Published Papers - HASHIMOTO Masato

Control over the preference for binding sites of polyoxometalates to silver ethynide clusters by surface charge modification

Sho Tamari, Kosuke Ono, Masato Hashimoto, Tomoji Ozeki

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  44 ( 44 ) 19056 - 19058   2015  [Refereed]

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A polyoxometalate-silver ethynide composite cluster, [Ag-42(CO3)-{ C = CC(CH3)(3)}(27)(alpha-A-SiW9Nb3O40)(2)](-) (1), demonstrates that we can select the binding site of a polyoxometalate to the silver alkynide cluster by tuning the surface charge of the precursor polyoxometalate. Multidimensional and multinuclear NMR spectra revealed that 1 maintains its precise atomic connectivity in the solution.

DOI

Synthesis, structure and spectroscopic analyses of aquachloridooxidodiperoxidomolybdate(VI)

Masa-aki Saito, Masato Hashimoto

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  43 ( 2 ) 402 - 405   2014  [Refereed]

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A novel aquachloridooxidodiperoxidomolybdate(VI), [MoClO(O-2)(2)(OH2)](-), was crystallised as tetraethylammonium and triethylmethylammonium salts from strongly acidic aqueous solutions, and was structurally analysed by single crystal X-ray diffraction and NMR spectroscopy. The aqueous behaviour of the present anion observed by O-17 NMR agrees with that reported in a previous speciation study.

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Calcium and strontium salts of (glycinato-κ2 N,O)oxidobis(peroxido-κ2O,O′)vanadate(V) tetrahydrate

Takeshi Higuchi, Ayana Uchida, Masato Hashimoto

Acta Crystallographica Section C: Crystal Structure Communications   69 ( 12 ) 1494 - 1497   2013.12  [Refereed]

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The title salts calcium (glycinato-κ2 N,O) oxidobis(peroxido-κ2 O,O′)vanadate(V) tetrahydrate, Ca[VO(O2)2(NH2CH2COO)] ·4H2O, and strontium (glycinato-κ2 N,O)oxidobis(peroxido-κ2 O,O′)vanadate(V) tetrahydrate, Sr[VO(O2)2(NH2CH2COO)] ·4H2O, crystallized at pH ca 7.4 with similar lattice parameters. The glycinate anion acts as a bidentate N,O-chelating ligand, and the V atom has a pentagonal bipyramidal geometry, with two η2- peroxo groups and the glycinate N atom in the equatorial plane, and one terminal oxo and a glycinate O atom at the axial positions. The H atoms of three of the four water molecules in the strontium salt exhibited disorder over three positions for each molecule. © 2013 International Union of Crystallography.

DOI

Dipotassium Diaquadiphosphatooctaperoxotetramolybdate, [K-2(P2O7){MoO(O-2)(2)}(2){MoO(O-2)(2)(OH2)}(2)](2-) - a One-Dimensional Double Chain Array of Polyanions Linked by Potassium Cations

Koji Aoki, Keisuke Iwata, Takahiro Iwata, Masato Hashimoto

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY ( WILEY-V C H VERLAG GMBH )  ( 10-11 ) 1808 - 1814   2013.04  [Refereed]

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A dipotassium diaquadiphosphatooctaperoxotetramolybdate, [K2(P2O7){MoO(O2)2}2{MoO(O2)2(OH2)}2]2, was crystallised as a tetramethylammonium salt and its structure was determined by single-crystal X-ray diffraction. The diaquadiphosphatooctaperoxotetramolybdate moiety (POPMo4) consists of four molybdenum decahedra and one 4-diphosphate group. All Mo atoms bear two peroxo groups at their equatorial positions. Two of the four Mo atoms are also coordinated by a water molecule. The four molybdenum decahedra are separated and linked by the diphosphate group. The POPMo4 moieties are linked by potassium atoms to form an infinite anionic 1D double chain. The chains are connected by hydrogen bonds to water of crystallisation molecules to form a 2D network. POPMo4 or its precursor gives a 31P NMR signal at = 7.3 ppm in the reaction solution and is stable at low pH and a high Mo/diphosphate molar ratio.

DOI

Potassium, rubidium and ammonium salts of -(formato-2O:O)--oxido-bis[oxidobis(peroxido-2O,O)molybdate(VI)]

Masaki Takehara, Masato Hashimoto

ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS ( WILEY-BLACKWELL )  69   37 - +   2013.01  [Refereed]

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The unit-cell parameters of the three title salts, namely, tripotassium, K3[Mo2(CHO2)O3(O2)4], trirubidium, Rb3[Mo2(CHO2)O3(O2)4], and triammonium -(formato-2O:O)--oxido-bis[oxidobis(peroxido-2O,O)molybdate(VI)], (NH4)3[Mo2(CHO2)O3(O2)4], which were all crystallized at pH 3, are quite similar, but the potassium and rubidium salt structures are noncentrosymmetric, whereas that of the ammonium salt is centrosymmetric. Formate acts as an O:O-bridging ligand in the complex anion and is bound to a -oxido-bis(oxidodiperoxidomolybdate) unit.

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Bis(trimethylphenylammonium) μ-oxalato-bis[oxidodiperoxidomolybdate(VI)]

Ayaka Oba, Masato Hashimoto

Acta Crystallographica Section E: Structure Reports Online   68 ( 12 ) m1467   2012.12  [Refereed]

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A trimethylphenylammonium salt of a dinuclear μ-oxalate complex of diperoxidomonomolybdate units, (C9H14N)2[Mo2(C2O4)(O2)4O2], was obtained from an acidic aqueous solution
the dianion is located about a centre of inversion. Each Mo atom bears two peroxide groups together with one O atom from the oxalate group in its equatorial positions and one terminal O atom as well as another O atom from the oxalate in axial positions. The oxalate group acts as a tetradentate bridging ligand and bridges between the diperoxidomolybdate units.

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Role of p(Z)-pi(Ar/Nap) conjugation in structures of 1-(arylchalcogena)-naphthalenes for Z = Te versus Se, S and O: experimental and theoretical investigations

Takahito Nakai, Mitsuhiro Nishino, Satoko Hayashi, Masato Hashimoto, Waro Nakanishi

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  41 ( 25 ) 7485 - 7497   2012  [Refereed]

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Magnitudes of the p(Z)-pi(Ar/Nap) conjugation were evaluated for 1-(arylchalcogena)naphthalenes (1-(ArZ)Nap, 1-(p-YC(6)H(4)Z)C10H7; 1 (Z = Te), 2 (Se), 3 (S) and 4 (O)). Structures of 1 were determined by X-ray analysis for Y = NMe2 (b), OMe (c) and CN (i). For 1b and 1c that have electron donating Y, the Z-C-Ar bond is located on the naphthyl plane with Z-C-Nap being perpendicular to the aryl plane, which we define as (B: pd). On the other hand, the structure of 1i with electron donating Y is (A: pl), of which Z-C-Ar is placed almost perpendicular to the naphthyl plane with Z-C-Nap being located on the aryl plane. Each structure of 1a (Y = H), 1b, 1c, 1d (Me), 1e (F), 1f (Cl), 1g (Br), 1h (COOEt), 1i and 1j (NO2) was determined by NMR in chloroform-d. Structures of 1 in the solutions are (B: pd) for b, c and e that have electron donating Y, (A: pl) for f-j with electron accepting Y, and in equilibrium between (B: pd) and (A: pl) for a and d of which Yare rather neutral. The results for 2-4 are very similar to those of 1 in solutions. Quantum chemical calculations were performed on 1-4 with Yof a, b' (NH2), d, f and j. Magnitudes of the p(Z)-pi(Ar/Nap) conjugation were well-evaluated by NBO (natural bond orbital) analysis. The values were 12.6 and 13.0 kcal mol(-1) for the typical forms of (A: pl) and (B: pd) of 1a, respectively, resulting in a much smaller energy difference between the two (0.4 kcal mol(-1)), which should correspond to the observed result. It is well-demonstrated that the p(Te)-p(Ar/Nap) conjugation operates effectively in 1, although the magnitudes increase in the order of Z = Te < Se < S < O. Thermal effect of the Gibbs free energies is shown to play an important role in the energy profiles of 1a-4a.

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A P-31-NMR study of the H+-MoO42--(HP)O-3(2-)-HPO42--(C6H5P)O-3(2-)-(CH3P)O-3(2-) system at low Mo-tot/P-tot ratio - Formation of mixed-hetero X2M5-type polyanions

Masato Hashimoto, Ingegaerd Andersson, Lage Pettersson

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  ( 17 ) 3321 - 3327   2009  [Refereed]

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Formation of X2M5-type heteropolyanions in the aqueous mixed-hetero H+-MoO42--(HP)O-3(2-)-HPO42--(C6H5P)O-3(2-)- (C6H3P)O-3(2-) system has been studied by P-31-NMR at [Mo](tot)/[P-all](tot) = 1.5 at 298(1) K in 0.600 M Na(Cl) ionic medium. The -log[H+] range 1.4-6.2 has been covered. The pK(a) values of methylphosphonate were determined from P-31-NMR chemical shift data in the range of 0 < -log[H+] < 13.2 as H(CH3P)O-3(-) 7.30 and H-2(CH3P)O-3 2.05. All four-component H+-MoO42--P1-P2 subsystems (P1 and P2 are two of the four phosphorus-containing components), except H+-MoO(4)2(-)-(HP)O-3(2-)-HPO42-, which has been studied previously, were examined instead of the full six-component system in order to simplify the evaluation of the NMR spectra. The concentrations were adjusted to [Mo](tot) = 60 mM and [P1](tot) = [P2](tot) = 20 mM in the measurements. All conceivable P2M5 and (P1)(P2)M5 heteropolyanions were identified. The following novel X2M5-type polyanions were found and their formation constants are given in logarithmic values with 36 in parentheses: (CH3P)(2)Mo5O214- 69.68(7), (HP)(C6HSP)Mo5O214- 67.09(4), (C6H5P)PMo5O225- 63.23(5), H(C6H5P)PMo5O224- 68.11(4), (HP)(CH3P)Mo5O214-- 67.85(4), (CH3P)PMo5O225- 64.14(7), H(CH3P)Mo5O224- 68.89(4) and (C6H5P)(CH3P)Mo5O214- 69.18(4). The equilibrium conditions are illustrated in distribution diagrams. Phosphite proved to bind more weakly in X2M5-type polyoxometallates than phosphate or phosphonates, which are almost equally favoured in complexation.

DOI

Preparation and Characterization of an alpha-Wells-Dawson-Type [V2Mo18O62](6-) Complex

Sadayuki Himeno, Keishi Kawasaki, Masato Hashimoto

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN ( CHEMICAL SOC JAPAN )  81 ( 11 ) 1465 - 1471   2008.11  [Refereed]

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An orange-yellow vanadomolybdate complex was prepared by heating a 100 mM Mo-VI-20 mM V-V-0.45 M HCl-20% (v/v) CH3CN system at 70 degrees C for 24 h, being isolated as the tetrapropylammonium (Pr4N+) salt. The Pr4N+ salt crystallized in the orthorhombic space group P2(1)2(1)2; the lattice constants were a = 18.417(4), b = 20.869(5), c = 15.280(3) angstrom, V = 5873(2) angstrom(3), and Z = 2. The crystallographic study revealed that the structure consists of The alpha-Wells-Dawson-type [V2Mo18O62](6-) anion, in which vanadates serve as the central tetrahedra. alpha-[V2Mo18O62](6-) complex underwent a two-step one-electron reduction in CH3CN, and the presence of acid caused the one-electron waves to be converted into three two-electron waves. The formation conditions were elucidated by V-51 NMR measurements.

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An equilibrium analysis of the aqueous H+-MoO42--(HP)O-3(2-)-H+MoO42--(HP)O-3(2-)-(HPO)(4)(2-) and systems

Masato Hashimoto, Ingegaerd Andersson, Lage Pettersson

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  ( 1 ) 124 - 132   2007.01  [Refereed]

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The speciation in the phosphitomolybdate system, H+-MoO42--(HP)O-3(2-), has been determined from combined potentiometric and P-31 NMR measurements in 0.600 M Na(Cl) medium at 298(1) K. Potentiometric titration data were collected in the ranges 2.5 < -log[H+] < 6.2, 40.0 <= [Mo](tot) <= 240.0 mM, 10.0 <= [P](tot) <= 40.0 mM and l <= [Mo](tot)/[P](tot) <= 10. P-31 NMR data were collected in the same ranges with the exception that -log[H+] was decreased to 0.8. The pK(a) values of phosphite were determined by means of potentiometric (1.5 < -log[H+] < 8.6) and P-31 NMR chemical shift data (0.0 < -log[H+] < 12.0). The following log beta (3 sigma) values were deduced: H(HP)O-3(-), 6.09(2); H-2(HP)O-3, 7.23(4) (pK(a) = 1. 14). In the phosphitomolybdate system, the following complexes were found along with their formation constants ((HP) denotes phosphite): Mo-5(HP)(2)(4-), 65.31(4); Mo-6(HP)(2)(5-), 71.94(5); Mo-5(HP)(4-), 51.25(8); Mo-5(HP)(3-), 54.9(3); Mo-6(HP)(2-), 68.99(9); Mo-7(Hp)(5-), 71.25(3); Mo-7(HP)(4-), 74.2(2). Because hydrolysis and oxidation of phosphite to phosphate were observed by NMR, with a mixed-hetero species of low [Mo](tot)/[P](tot) ratio being detected, the four-component H+-MoO42-(HP)-O-3(2-)-HPO42- system was also studied in the same way over the range 0.8 < -log[H+] < 6.2 and [Mo](tot)/[P](tot) fixed at 1.5. The following mixed heteropolyanion species have been found (P denotes the phosphate group): Mo-5(HP)P5-, 62.27(6); Mo-5(HP)P4-, 66.76(4). The equilibrium speciation in the two systems are illustrated by distribution diagrams. In addition, the aqueous structures are proposed for all the species formed in the systems.

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Preparation, structure, and characterization of a novel diphosphoheptadecatungstate complex, [(P2O7)W17O51](4-)

S Himeno, T Katsuta, M Takamoto, M Hashimoto

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN ( CHEMICAL SOC JAPAN )  79 ( 1 ) 100 - 105   2006.01  [Refereed]

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A novel diphosphoheptadecatungstate complex, [(P2O7)W17O51](4-) was prepared from a 200 mM (M = mol dm(-3)) W(VI)-10 mM P2O74--0.6 M HCl-40% (v/v) CH3CN system, and characterized by IR, UV-vis, P-31 NMR, and W-183 NMR spectroscopy, and voltammetry. Single-crystal X-ray analysis was made on [(C2H5)(4)N](4)[(P2O7)W17O51]center dot CH3CN, which crystallized in the monoclinic space group P2(1)/n, with cell parameters a = 16.1877(8), b = 22.103(1), c = 21670(1) angstrom, beta = 90.847(1)degrees, V = 8110.3(7) angstrom(3), and Z = 4. The anion consists of a PW8O31 fragment derived from a beta-Keggin-type [PW12O40](3-) structure, and two PW8O31 units are linked by five oxygen atoms and a WO5 square pyramid. The [(P2O7)W17O51](4-) anion exhibited a four-step reversible one-electron redox wave in CH3CN, and a three-step two-electron redox wave resulted in the presence of acid. This is the first example of an electrochemically-active diphosphotungstate complex.

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First transition metal complex of 1,8-bis(dimethylamino)naphthalene (proton sponge)

T Yamasaki, N Ozaki, Y Saika, K Ohta, K Goboh, F Nakamura, M Hashimoto, S Okeya

CHEMISTRY LETTERS ( CHEMICAL SOC JAPAN )  33 ( 7 ) 928 - 929   2004.07  [Refereed]

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First transition metal complexes of 1,8-bis(dimethyl-amino)naphthalene (proton sponge), N,N'-chelated Pd(II) complexes, were prepared and the strong coordination ability of the proton sponge was demonstrated. The high transition energy for the coordination could be lowered by the existence of the intermediate charge-transfer complex which was isolated.

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Preparation and characterization of an alpha-Keggin-type [SW12O40](2)-complex

S Himeno, M Takamoto, M Hoshiba, A Higuchi, M Hashimoto

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN ( CHEMICAL SOC JAPAN )  77 ( 3 ) 519 - 524   2004.03  [Refereed]

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A divanadium-substituted derivative of 12-tungstosulfate(VI), [S(V2W10)O-40](4-) was prepared as the tetrabutylammonium (n-Bu4N+) salt by heating a 50 nM (M = mol dm(-3)) W(VI)-20 mM V(V)-0.5 M H2SO4-50% (v/v) CH3CN system at 70 degreesC for 24 h. The [S(V2W10)O-40](4-) anion Was transformed spontaneously into a monovanadium-substituted derivative, [S(VW11)O-40](3-) in a 70% (v/v) CH3CN-1.0 M HCl system at 70 degreesC. Oil the other hand, [SW12O40](2-) was precipitated as the n-Bu4N+ salt upon heating a 95% (v/v) CH3CN-0.5 M HCl system containing [S(V2W10)O-40](4-). The single-crystal X-ray structural analysis revealed that the structure consisted of an alpha-Keggin-type [SW12O40](2-) anion. The [SW12O40](2-) anion was characterized by IR and UV-vis spectroscopy, and voltammetry.

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Synthesis and Crystal Structure of Cs₂(CN₃H₆)₃[(C₂H₅)₂NH₂][W₇O₂₂(O₂)₂].3H₂O

Hiroyuki Suzuki, Masato Hashimoto, Seichi Okeya

Eur. J. Inorg. Chem.     2632 - 2634   2004  [Refereed]

Synthesis and structural characterization of [HxCp*TiMo5O18]((3-x)-) (x=0, 1, 2); new insights into protonation patterns in polyoxometalates

H Akashi, J Chen, H Hasegawa, M Hashimoto, T Hashimoto, T Sakuraba, A Yagasaki

POLYHEDRON ( PERGAMON-ELSEVIER SCIENCE LTD )  22 ( 20 ) 2847 - 2854   2003.09  [Refereed]

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Reaction Of [(n-C4H9)(4)N](2)[Mo2O7], Cp*TiCl3, and [(n-C4H9)(4)N]OH in CH3CN yields [(n-C4H9)(4)N](3)[Cp*TiMo5O18].CH3CN [a = 12.863(4) Angstrom b = 26.608(6) Angstrom, c = 24.534(4) Angstrom, beta = 103.88(2)degrees, Z = 4, space group P2(1)/c (no. 14)]. Similar reaction without [(n-C4H9)(4)N]OH yields monoprotonated complex [(n-C4H9)(4)N](2)[HCp*TiMo5O18], where, according to a single-crystal X-ray diffraction study [a = 19.9550(4) Angstrom, b = 25.5420(8) Angstrom, c = 11.8820(3) Angstrom, beta = 100.31(2)degrees, Z = 4, space group P2(1)/n (no. 14)], the anion is protonated at one of OMo2 doubly-bridging oxygens. Reaction of [(n-C4H9)(4)N](2)[HCp*TiMo5O18] with CCl3COOH in CHCl3 followed by crystallization from CH3CN/Et2O yields diprotonated [(n-C4H9)(4)N][H2Cp*TiMO5O18].1/4(C2H5)(2)O, which, according to a single-crystal X-ray diffraction study [a = 12.319(2) Angstrom, b = 16.105(3) Angstrom, c = 12.001(2) Angstrom, alpha = 110. 74(1)degrees, beta = 100.31(2)degrees, gamma = 82.777(5) Z = 2, space group P (1) over bar (no. 2)], contains hydrogen-bonded dimers of [H,,Cp*TiMo5O19](-) ions. The [Cp*TiMo5O18](3-) is basic enough to form stable organometallic adducts like [(eta-C8H12)Ir(Cp*TiMo5O18)](2-) and [(eta-C8H14)Rh(Cp*TiMo5O18)](2-). (C) 2003 Elsevier Ltd. All rights reserved.

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O-17 NMR study of aqueous peroxoisopolymolybdate equilibria at lower peroxide/Mo ratios

L Pettersson, Andersson, I, F Taube, Toth, I, M Hashimoto, OW Howarth

DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  ( 1 ) 146 - 152   2003  [Refereed]

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Aqueous peroxomolybdates have been studied using O-17 NMR together with equilibrium measurements and calculations, over a wide range of conditions. Ten peroxo species are identified, mostly in more than one state of protonation. Some are already known in the solid state, or from equilibrium analysis, but structural information is also obtained for MoO3 (HO2)(-) and the new or previously tentative species Mo2O5 (O-2)(2)(2-), HpMo7O23 (O-2)(2)(p-6) and HpMo7O23 (O-2)(p-6) (p = 0-2). Sites of protonation are identified, as are O-17 resonances from both bidentate and monodentate peroxide. Several oxygen exchange processes are also seen, including a probable dimer-tetramer exchange.

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A breathing ionic crystal displaying selective binding of small alcohols and nitriles: K-3[Cr3O(OOCH)(6)(H2O)(3)][alpha-SiW12O40]center dot 16H(2)O

S Uchida, M Hashimoto, N Mizuno

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION ( WILEY-V C H VERLAG GMBH )  41 ( 15 ) 2814 - +   2002  [Refereed]

[Ni(H₂O₆)]₂[Na(H₂O)₃]₂ V₁₀O₂₈・4H₂O

Tomoyuki Higami, Masato Hashimoto, Seichi Okeya

Acta Crystallogr. Sect. C   C58   i144 - i146   2002  [Refereed]

Characterisation of aqueous peroxomolybdate catalysts applicable to pulp bleaching

F Taube, M Hashimoto, Andersson, I, L Pettersson

JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS ( ROYAL SOC CHEMISTRY )  ( 6 ) 1002 - 1008   2002  [Refereed]

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The equilibrium speciation in the system p H++ q MoO42-+ rH(2)O(2) + sSO(4)(2-) reversible arrow(H+)(p) (MoO42-)(q) (H2O2)(r) (SO42-)s in 0.300 M Na-2 (SO4) medium at 25 degreesC has been determined from potentiometric titration data in the ranges 2.0 less than or equal topH less than or equal to5.5, 5.00 less than or equal to[Mo](tot)/mM less than or equal to80.00, 0 less than or equal to[H2O2](tot)/mM less than or equal to245 and 273.07 less than or equal to[SO42-](tot)/mM less than or equal to320.20. Species with the following compositions were found: MoX- (1,1,1,0), MoX (2,1,1,0), MoX2- (1,1,2,0), MoX2 (2,1,2,0), MoX2S2- (2,1,2,1), Mo2X42- (2,2,4,0), Mo7X6- (8,7,1,0), Mo7X5- (9,7,1,0), Mo7X4- (10,7,1,0) and Mo7X3- (11,7,1,0). The numbers in parentheses refer to the values of p, q, r and s in the formula above. The numbers and charges of molybdenum (Mo), peroxide (X) and sulfate (S) in each species are given in the abbreviated formula MoqXrSs(2q + 2s - p)-. The following formation constants with 3sigma were obtained; logbeta(1,1,1,0) = 8.53 +/- 0.03, log beta(2,1,1,0) = 11.22 +/- 0.04 (pK(a) = 2.69), log beta(1,1,2,0) = 11.61 +/- 0.03, log beta(2,1,2,0) = 13.77 (+/- 0.06) (pK(a) = 2.16), log beta(2,1,2,1) = 14.50 +/- 0.06, log beta(2,2,4,0) = 23.77 +/- 0.11, log beta(8,7,1,0) = 56.71 +/- 0.11, log beta(9,7,1,0) = 62.00 +/- 0.05 (pK(a) = 5.29), log beta(10,7,1,0) = 65.74 +/- 0.06 (pK(a) = 3.74), log beta(11,7,1,0) = 68.23 +/- 0.08 (pK(a) = 2.49). Most complexes have been verified by Mo-95 NMR, O-17 NMR, and the novel MoX2S2- complex also by FTIR spectroscopy.

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Origin of microporosity of ammonium dodecatungstophosphate unveiled by single crystal structure analysis

T Ito, M Hashimoto, S Uchida, N Mizuno

CHEMISTRY LETTERS ( CHEMICAL SOC JAPAN )  ( 12 ) 1272 - 1273   2001.12  [Refereed]

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The single crystals of ammonium dodecatungstophosphate were successfully synthesized and the structure was analyzed. The intrinsic crystal structure (cubic, Pn (3) over barm) had no cavity. It follows that the microporosity observed for the powdery sample originated from narrow spaces surrounded by the fine nanocrystallites.