Preparation,Crystal Structure and Vibrational Spectra of Ca2P2O6·2H2O and [Ca(H2O)3(H2P2O6)]·0.5(C12H24O6)·H2O

The calcium salts Ca₂P₂O₆ · 2H₂O ( 1 ) and [Ca(H₂O)₃(H₂P₂O₆)] · 0.5(C₁₂H₂₄O₆) · H₂O ( 2 ) were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pbca and compound 2 in the monoclinic space group P2₁/n. The crystal structure of compound 1 consists of chains of edge‐sharing [CaO₇] polyhedra linked by hypodiphosphate(IV) anions to form a three‐dimensional network. The crystal structure of compound 2 consists of alternated layers of crown ether and water molecules and respective ionic units. Within the layers of ionic units the Ca²⁺ cations are octahedrally coordinated by three monodentate dihydrogenhypodiphosphate(IV) anions and three water molecules. The IR/Raman spectra of the title compounds were recorded and interpreted, especially with respect to the [P₂O₆]^4– and [H₂P₂O₆]^2– groups. The phase purity of 2 was verified by powder diffraction measurements.     

VF(C4O4)(H2O)2: a new layer type of diaqua­vanadium(III) fluoride squarate

Single crystals of the title compound, poly[diaqua‐μ‐fluoro‐μ‐squarato‐vanadium(III)], [V(C₄O₄)F(H₂O)₂]_n, have been prepared hydro­thermally at 423 K. This compound is shown to have a layer‐type structure. The V and F atoms are localized on the symmetry centers 2a and 2d, respectively, of the monoclinic system (space group P2₁/n) and they form infinite chains which are bridged by the squarate group acting as a bidentate ligand in a trans position. Two water mol­ecules complete the octa­hedral coordination of vanadium(III). The three‐dimensionality is ensured by a strong O—H⋯O hydrogen bond.     

KCo(H2O)2BP2O8·0.48H2O and K0.17Ca0.42Co(H2O)2BP2O8·H2O: two cobalt borophosphates with helical ribbons and disordered (K,Ca)/H2O schemes

The two title compounds, potassium diaquacobalt(II) borodiphosphate 0.48‐hydrate and potassium–calcium(0.172/0.418) diaquacobalt(II) borodiphosphate monohydrate, were synthesized hydrothermally. They are new members of the borophosphate family characterized by _∞[BP₂O₈]³⁻ helices running along [001] and constructed of boron (Wyckoff position 6b, twofold axis) and phosphorus tetrahedra. The [CoBP₂O₈]⁻ anionic frameworks in the two materials are structurally similar and result from a connection in the ab plane between the CoO₄(H₂O)₂ coordination octahedra (6b position) and the helical ribbons. Nevertheless, the two structures differ in the disorder schemes of the K,Ca and H₂O species. The alkali cations in the structure of the pure potassium compound are disordered over three independent positions, one of them located on a 6b site. Its framework is characterized by double occupation of the tunnels by water molecules located on twofold rotation axes (6b) and a fraction of alkali cations; its cell parameters, compared with those for the mixed K,Ca compound, show abnormal changes, presumably due to the disorder. For the K,Ca compound, the K and Ca cations are on twofold axes (6b) and the channels are occupied only by disordered solvent water molecules. This shows that it is possible, due to the flexibility of the helices, to replace the alkali and alkaline earth cations while retaining the crystal framework.     

Synthesis,Crystal Structure and Characterization of a new Protonated Magnesium Borophosphate: (H3O)Mg(H2O)2[BP2O8]·H2O

A new protonated borophosphate (H₃O)Mg(H₂O)₂[BP₂O₈]·H₂O ( 1 ) was synthesized under mild hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, FTIR spectroscopy and TG‐DTA. The compound crystallizes in the hexagonal system, space group P6(1)22 (No 178), a = 9.4462(7) Å, c = 15.759(2) Å, V = 1217.8(2) Å³, and Z = 6. There exist infinite helical $^1_\infty$ {[BP₂O₈]^3–} ribbons built up from corner‐sharing PO₄ and BO₄ tetrahedra, which are connected by MgO₄(H₂O)₂ leading to an infinite three‐dimensional open‐framework. The H₃O⁺ ions are located at the free thread of the helical ribbons, whereas crystallized water occupy the channels of the helical ribbons. The dehydration of the compound occurs at a higher temperature which is presumably due to the anisotropic hydrogen bonds in the crystal structure. The luminescent properties of the compound were studied.     

Preparation,Crystal Structure,Vibrational Spectra,and Thermal Behavior of Tl2H2P2O6 and Tl4P2O6

The new thallium(I) salts, Tl₂H₂P₂O₆ ( 1 ) and Tl₄P₂O₆ ( 2 ), were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the monoclinic space group P2₁/c and compound 2 in the orthorhombic space group Pbca. Both structures feature channels occupied by the lone electron pairs of Tl⁺ cations. Furthermore, those are built up by discrete [H₂P₂O₆]^2– for compound 1 and [P₂O₆]^4– units for 2 in staggered conformation for the P₂O₆ skeleton and the thallium cations. In Tl₂H₂P₂O₆ ( 1 ) the hydrogen atoms of the [H₂P₂O₆]^2– ion are in a “trans‐trans” conformation. The O ··· H–O hydrogen bonds between the [H₂P₂O₆]^2– groups consolidate the structure 1 into a three‐dimensional network. FT‐IR/FIR and FT‐Raman spectra of the crystalline title compounds were recorded and a complete assignment for the P₂O₆^4– modes is proposed. The phase purity of 1 was verified by powder diffraction measurements.     

Non-Isothermal Decomposion Kinetics of Supermolecule Compound [Eu(C_(10)H_9N_2O_4)(C_(10)H_8N_2O_4)(H_2O)_3]_2·phen·4H_2O

Europium(Ⅲ) compound with 2-oxopropionic acid salicyloyl hydrazone (C_(10)H_(10)N_2O_4,H_3L) and 1,10-phenan-throline (C_(12)H_8N_2,phen) has been prepared.A yellow prismatic crystal of the compound was obtained,and themolecule crystallized in the triclinic space group P-1.There are two 9-coordinated complex molecules in everystructure unit,where every Eu atom is coordinated by three water molecules and two tridentate C_(10)H_(10)N_2O_4 ligands,forming two stable pentacycles.The coordination polyhedron around Eu~(3+) was described as a single cap squareantiprism.In the crystal cell,there are one free 1,10-phenanthroline and four water molecules.The thermaldecomposition of the compound and its kinetics were studied by non-isothermal thermogravimetry.The Kissinger'smethod and Ozawa's method were used to calculate the activation energy value of the first-step decomposition.Thestages of the decompositions were identified by TG-DTG-DSC curve.The non-isothermal kinetic data were ana-lyzed by means of integral and differential methods.The possible reaction mechanism and the kinetic equationswere investigated by comparing the kinetic parameters.     

Preparation,Crystal Structure,Vibrational Spectra,and Thermal Behavior of Rb2H2P2O6·2H2O

Single crystals of Rb₂H₂P₂O₆ · 2H₂O could be obtained from aqueous solutions of hypodiphosphoric acid and rubidium carbonate. Its crystal structure was determined by X‐ray diffraction and it crystallizes in the monoclinic space group P2₁/c with Z = 4. The salt‐like title compound consists of [H₂P₂O₆]^2– units in staggered P₂O₆‐skeleton conformation, Rb⁺ cations, and H₂O molecules, held together by intermolecular hydrogen bonds of the type O ··· O. The vibrational spectra (IR/FIR and Raman) of the rubidium salt were recorded and an assignment of the vibrational modes is proposed based on the point group C_2h for the P₂O₆‐skeleton of the anion. The thermal behavior of Rb₂H₂P₂O₆ · 2H₂O is dominated by a complex TG decay indicating a simultaneous H₂O delivery coupled with a disproportionation of [H₂P₂O₆]^2–, what is also supported by Raman spectra of heated samples.     

Synthesis,crystal structure and magnetic properties of Co(NIT4Py)(H2PDA)(H2O)3

A Co(II)-pyridyl substituted nitronyl nitroxide complex Co(NIT4Py)(H₂PDA)(H₂O)₃ has been synthesized and structurally characterized (NIT4Py: 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and H₂PDA: 2,5-pyridine dicarboxylic acid). The compound is in the monoclinic space group P2(1)/c, a = 16.892(5) Å, b = 7.371(2) Å, c = 18.856(5) Å, β = 108.770(5)°, V = 2223.0(11) ų, Z = 4 and F(000) = 1064. The cobalt is in a distorted octahedral environment with one nitrogen from NIT4Py, one oxygen atom from H₂PDA, two oxygens from two water molecules in the basal plane and one nitrogen from H₂PDA and one water in the axial positions. The molecules are connected as a layered structure by intermolecular hydrogen bond interactions. Variable temperature magnetic susceptibility measurements reveal the occurrence of weak antiferromagnetic interactions in the compound.     

Synthesis,Structural Characterization and Thermal Stability of [Mn(3‐bpd)2(NCS)2(H2O)2]·2H2O (1) and {[Mn(bpe)(NCS)2(H2O)2]·(3‐bpd)·(bpe)·H2O}n (2) from One‐Pot Crystallization

Two supramolecular architectures, [Mn(3‐bpd)₂(NCS)₂(H₂O)₂]·2H₂O ( 1 ) and {[Mn(bpe)(NCS)₂(H₂O)₂]·(3‐bpd)·(bpe)·H₂O}_n ( 2 ) [bpe = 1,2‐bis(4‐pyridyl)ethylene and 3‐bpd = 1,4‐bis(3‐pyridyl)‐2,3‐diaza‐1,3‐butadiene] have been synthesized and characterized by spectroscopic, elemental and single crystal X‐ray diffraction analyses. Compound 1 crystallizes in the monoclinic system, space group P2₁/c, with chemical formula C₂₆H₂₈Mn N₁₀O₄S₂, a = 9.1360(6), b = 9.7490(6), c = 17.776(1) Å, β = 93.212(1)°, and Z = 2 while compound 2 crystallizes in the orthorhombic system, space group P2₁2₁2₁, with chemical formula C₃₈H₃₆Mn₁N₁₀O₃S₂, a = 14.1902(6), b = 15.4569(7), c = 18.2838(8) Å, α = β = γ = 90°, and Z = 4. Structural determination reveals that the coordination geometry at Mn(II) in compound 1 or 2 is a distorted octahedral which consists of two nitrogen donors of two NCS^?ligands, two oxygen donors of two water molecules, and two nitrogen donors of two 3‐bpd ligands for 1 and two dpe ligands for 2 , respectively. The two 3‐bpd ligands in 1 adopt a monodentate binding mode and the dpe in 2 adopts a bismonodentate bridging mode to connect the Mn(II) ions forming a 1D chain‐like coordination polymer. Both the π‐π stacking interactions between the coordinated and the free pyridyl‐based ligands and intermolecular hydrogen bonds among the coordinated and the crystallized water molecules and the free pyridyl‐based ligands play an important role in construction of these 3D supramolecular architectures.     

Neptunium(V) Perrhenate Complex with 1,10-Phenanthroline [(NpO2)(ReO4)(Phen)(H2O)2]: Crystal Structure and Absorption Spectra

Neptunium(V) perrhenate complex [(NpO₂)(ReO₄)(Phen)(H₂O)₂] was synthesized with 1,10-phenanthroline as a ligand. Its composition and structure were determined by X-ray diffraction analysis. The coordination polyhedron of the Np atom is a pentagonal bipyramid. The nearest surrounding of the neptunoyl ion includes the oxygen atom of the ReO₄ anion, two nitrogen atoms of phenanthroline, and the oxygen atoms of two water molecules. The crystals of the compound are monoclinic. The main crystallographic parameters are the following: space group P2₁/c, unit cell parameters a = 7.288(1) Å, b = 10.513(2) Å, c = 20.936(4) Å, = 96.939(5)°, Z = 4, V = 1592.2(5) ų. Absorption spectra of the compound in visible and IR regions are reported.     

Synthesis and Characterization of the New Lacunar Zincophosphate [C6H10N2][ZnP2O8H2]·0.6H2O

The new zincophosphate of chemical formula [C₆H₁₀N₂][ZnP₂O₈H₂] · 0.6H₂O was hydrothermally synthesized with p‐phenylenediamine as structure‐directing agent. The title compound crystallizes in the trigonal symmetry (proposed space group P3m1), where inorganic zincophosphate chains form layers due to the half occupancy of the unique crystallographic zinc site. The layers are separated from each other by p‐phenylenediammonium dications with hydrogen bonding scheme involving the ammonium protons that reveals a pillar‐like 3D structure aspect. The compound was characterized by powder X‐ray diffraction, multinuclear solid‐state NMR, scanning electron microscopy, chemical analysis, and thermogravimetric analysis.     

New Borate‐citrate: Synthesis,Structure, and Properties of Sr[B(C6H5O7)2](H2O)4·3H2O

Single crystals of Sr[B(C₆H₅O₇)₂](H₂O)₄ · 3H₂O, a new borate‐citrate material, were grown with sizes up to 8 × 6 × 2 mm by slow evaporation of water at room temperature. The structure of Sr[B(C₆H₅O₇)₂](H₂O)₄ · 3H₂O was determined by single‐crystal X‐ray diffraction. It crystallizes in the monoclinic space group P2₁/c, with a = 11.363(3) Å, b = 18.829(4) Å, c = 11.976(3) Å, β = 110.736(3)°, and Z = 4. The SrO₈ dodecahedra, BO₄ tetrahedra and citrate groups are linked together to form chains. The compound was characterized by IR and UV/Vis/NIR transmittance spectroscopy as well as thermal analysis.     

Degradation thermique et etude vibrationnelle de MII(NH4)4(P3O9)2x4H2O(M II=Cu2+, Ni2+, Co2+)

We have studied the thermal behaviour under atmospheric pressure of isotypic tetrahydrate cyclotriphosphates M^II(NH₄)₄(P₃O₉)₂x4H₂O (M ^II=Cu, Ni and Co), between 25 and 1400°C, by X-ray diffraction, thermal analyses (TG and DTA) and infrared spectrometry. This study shows that the series of the compounds M^II(NH₄)₄(P₃O₉)₂x4H₂O (M ^II=Cu, Ni and Co) after elimination of water, in two different stages, and ammonia leads, at 400°C to cyclotetraphosphate M₂ ^IIP₄O₁₂ crystallized and to a thermal residue with a formula H₄P₄O₁₂ which undergoes under a thermal degradation by evolving water and pentoxide phosphorus. The kinetic characteristics of the dehydration and elimination of ammonia have been determinated. The vibrational spectra of Cu(NH₄)₄(P₃O₉)₂x4H₂O were examined and interpreted, in the domain of the valency frequencies, on the basis of the crystalline structure of its isotypic compound Co(NH₄)₄(P₃O₉)₂x4H₂O whose cycle has the site symmetry C₁, of our results of the calculation of the IR frequencies and the successive isotopic substitutions of the equivalent atoms (3P, 3Oi and 6Oe belonging to the P₃Oi₃Oe₆ ring) of the P₃O₉ ³⁻ cycle with high symmetry D_3h. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis,characterization and crystal structure of a 1D heteropolytungstate [4,4′-bipyH2]2[4,4′-bipyH][PCoW11O39]·H2O

A chain-like structure compound [4,4′-bipyH₂]₂[4,4′-bipyH][PCoW₁₁O₃₉]?·?H₂O, in which lacunary polyoxoanions are joined by a Co–O–W bridge, was prepared through the hydrothermal method and characterized by IR, and X-ray crystallography. The title compound crystallizes in a monoclinic lattice, P2₁/n space group, with a?=?13.643 (3), b?=?27.052(5), c?=?15.180(3)?Å, β?=?100.63(3)°, V?=?5506.2(19)?ų, Z?=?4, R ₁?=?0.0792, wR ₂?=?0.1532. Cobalt-substituted Keggin-type subunits are connected via Co–O–W bridges to form a 1D, chainlike, polymolecular Keggin POM. TG-DTA analysis indicates the title compound decomposes at 553°C.     

Strontium chromium(II) diphosphate,SrCrP2O7

The structure of the title compound, SrCrP₂O₇, belongs to the series of isotypic crystal structures SrMP₂O₇ (M = Cr, Mn, Fe, Co, Ni, Cu, Zn or Cd) and is closely related to α‐Ca₂P₂O₇. Chromium(II) shows a 4+1 square‐pyramidal coordination by oxy­gen. [CrO₅] units and the [P₂O₇] groups build a three‐dimensional framework with channels along the a axis, and Sr occupies these channels. In addition to the work on SrCrP₂O₇, lattice parameters for SrMnP₂O₇ have been determined for the first time and unit‐cell dimensions for SrZnP₂O₇ have been redetermined.     

Thermal Analysis of the System Li2WO4-Li4P2O7-WO3

The system Li₂WO₄-Li₄P₂O₇-WO₃ in the range of WO₃ contents of up to 60 mol % was studied by thermal analysis. In the examined range of the composition triangle, the crystallization fields of lithium tungstate and pyrophosphate, of congruently melting compound D (Li₂WO₄·WO₃), and of incongruently melting compound D ₂ (2Li₂WO₄·Li₄P₂O₇) were revealed, and the glass formation region was established. Low-melting compositions showing promise for synthesis of lithium-tungsten oxide bronzes were revealed.     

[Ni(H2O)6]2[Na(H2O)3]2[V10O28]·4H2O,bis(nickel hexahydrate) bis(sodium trihydrate) decavanadate tetrahydrate

Polyoxometallates are capable of including transition metals in their crystal structures as either discrete cations or heteroatoms. The title compound crystallizes with triclinic symmetry and consists of a centrosymmetric [V₁₀O₂₈]^6? anion, a trimeric {[Na(H₂O)₃][Ni(H₂O)₆][Na(H₂O)₃]}⁴⁺ cation, an [Ni(H₂O)₆]²⁺ cation and four water molecules of crystallization. The compound possesses two Ni atoms (each on independent inversion centres), one as a discrete cation and one in a disodium–nickel trimeric cation involved in the one‐dimensional polycation–polyanion hybrid polymer. The polymers are bound together via hydrogen bonds to the water mol­ecules and the nickel(II) hexahydrate cation. Several structures of decavanadate compounds having transition metal atoms, monovalent cations and [V₁₀O₂₈]^6? anions in the ratio 2:2:1 have been reported previously. However, the present compound differs from these in its arrangement of monovalent cations and transition metal atoms.     

Synthesis,Crystal Structure and Magnetic Properties of [Fe(bpe)4(H2O)2](TCNQ)2 (bpe = trans‐1,2‐bis(4‐pyridyl)ethane and TCNQ = tetracyanoquinodimethane)

The synthesis, structure and magnetic properties of [Fe(bpe)₄(H₂O)₂](TCNQ)₂ ( 1 ) are reported. 1 crystallizes in the triclinic P space group, a = 13.481(5), b = 14.887(3), c = 16.663(4) Å, α = 101.048(18), β = 112.84(2), γ = 90.92(2)°, V = 3009.6(14) ų, Z = 2. The iron atom defines a compressed octahedron with the equatorial positions occupied by the bpe molecules which act as monodentate ligands and the two axial positions occupied by water molecules. The TCNQ^? radical counterions are uncoordinated and interact by pairs defining (TCNQ)₂^2? units strongly coupled antiferromagnetically. The iron(II) atoms are in the high spin state and its magnetic behaviour indicates the occurrence of zero‐field splitting of the S = 2 ground state.     

Sol-Gel Synthesis and Characterization of SiO2—P2O5—ZrO2

Zirconia phosphosilicates were prepared by the sol-gel method using tetraethylorthosilicate, triethyl phosphate, and zirconium n-propoxide. Monolithic, transparent gels were formed with 10 mole% ZrO₂, and 10, 20 or 30 mole% P₂O₅. The influence of the mole% P₂O₅, treatment temperature and water content, on thermal behavior, water adsorption, and proton conductivity were studied. A heat treatment at 200°C was effective in removal of residual organics, creating a porous material capable of good water retention upon rehydration.