Lu; Pt crucible, 830 °C, 10 d) as discussed by the authors.
Abstract: The title compounds are prepared by solid state reactions of Na2CO3, TeO2, H3BO3, and Ln2O3 (Ln: Y, Dy—Lu; Pt crucible, 830 °C, 10 d).
TL;DR: In this paper, large crystals of Cs2TeW3O12 (20 x 15 x 4 mm) were grown by the top-seeded solution growth method from mixtures of cs2Co3, TeO2, and WO3 (molar ratio of 2:5:3).
Abstract: Large crystals of Cs2TeW3O12 (20 x 15 x 4 mm) are grown by the top-seeded solution growth method from mixtures of Cs2TeW3O12 and Cs2O and TeO2 as a flux (molar ratio1:1:4) or Cs2CO3, TeO2, and WO3 (molar ratio of 2:5:3) (Pt crucible, 700 °C, 3 d).
TL;DR: In this paper, the new compound (III) crystallizes in the orthorhombic space group Cmc21 with Z = 8 (powder XRD) and Z = 4 (powder powder XRD).
Abstract: The new compound (III) crystallizes in the orthorhombic space group Cmc21 with Z = 8 (powder XRD).
TL;DR: The new title compounds (III and V) are characterized by single crystal XRD, IR, UV/VIS, and optical diffuse reflectance spectroscopy, second harmonic generation measurements, and DFT electronic band structure calculations as mentioned in this paper.
Abstract: The new title compounds (III) and (V) are characterized by single crystal XRD, IR, UV/VIS, and optical diffuse reflectance spectroscopy, second harmonic generation measurements, and DFT electronic band structure calculations.
TL;DR: The new compounds (IV, VI, (VI), (VII), and (VIII) are characterized by single crystal XRD, IR and UV spectroscopy, and DFT band structure calculations as mentioned in this paper.
Abstract: The new compounds (IV), (VI), (VII), and (VIII) are characterized by single crystal XRD, IR and UV spectroscopy, and DFT band structure calculations.