Kwang-Hwa Lii

National Central University | NCU · Department of Chemistry

Excitation, photoluminescence, and time‐resolved emission spectra of the Eu3+‐containing compounds, YxEu2‐x(CHDC)3, Eu(NO3)3·5H2O, and Eu2O3 were obtained. The coordination polymers, R2(C8H10O4)3, (R = Eu or Y), were synthesized by mid‐temperature hydrothermal technique with the 1,4‐cyclohexanedicarboxylate (C8H10O4, CHDC) ligands. Blue‐shift emiss...

An exploratory study of the lead-tellurium-oxygen phase space led to two new compounds, Ba3PbTe6O16 (BPTO) and Na2Pb9(μ6-O)2(Te2O10)2 (NPTO), which were synthesized under hydrothermal conditions at 550 °C and 210 °C, respectively, and characterized by single-crystal X-ray diffraction, infrared and X-ray photoelectron spectroscopy. BPTO adopts a lay...

A new lead(ii) borosilicate, Pb6B2Si8O25 (1), has been synthesized by a high-temperature, high-pressure hydrothermal reaction at 480 °C and 990 bar. Its structure was determined by single-crystal X-ray diffraction. The reaction product was phase-pure as indicated by powder X-ray diffraction and whole pattern fitting using the Pawley method. Compoun...

With a high-temperature, high-pressure hydrothermal technique, a new barium lead borate, [Ba3Pb(H2O)][B11O19(OH)3] (1), has been synthesized and characterized by single-crystal X-ray diffraction, infrared, and solid-state NMR spectroscopy. The structure of 1 contains a planar thick layers of borates with the Ba²⁺ cations at sites in the inter- and...

Two new barium hydroxyborosilicates, Ba2[Si3B3O12(OH)] (1) and Ba[Si2BO6(OH)] (2), have been synthesized by a flux method at 480 °C and characterized by single-crystal X-ray diffraction and infrared spectroscopy. Both compounds have 2D layer structures. Compound 1 contains planar slabs of borosilicate formed of tetrahedral building units which can...

Correction for ‘Ca 10 Na 10 [Te 9 O 42 ](H 2 O): a hydrothermally synthesized quaternary tellurium( vi ) oxide containing edge-sharing octahedral trimers’ by Li-Yun Zhang, et al. , Dalton Trans. , 2019, DOI: 10.1039/c9dt03521d.

A new tellurium(VI) oxycompound, Ca10Na10[Te9O42](H2O), was synthesized by high temperature, high-pressure hydrothermal reaction at 550 °C, its structure determined by single crystal X-ray diffraction, and further characterized by energy dispersive, infrared, and X-ray photoelectron spectroscopy. The compound crystallizes in the centrosymmetric tri...

Two polymorphs of a new barium borate, α- and β-Ba 3 [B 10 O 17 (OH) 2 ], have been synthesized through hydrothermal reactions at 500 °C and 1000 bar and their structures determined by single-crystal X-ray diffraction. The 3D framework structure of the α-form is formed of two different fundamental building blocks (FBB) with the descriptors 4Δ6□:[]-...

Two new barium borate carbonates, Ba3[B6O10(OH)2](CO3) (1) and Ba6[B12O21(OH)2](CO3)2 (2), have been synthesized by high-temperature, high-pressure hydrothermal methods at 460 °C and 600 bar and structurally characterized by single-crystal X-ray diffraction, TGA, IR, and MAS 11B NMR spectroscopy. The descriptors of the fundamental building blocks (...

A new borate fluoride, Ba2B5O9F·0.5H2O, has been synthesized by high-temperature, high-pressure hydrothermal method, characterized by a combination of techniques and its structure determined by single-crystal X-ray diffraction. The compound crystallizes in the noncentrosymmetric space group P4̅ n2 (No. 118) and powder SHG measurements were performe...

A new aluminum borate, Ba[AlB4O8(OH)], has been synthesized under high-temperature, high-pressure hydrothermal conditions at 550 °C and 1400 bar and its structure characterized by single-crystal X-ray diffraction, IR, and MAS 11B, and 27Al NMR spectroscopy. It crystallizes in the monoclinic space group P21/n with a = 7.0695(5) Å, b = 15.108(1) Å, c...

Two organozincophosphate polymorphs were obtained by incorporating the terephathalate organic ligand 1,4-benzenedicarboxylate (BDC) into the inorganic structures of metal phosphates via hydro(solvo)thermal methods at different reaction temperatures and structurally characterized by single-crystal X-ray diffraction. Remarkably, the bis-monodentate B...

Four new uranyl silicates with the same framework composition but different crystal structures, Na2[(UO2)Si4O10]·0.5H2O (1), K2[(UO2)Si4O10] (2), Rb2[(UO2)Si4O10] (3), and Cs2[(UO2)Si4O10] (4), have been synthesized under supercritical hydrothermal conditions at 590 °C and 1620 bar and characterized by single-crystal X-ray diffraction and infrared...

The search for new and efficient nonlinear optical (NLO) materials has been an active research because of their technological importance in laser applications. Although a large number of frequency-doubling oxides, phosphates, borates, and fluoride-containing borates were found, no transition-metal silicate with useful NLO properties has been report...

The new mixed alkali metal uranyl silicates (V), (VII), and (VIII) are characterized by single crystal XRD.

A new uranyl silicate, K2Ca4[(UO2)(Si2O7)2], with a 1D chain structure has been synthesized from a solution of mixed alkali- and alkaline-earth-metal cations under hydrothermal conditions at 550 °C and 1400 bar and characterized by single-crystal X-ray diffraction and photoluminescence spectroscopy. It crystallizes in the triclinic space group P1̅...

Three mixed-alkali metals uranyl silicates, Na3K3[(UO2)3(Si2O7)2]·2H2O (1), Na3Rb3[(UO2)3(Si2O7)2] (2), and Na6Rb4[(UO2)4Si12O33] (3), have been synthesized by high-temperature, high-pressure hydrothermal reactions at 550°C and 1440bar, and characterized by single-crystal X-ray diffraction, photoluminescence, and thermogravimetric analysis. Compoun...

A new zinc phosphite exhibited remarkable structural transformations upon heat stimulation to convert into a dehydrated form (NCU-2a) and a new structure, NCU-2b. The gas adsorption properties of the materials as well as the luminescence properties of LED devices fabricated using these materials were also investigated.

An organic-inorganic hybrid zinc phosphate with 28-ring channels was synthesized by use of an organic ligand instead of organic amine template under a hydro(solvo)thermal condition. This crystalline zinc phosphate contains large channels constructed from 28 zinc and phosphate tetrahedral units. The walls of the channels consist of two types of zinc...

The solid solutions (V1-xWx)OPO4 with β-VOPO4 structure (0.0 ≤ x ≤ 0.01) and αII-VOPO4 (tetragonal space group P4/n, Z = 2) structure (0.04 ≤ x ≤ 0.26) are obtained from mixtures of VOPO4 and WOPO4 by conventional solid state reaction in the presence of Cl2 as mineralizer (silica ampoule, 800 °C, 7 d).

Five new uranyl arsenates, Na14[(UO2)5(AsO4)8]·2H2O (1), K6[(UO2)5O5(AsO4)2] (2a), K4[(UO2)3O2(AsO4)2] (2b), Rb4[(UO2)3O2(AsO4)2] (3), and Cs6[(UO2)5O2(AsO4)4] (4), were synthesized by high-temperature, high-pressure hydrothermal reactions at about 560 °C and 1440 bar and were characterized by single-crystal X-ray diffraction, thermogravimetric ana...

Most uranium minerals can be classified as oxidized species in which U is fully oxidized to U(VI), and reduced species, in which U occurs primarily as U(IV). Uranyl silicates are an important group of uranium(VI) minerals in the altered zones of many uranium deposits [1]. Uranyl silicates have also received attention because they form when spent nu...

The solid solutions (V1–xWx)OPO4 with β-VOPO4 structure type (0.0 ≤ x ≤ 0.01) and αII-VOPO4 structure type (0.04 ≤ x ≤ 0.26) were obtained from mixtures of VVOPO4 and WVOPO4 by conventional solid state reactions and by solution combustion synthesis. Single crystals of up to 3 mm edge length were obtained by chemical vapor transport (CVT) (800 → 700...

Layered vanadyl phosphate hydrates with the V/P ratio of 1:1 represent an important class of low-dimensional phosphate structures as they are of great interest in intercalation chemistry in association with redox catalytic reactions and innovation of light and energy-saving materials. The inorganic layer of VOPO4 is simple chemically, but is actual...

Nanostructured zinc phosphite templated by cetyltrimethylammonium (CTA(+)) cations was synthesized using a hydro(solvo)thermal method. This is the first example of a crystalline metal phosphite containing long carbon tails of the CTA(+) ions as templates in its structure, as is structurally characterized by single-crystal X-ray diffraction. The 2D...

The isotypic compounds (III) and (V) are characterized by single crystal XRD, UV/VIS spectroscopy, and XPS.

The title compound is solvothermally synthesized from a mixture of In(NO3)2, GeO2, H3BO3, 1,2-diaminopropane, and HF in H2O/pyridine (autoclave, 170 °C, 10 d).

A new indium borogermanate incorporating an organic amine ligand, InBGe2O6(OH)2(CH3CH(NH2)CH2NH2)·2H2O, was synthesized under solvothermal conditions and characterized by infrared spectroscopy, thermogravimetric analysis, and emission spectroscopy. This compound is a new example of the combination of metal, boron, and germanium atoms into one struc...

A uranium(IV) phosphate, Na10U2P6O24, was synthesized under hydrothermal conditions at 570 °C and 160 MPa and structurally characterized by single-crystal X-ray diffraction. The valence state of uranium was established by UV-vis and U 4f X-ray photoelectron spectroscopy. The powder sample has a second-harmonic-generation signal, confirming the abse...

The mixed-valence uranium(V,VI) oxyhydroxide Na5[U5O16(OH)2] is prepared via reduction of UO22+ under hydrothermal conditions using UO3, NaOH, Na2MoO4 (mineralizer), and Zn as reductant (autoclave, gold ampoule, 570 °C and 150 MPa, 2 d, 50% yield).

The title compound is hydrothermally synthesized from an aqueous mixture of UO3, NaOH, NaF, Na2HPO4, and Na2SiO3 in a molar ratio of Na:F:U:P:Si = 39:5:1:2:10 (autoclave, 160 MPa, 585 °C, 2 d, 71% yield).

An unusaul mixed-valence uranium(V,VI) oxyhydroxide, Na5[U5O16(OH)2], was synthesized via reduction of UO2(2+) with zinc under hydrothermal conditions at 570 °C and 150 MPa. Its structure consists of extended sheets of edge-sharing U(VI) pentagonal bipyramids and U(V) square bipyramids. The overall anion topology is the same as that of the uranyl m...

Three-layered zinc phosphites containing single monoamine molecules with different roles have been synthesized using hydro(solvo)thermal methods and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and infrared spectroscopy. Compound 1, (C8H17NH3)4Zn3(HPO3)5·3H2O, consists of 20-ring layer structures sandwiched by wate...

This is the first study on developing six alkali transition metal phosphites as potential candidates of cathode materials grown from molten boric acid, a simple, low energy costing method compared with conventional solid-state reactions. Li2[Mn(HPO3)2] (1) and Li[V(HPO3)2] (2) are featured with high theoretical capacitance values up to 117 and 123...

Crystals of the new title compound are synthesized from UO3, Eu2O3, and GeO2 using a mixture of KF and MoO3 as flux (Pt crucible, 950 °C, 48 h).

A salt-inclusion mixed-valence uranium(V,VI) silicate, [Na9F2][(U(V)O2)(U(VI)O2)2(Si2O7)2], was synthesized under hydrothermal conditions at 585 °C and 160 MPa and structurally characterized by powder and single-crystal X-ray diffraction (XRD). The valence states of uranium were established by U 4f X-ray photoelectron spectroscopy (XPS). The struct...

Crystals of a uranyl-europium germanate, K4[(UO2)Eu2(Ge2O7)2], have been grown at high temperature from a KF-MoO3 flux and structurally characterized by single-crystal X-ray diffraction. The structure contains PaCl5-type chains formed of edge-sharing EuO7 pentagonal bipyramids that are connected by digermanate groups such that layers of europium ge...

Two mixed-metal uranium compounds, [Cu(4,4′-bpy)(UO2)0.5(HPO4)(H2PO4)]·H2O (1) and [Cu(4,4′-bpy)(UO2)0.5(HAsO4)(H2AsO4)]·1.5H2O (2) have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction, fluorescence spectroscopy, and magnetic susceptibility. They are the first examples of mixed-metal...

Three new benzothieno[3,2-b]thiophene (BTT; 1) derivatives, which were end-functionalized with phenyl (BTT-P; 2), benzothiophenyl (BTT-BT; 3), and benzothieno[3,2-b]thiophenyl groups (BBTT; 4; dimer of 1), were synthesized and characterized in organic thin-film transistors (OTFTs). A new and improved synthetic method for BTTs was developed, which e...

The development of zeolite-like structures with extra-large pores (>12-membered rings, 12R) has been sporadic and is currently at 30R. In general, templating via molecules leads to crystalline frameworks, whereas the use of organized assemblies that permit much larger pores produces noncrystalline frameworks. Synthetic methods that generate crystal...

We have studied the spectroscopy of luminescent crystals containing rare earth elements such as KEuGe$_2$O$_6$, Cs$_3$EuSi$_6$O$_{15}$,, 5743 (2005).} K$_4$[(UO$_2$)Eu$_2$(Ge$_2$O$_7$)$_2$], and R$_2$(C$_8$H$_{10}$O$_4$)$_3$ (R= Y, Tb, or Eu). The emission and excitation spectra of these compounds were recorded at ambient temperature. These spectra...

Title compound (III) is characterized by single crystal XRD, solid state 19F NMR, and IR spectroscopy.

A new zinc germanate incorporating a tetradentate amine ligand has been synthesized by the solvothermal method and structurally characterized by single-crystal X-ray diffraction, solid-state (19)F NMR spectroscopy, thermal analysis, and IR spectroscopy. Its structure contains close-packed hollow columns with an 18-membered window, each of which con...

A new mixed-valence uranium germanate and the silicate analogue have been synthesized under hydrothermal conditions at 600 °C and 165 MPa. Their crystal structures contain infinite -U(V)-O-U(IV/V)-O-U(IV/V)-O-U(V)- chains that are connected by Ge(2)O(7) or Si(2)O(7) groups to form a 3D framework with six-ring channels where the Cs(+) cations are lo...

The title compound is hydrothermally synthesized from a mixture of UO3, CsF, CsI, CsCl, Al, GeO2, and H2O (Au ampule, autoclave, 160 MPa, 585 °C, 2 d, 72% yield).

A pentavalent uranium germanate, Cs(3)UGe(7)O(18), was synthesized under high-temperature, high-pressure hydrothermal conditions at 585 °C and 160 MPa and structurally characterized by single-crystal X-ray diffraction and infrared spectroscopy. The valence state of uranium was confirmed by X-ray photoelectron spectroscopy and electron paramagnetic...

Electrical and magnetic measurements have been carried out for the rare earth disordered superconducting copper oxide systems (Y1−xYbx)Ba2Cu3O7 (substitution with large rare earth mass difference) and (Sm1−xYbx)Ba2Cu3O7 (substitution with large rare earth ionic size difference). Effect of compositional variation upon room temperature electrical res...

The title compound is synthesized from a mixture of CsF, CsI, UO3, Al, and GeO2 in (gold ampule, autoclave, 160 MPa, 585 °C, 2 d).

A new uranium(VI) silicate, Cs(2)UO(2)Si(10)O(22), has been synthesized by a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction, luminescence, and solid state NMR spectroscopy. It crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 12.2506(4) Å, b = 8.0518(3) Å, c = 23.3796(8)...

A very rare tetravalent uranium germanate has been synthesized under hydrothermal conditions at 585 °C and 160 MPa. Its structure contains layers of single-ring Ge(3)O(9)(6-) germanate anions that are connected by UO(6) octahedra and dimers of edge-sharing GeO(5) trigonal bipyramids to form a three-dimensional framework with intersecting 6- and 7-r...

A very rare organically templated niobium germanate was synthesized and structurally characterized by single-crystal X-ray diffraction. The crystal shows an intense second harmonic generation signal. It is the first example of the synthesis of organically templated metal germanate using an ionic liquid as a solvent.

The title compound is synthesized along with Cs2UO2Si4O10 by hydrothermal reaction of UO3, CsF, and SiO2 using Al as a reducing agent (Cs:U:Si:Al = 50:1:6:0.6, H2O, Au ampule, autoclave, 600 °C, 2 d, 49% yield).

A uranium(IV) silicate has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure consists of unbranched dreier single layers with the composition [Si(2)O(5)] that are connected by UO(6) octahedra to form a 3D framework with 7-ring channels where the Cs(+) cations are located. Each UO(6) octahedron spans four...

A mixed-valence uranium(IV,VI) germanate has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure contains discrete U(IV)O(6) octahedra and U(VI)O(6) tetragonal bipyramids, which are connected by three-membered single-ring Ge(3)O(9)(6-) anions to form a three-dimensional framework with 9-ring channels. The U...

Complexes [Cu(SPh)(2)](-), [Cu(SPh)I](-) and K[Cu(SPh)(2)(Ph)](+) were observed by in situ electrospray ionization mass spectrometry (ESI-MS) analysis of the copper(i)-catalyzed C-S coupling reaction under catalytic reaction conditions indicating that they are intermediates in the reaction. A catalytic cycle was proposed based on these observations...

A new uranyl silicate, K6 (UO2)3Si8O22, was synthesized by a flux method and characterized by single-crystal X-ray diffraction, solid-state NMR, and photoluminescence spectroscopy. The 3D framework structure contains UO6 tetragonal bipyramids and a new type of (Si8O22)12- unit. K6 (UO2)3Si8O22, C2/m (No.12), a=1.24092 (9) nm, b=1.45678 (8) nm, c=0....

Colorless thin-plate crystals of the β-form (II) are synthesized as shown.

Two cobalt-containing analogues of the mineral alluaudite, NaCo3(XO4)(HXO4)2 (X = P, As), have been synthesized by hydrothermal methods and characterized by single-crystal X-ray diffraction. Crystal data: NaCo3(PO4)(HPO4)2, monoclinic, C2/c, a = 11.865(2) Å, b = 12.137(2) Å, c = 6.512(1) Å, β = 114.12(1)° V = 855.9(2) Å3, Z = 4, R = 0.0373; NaCo3(A...

Two new polymorphs, β- and γ-In(2)Ge(6)O(15)(NH(2)CH(2)CH(2)NH(2))(2), have been synthesized under solvothermal conditions using 2-methylpentamethylenediamine as a solvent and structurally characterized by single-crystal X-ray diffraction. Both structures contain single layers with the composition [Ge(6)O(15)] that are connected by In(2)O(6)N(4) oc...

Two piperazine-templated iron phosphates, (C4H12N2)[Fe4(OH) 2(HPO4)5] (1) and (C4H11N22)-0.5 [Fe3(HPO4)2(PO4)(H2O)] (2), have been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction, Mössbauer spectroscopy, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic space group C2/m (no. 12...

Black lamellar crystals of the title compound, which contains three unique uranium sites for U4+, U5+, and U5+/U6+ ions, are hydrothermally prepared from an aqueous mixture of UO3, SiO2, NaOH, and CsF in the molar ratio Na/Cs/U/Si = 10:5:0.5:6 (autoclave, 170 MPa, 600 °C, 2 d, 23% yield).

Colorless block crystals of compounds (III) are solvothermally prepared and their structures are determined by single crystal XRD.

Two zinc germanates incorporating neutral organic amine bridging ligands, Zn2Ge4O10(NH2CH2CH2CH2NH2) and ZnGe2O5(NH2CH2CH2NH2), have been synthesized under solvothermal conditions by using the amines as solvents. Their 3D framework structures are characterized by infinite chains formed of edge-sharing ZnO4N trigonal bipyramids and unbranched vierer...

Four new organically templated layered vanadyl(IV) phosphates, (Hcha)VOPO(4) x 0.5 H(2)O (cha = cyclohexylamine) (1), (Hchpa)VOPO(4) x 0.5 H(2)O (chpa = cycloheptylamine) (2), (Hcha)(0.5)(Hchpa)(0.5)VOPO(4) x 0.5 H(2)O (3), and (H(2)aepip)[(VOPO(4))(2)(H(2)O)] x H(2)O (aepip = N-(2-aminoethyl)piperazine) (4), have been synthesized under mild hydrot...

For U′r eyes only: A mixed-valence uranium silicate containing three different valence states of uranium has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure contains uranium silicate sheets with uranophane anion topology that are connected by UO6 octahedra to form a 2D layered structure with Na+ ions wi...

The mixed-valence iron phosphate NH4Fe2(PO4)2, which was synthesized by the high-temperature, high-pressure hydrothermal method, crystallizes in the monoclinic space group C2/c with a = 20.0066(1) Å, b = 14.8319(2) Å, c = 9.9899(1) Å, β = 119.278(1)°. and Z = 16. Its compact structure consists of chains of edge-sharing FeIIO6, octahedra and chains...

A new phosphate K2(VO)2P3O9(OH) 3·1.125H2O has been synthesized hydrothermally in a sealed quartz glass tube under autogeneous pressure by slowly cooling from 450°C a mixture of K4V2O7, V2O3, and 7.25 M H3PO4 and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The title compound crystallizes in the triclinic space...

The new phosphate Ca2V(PO4)(HPO4)2·H 2O and the dehydrated compound Ca2V(PO4)(P2O7) have been synthesized hydrothermally at 230 and 450°C, respectively, and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. Crystal data: Ca2V(PO4)(HPO4)2·H 2O, monoclinic, C2/c, a = 7.531 (2) Å, b = 15.522 (4) Å, c = 9.149 (2) Å, β =...

Figure Presented For U'r eyes only: A mixed-valence uranium silicate containing three different valence states of uranium has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure contains uranium silicate sheets with uranophane anion topology that are connected by UO6 octahedra to form a 2D layered structure...

Diphosphates of the stoichiometry AM3(P2O7)2 (A = alkaline-earth metals; M = Fe, Co, Ni) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Crystal data: CaNi3(P2O7)2, monoclinic, P21/c, a = 7.330(3) Å, b = 7.589(3) Å, c = 9.400(3) Å, β = 111.90(3)°, V = 485.1(3) Å3, Z = 2, and R = 0.026; CaCo3(P2O7)2, as abov...

Fifteen isostructural rare earth metal squarates incorporating ethylene glycol ligand with the formula RE(C(4)O(4))(1.5)(C(2)H(6)O(2)) (RE = Y, La-Nd, Sm-Lu) have been synthesized under hydrothermal conditions and structurally characterized by single-crystal and powder X-ray diffraction, (13)C CPMAS NMR, absorption spectroscopy, and magnetic suscep...