Synthesis and X-ray diffraction study of [UO<Subscript>2</Subscript>(NO<Subscript>3</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 2C<Subscript>12</Subscript>H<Subscript>18</Subscript>O

The compound [UO₂(NO₃)₂(H₂O)₂] · 2C₁₂H₁₈O was synthesized and studied by IR spectroscopy and X-ray diffraction. The structure consists of the neutral island groups [UO₂(NO₃)₂(H₂O)₂], which belong to the crystal-chemical group AB ⁰¹ ₂ M ¹ ₂ (A = UO₂ ²⁺, B ⁰¹ = NO₃⁻, M ¹ = H₂O) of uranyl complexes, and 1-adamantyl methyl ketone molecules. The characteristic features of the association of the complexes [UO₂(NO₃)₂(H₂O)₂] and 1-adamantyl methyl ketone molecules in the crystal structure via hydrogen bonds are considered with the use of Voronoi-Dirichlet polyhedra.     

Synthesis,Crystal Structure and Spectral Properties of [Fe<Subscript>3</Subscript>(2,2′-bipy)<Subscript>6</Subscript>(ox)<Subscript>3</Subscript>]·12.25H<Subscript>2</Subscript>O Complex

A novel iron (II) complex of formula [Fe₃(2,2′-bipy)₆(ox)₃]·12.25H₂O (2,2′-bipy = 2,2′-bipyridine, ox = oxalate) has been prepared and structurally characterized by X-ray crystallography. In the complex, the metal atoms are six-coordinated in distorted octahedral environment. In the complex [Fe(ox)₃]^4? anions and water molecules are linked together into 1D chain structure by hydrogen interaction. The red crystal of the complex is monoclinic, space group P2₁/c, with a = 22.932(6) Å, b = 13.715(4) Å, c = 22.493(6) Å, β = 93.177(5)°, and V = 7063(3) Å³ with Z = 4.     

Synthesis and crystal structure of [UO<Subscript>2</Subscript>CrO<Subscript>4</Subscript>(C<Subscript>5</Subscript>NH<Subscript>5</Subscript>COO)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)]·2H<Subscript>2</Subscript>O

Crystals of UO₂CrO₄(C₅NH₅COO)₂(H₂O)] · 2H₂O are synthesized and their structure is studied by X-ray diffraction. The compound crystallizes in the triclinic crystal system. The unit cell parameters are as follows: a = 7.0834(10) Å, b = 10.6358(14) Å, c = 12.9539(17) Å, α = 75.096(2)°, β = 74.490(2)°, and γ = 80.657(2)°; V = 904.1(2) ų, space group P \(\bar 1\), Z = 2, and R = 0.026. The structure is built of [UO₂CrO₄(C₅NH₅COO)₂(H₂O)]₂ centrosymmetric dimers, which are linked into a framework by a system of hydrogen bonds involving inner-sphere and outer-sphere water molecules. The coordination number of the U(VI) atom is seven, and the coordination polyhedron is a pentagonal bipyramid with the oxygen atoms of the uranyl group, two chromate groups, two molecules of isonicotinic acid, and a water molecule at the vertices. The crystal chemical formula of the [UO₂CrO₄(C₅NH₅COO)₂(H₂O)]₂ dimer is represented as AB ² M ₃ ¹ , where AB ² M ₃ ¹ , where A = UO ₂ ²⁺ , B ² = CrO ₄ ^2? , and M ¹ = = C₅NH₄COOH and H₂O.     

Synthesis and structure of a new hybrid vanadium arsenate: [VO<Subscript>2</Subscript>(phen)]<Subscript>2</Subscript>(H<Subscript>2</Subscript>AsO<Subscript>4</Subscript>)⋅H<Subscript>3</Subscript>O

A new hybrid vanadium arsenate [VO₂(phen)]₂(H₂AsO₄)H₃O 1 (phen = 1,10-phenanthroline) was synthesized under hydrothermal reaction conditions and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis (TGA), IR and elemental analyses. Crystal data for 1: monoclinic, P2₁/n, a = 9.175(2) Å, b = 18.638(5) Å, c = 14.482(4) Å, = 102.333(3), V = 2419(1) ų, Z = 4. Compound 1 is composed of discrete tricyclic (VO₂)₂(H₂AsO₄) cluster decorated with two phen ligands. The discrete arsenic–vanadium clusters are extended into three-dimensional supramolecular arrays via – stacking interactions of phen groups.     

Synthesis and Crystal Structure of [Ni(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(pdc)(4-CNpy)] · 2H<Subscript>2</Subscript>O (pdc = Pyridine-2,6-dicarboxylate, 4-CNpy = 4-cyanopyridine)

Abstract A new complex containing two different substituted pyridine ligands, viz. 4-CNpy (4-cyanopyridine) and pdc (pyridine-2,6-dicarboxylate), [Ni(H₂O)₂(pdc)(4-CNpy)] · 2H₂O (1), has been prepared using [Ni(4-CNpy)₂(H₂O)₃(SO₄)] · H₂O (2) as the starting compound. Crystal data on 1 are: monoclinic, P2₁/c, a = 11.533(2) ?, b = 20.114(4) ?, c = 7.306(1) ?, β = 93.777(3)°, V = 1,691.1(5) ?³, Z = 2, D _calc. = 1.57 g cm⁻³, R ₁ = 0.0585, w R ₂ = 0.1236 for reflections with I > 4σ(F ₀) and 268 parameters (R ₁ = 0.0859, wR ₂ = 0.1336 for all 4,024 reflections). The discrete molecules of the title complex remain hydrogen-bonded to assemble into supramolecular layers interleaved by disordered water molecules. In an attempt to obtain the cationic complex species cis-[Ni(H₂O)₄(4-CNpy)₂]²⁺ we have isolated the compound [Ni(H₂O)₄(4-CNpy)₂] · (BPh₄)₂ · 2(4-CNpy) · 4H₂O (3) by adding NaBPh₄ to an aqueous solution of 2. Crystal data on 3 are: monoclinic, P2₁/n, a = 10.5002(1) ?, b = 21.1692(3) ?, c = 15.3249(2) ?, β = 95.120(1)°, V = 3392.84(7) ?³, Z = 2, D _calc. = 1.231 g cm⁻³, R ₁ = 0.0453, wR ₂ = 0.1217 for reflections with I > 4σ (F ₀) and 556 parameters (R ₁ = 0.0688, wR ₂ = 0.1364 for all 9,257 reflections). Index Abstract Synthesis and Crystal Structure of [Ni(H₂O)₂(pdc)(4-CNpy)] · 2H₂O (pdc = Pyridine-2,6-dicarboxylate, 4-CNpy = 4-cyanopyridine) Manjit K. Bhattacharyya, Sanchay J. Bora and Birinchi K. Das Crystal structure of a new nickel(II) complex displaying a supramolecular layered structure is described. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and Crystal Structure of a Novel Supramolecular Complex: [Co(2-Me-3,4-qudc)(Phen)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)]·4.5H<Subscript>2</Subscript>O

Abstract  

A novel 3D supramolecular complex, [Co(2-Me-3,4-qudc)(Phen)₂(H₂O)] 4.5H₂O (2-Me-3,4-qudc = 2-methylquinoline-3,4-dicarboxylate dianion, phen = 1,10-phenanthroline), has been synthesized under mild condition and characterized by elemental analyses, IR spectrum, thermogravimetric analysis and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P2₍₁₎ /n with unit cell parameters a = 13.1701(12) ?, b = 18.6728(19) ?, c = 15.0683(16) ?, β = 13.617(2), V = 3395.3(6) ?³, Z = 4. The 3D framework of the title compound is formed via O–H⋯O hydrogen-bonds and π–π stacking interactions. The lattice waters are stable at room temperature, but when thermally decomposed, the water loss is irreversible.     

Synthesis and crystal structure of binuclear molecule Ho<Subscript>2</Subscript>(2-FC<Subscript>6</Subscript>H<Subscript>4</Subscript>COO)<Subscript>6</Subscript>⋅4H<Subscript>2</Subscript>O

The complex Ho₂(2-FC₆H₄COO)₆?4H₂O has been synthesized and structurally characterized by single crystal X-ray diffraction methods. The complex crystallizes in the triclinic system with space group P \(\bar 1\), lattice parameters a = 9.293(8) Å, b = 9.845(8) Å, c = 12.703(11) Å, α = 85.470(14)^°, β = 87.537(12)^°, γ = 62.485(11)^°, V = 1027.5(15) ų, Z = 1, D_calc = 1.998 Mg/m³. The Ho³⁺ ion is in distorted monocapped square-antiprism coordination environment and is coordinated by nine oxygen atoms, seven from five 2-FC₆H₄COO^2? groups, two from two water molecules. Two Ho³⁺ ions are linked together by four bridging carboxylate groups to form a binuclear molecule with inversion center.     

Synthesis and crystal structure of Na<Subscript>3</Subscript>(H<Subscript>3</Subscript>O)[UO<Subscript>2</Subscript>(SeO<Subscript>3</Subscript>)<Subscript>2</Subscript>]<Subscript>2</Subscript>· H<Subscript>2</Subscript>O

Single crystals of the compound Na₃(H₃O)[UO₂(SeO₃)₂]₂ · H₂O (I) have been synthesized, and their structure has been investigated using X-ray diffraction. Compound I crystallizes in the triclinic system with the unit cell parameters a = 9.543(6)Å, b = 9.602(7)Å, c = 11.742(8)Å, α = 66.693(16)°, β = 84.10(2)°, γ = 63.686(14)°, space group P \(\bar 1\), Z = 2, and R = 0.0734. The uranium-containing structural units of the crystals are [UO₂(SeO₃)₂]^2? chains, which belong to the crystal-chemical group AB ² B ¹¹ (A = UO ₂ ²⁺ , B ² = SeO ₃ ^2? , B ¹¹ = SeO ₃ ^2? ) of the uranyl complexes. The structures of the compounds containing the [UO₂(SeO₃)₂]^2? anionic complexes are compared.     

Crystal Structure and Physical Characterisation of [Zn<Subscript>2</Subscript>(Benzoato)<Subscript>4</Subscript>(Caffeine)<Subscript>2</Subscript>]·2 Caffeine

Abstract  

The crystal structure of [Zn₂(benzoato)₄(caffeine)₂]·(caffeine)₂ was determined by direct method and Fourier technique. The structure was refined by full-matrix least-squares method to a weighted R factor of 0.0582. The structure consists of centrosymmetric dimeric units where the two zinc(II) atoms are coordinated by four bridging benzoates in a syn–syn arrangement and two caffeine ligands at the apices of a bicapped square prism. Remaining two caffeines are bound only by hydrogen bonds. The Zn–Zn distance is 2.961(1) ?. The Zn(II) atoms are displaced by 0.365 ? from the basal plane containing four oxygen atoms towards the apical caffeine molecules. The dimeric structure of the complex is consistent with spectrum and thermal data. The structural data are compared with those found in similar [Zn₂(RCOO)₄(NL)₂] complexes.     

X-ray diffraction study of Rb<Subscript>2</Subscript>[(UO<Subscript>2</Subscript>)<Subscript>2</Subscript>(CrO<Subscript>4</Subscript>)<Subscript>3</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The compound Rb₂[(UO₂)₂(CrO₄)₃(H₂O)₂] · 4H₂O was studied by X-ray diffraction. The crystals are monoclinic, a = 10.695(2) Å, b = 14.684(3) Å, c = 14.125(3) Å, β = 108.396(4)°, sp. gr. P2₁/c, Z = 4, V = 2104.9(7) ų, and R = 0.0491. The main structural units are layers consisting of [(UO₂)₂(CrO₄)₃(H₂O)₂]^2? anions belonging to the crystal-chemical group A ₂ T ₂ ³ B ²M ₂ ¹ (A = UL ₂ ²⁺ , T ³ and B ² are CrO ₄ ^2? , and M ¹ is H₂O) of uranyl complexes. The uranium-containing layered groups are held together by electrostatic interactions with rubidium cations, as well as by hydrogen bonds with the participation of inner- and outer-sphere water molecules.     

Crystal structure and properties of K<Subscript>2</Subscript>[OsO<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O

The synthesis and X-ray diffraction study of the compound K₂[OsO₂(C₂O₄)₂] · 2H₂O are performed. The compound crystallizes in the triclinic crystal system, space group P \(\bar 1\), a = 6.545(1) Å, b = 6.835(2) Å, c = 7.595(2) Å, α = 85.76(2)°, β = 65.33(2)°, γ = 71.14(2)°, and Z = 1. The osmium atom is located at the center of symmetry and has a distorted octahedral coordination formed by oxygen atoms: two oxygen atoms of the osmyl group occupy the apical positions [Os-O, 1.730(2) Å], and four oxygen atoms of the oxalate ions lie in the equatorial plane. The K⁺ cation is surrounded by ten oxygen atoms located at different K-O distances in the range from 2.787(2) to 3.158(2) Å. The assignment of the absorption bands in the IR spectrum of K₂[OsO₂(C₂O₄)₂] · 2H₂O is performed. The electronic absorption spectra of the compound are recorded in different solvents, and the thermal behavior in air is studied.     

Synthesis and Crystal Structure of the Heteronuclear Decavanadates Complex: [Fe(phen)<Subscript>3</Subscript>]<Subscript>2</Subscript>·[V<Subscript>10</Subscript>O<Subscript>28</Subscript>]·15H<Subscript>2</Subscript>O

Abstract  

A new decavanadate metal complex [Fe(phen)₃]₂·[V₁₀O₂₈]·15H₂O (phen = 1,10-phenanthroline) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The crystal structure analysis reveals that the polyoxoanions are decorated with the [Fe(phen)₃]³⁺ cations, and that the water molecules play the bridge role on the packing modes. They are further contacted to form supramolecular networks through extensive hydrogen bonding.     

Crystal structure of byelorussite-(Ce) NaMnBa<Subscript>2</Subscript>Ce<Subscript>2</Subscript>(TiO)<Subscript>2</Subscript>[Si<Subscript>4</Subscript>O<Subscript>12</Subscript>]<Subscript>2</Subscript>(F,OH) · H<Subscript>2</Subscript>O

The crystal structure of the mineral byelorussite-(Ce) NaMnBa₂Ce₂Ti₂Si₈O₂₆(F,OH) · H₂O belonging to the joaquinite group was solved and refined to R = 0.033 based on 4813 reflections with I > σ2(I). The parameters of the orthorhombic unit cell are a = 22.301(4) Å, b = 10.514(2) Å, c = 9.669(2) Å, V = 2267.1(8) ų, sp. gr. Ama2, and Z = 4. The structure is composed of three-layer sheets, which consist of dimers of edge-sharing Ti octahedra located between isolated four-membered [Si₄O₂] rings. The sheets are linked to each other by Mn 5-vertex polyhedra to form a heteropolyhedral framework. Large cavities in the framework are occupied by Na 6-vertex polyhedra, Ba 11-vertex polyhedra, and REE 9-vertex polyhedra.     

Crystal structure and properties of [OsO<Subscript>2</Subscript>(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>]SO<Subscript>4</Subscript> · H<Subscript>2</Subscript>O

The structure of a single crystal of tetraammindioxoosmium(VI) sulfate [OsO₂(NH₃)₄]SO₄ · H₂O, which is synthesized by the reaction of K₂[OsO₂(OH)₄] with (NH₄)₂SO₄ in an aqueous solution, is investigated using X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system, space group P2₁/c, a = 13.102(2) Å, b = 6.158(3) Å, c = 11.866(2) Å, β = 98.13(2)°, and Z = 4. The [OsO₂(NH₃)₄]SO₄ · H₂O compound has an island structure. Two crystallographically independent osmium atoms are situated at the centers of symmetry, and their octahedral coordination includes two oxygen atoms and four nitrogen atoms of the ammonia molecules. In both octahedra, the osmyl group is linear. The Os-O distances in the octahedra are identical within the standard deviations [Os(1)-O, 1.762(2) Å; Os(2)-O, 1.769(2) Å]. The Os-N bond lengths vary from 2.082(3) to 2.101(3) Å. The cationic complexes, SO₄ groups, and water molecules are linked via the system of hydrogen bonds. The assignment of the absorption bands in the IR spectrum of the compound synthesized is performed, and its thermal behavior in air is studied.     

Synthesis and Characterization of <Emphasis Type="Italic">Cis</Emphasis>-[V<Superscript>IV</Superscript>O(pzc)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)]·2H<Subscript>2</Subscript>O (pzc: 2-pyrazinecarboxylate)

Abstract  

Hydrothermal synthesis and the structural characterization of V(IV) complex of 2-pyrazinecarboxylate (pzc), is reported. The vanadium is in a distorted octahedral environment. Pairs of pyrazine-2-carboxylate ligands are always cis to each other. The pzc ligands do not link adjacent vanadium atom directly. The remainder of the three-dimensional network is completed by intense hydrogen bonding of uncoordinated water molecules to aqua and pzc ligands. Cis-[V^IVO(pzc)₂(H₂O)]·2H₂O, 1, was characterized by means of elemental analysis (CHNS), TGA, FT-IR, manganometric titration, bond valance sum calculations and single crystal X-ray diffraction methods. Crystal data for 1: monoclinic space group P2 ₁ /c and unit-cell parameters are a = 9.1142(5), b = 16.5822(10), c = 12.8936(7) ?, β = 131.625(3)° and Z = 4. To the best of our knowledge, cis-[V^IVO(pzc)₂(H₂O)] is reported without single crystal structure by Eugenio Garribba and his colleagues in year 2006. Herein we complete full characterization of the title complex with single crystal structure and also 1 will be the first reported example of solid vanadium complex of 2-pyrazinecarboxylates involving intense hydrogen bonding.     

Synthesis,Structure and Luminescent Property of a Novel Lanthanide Metal-Organic Coordination Polymer Yb<Subscript>3</Subscript>(BDC)<Subscript>4.5</Subscript>(DMF)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>3</Subscript> · (DMF)<Subscript>2</Subscript>

Abstract  A three-dimensional lanthanide metal-organic coordination polymer Yb₃(BDC)_4.5(DMF)₂(H₂O)₃ · (DMF)₂ has been synthesized by the reaction of the lanthanide metal ion (Yb³⁺) with 1,4-benzenedicarboxylic acid (H₂BDC) under mild condition. The compound crystallizes in the triclinic system, space group PI with unit cell parameters a = 10.7428(9) Å, b = 11.2786(9) Å, c = 26.172(2) Å, α = 85.060(2)°, β = 88.1060(10)°, γ = 62.3670(10)°, V = 2798.9 (4) ų, Z = 2. The crystal structure exhibits one-dimensional channels along the [011] direction. The fluorescent results showed that there were two emission peaks at 375 and 420 nm when the compound was excited by a 235 nm excitation. Graphical Abstract  The preparation, X-ray structure and luminescent property are presented for a new lanthanide metal-organic coordination polymer Yb₃(BDC)_4.5(DMF)₂(H₂O)₃ · (DMF)₂.      

New Diphosphopentamolybdate K<Subscript>5</Subscript>[HP<Subscript>2</Subscript>Mo<Subscript>5</Subscript>O<Subscript>23</Subscript>] · 10H<Subscript>2</Subscript>O: Synthesis,Structure, and Characterization

A new diphosphopentamolybdate(VI) K₅[HP₂Mo₅O₂₃] · 10H₂O has been prepared employing solution method and characterized by single crystal X-ray diffraction, energy dispersive analysis, infrared spectroscopy, thermal stability analysis, cyclic voltammetry analysis, and ultraviolet visible spectroscopy. The compound crystallizes in the orthorhombic sp. gr. Pcab: a = 15.9661(10) Å, b = 19.0832(10) Å, c = 20.0970(9) Å, V = 6123.27(10) Å3, Z = 8. The crystal structure contains the polyanion units [HP₂Mo₅O₂₃]^5– around the potassium cations and lattice water. The [HP₂Mo₅O₂₃]^5– subunits are connected together through K?O?Mo bridges and hydrogen bonds. The crystal shape morphology was simulated using the Bravais–Friedel–Donnay–Harker model.     

Synthesis and Crystal Structure of [Na(H<Subscript>2</Subscript>O)<Subscript>1.5</Subscript>][Na(H<Subscript>2</Subscript>O)<Subscript>3.5</Subscript>] X<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O (X = 4′-Methoxy-7-Hydroxyisoflavone-3′-Sulfonate)

Abstract  

Water-soluble derivative of formononetin, [Na(H₂O)_1.5][Na(H₂O)_3.5] X₂·2H₂O(X = 4′-methoxy-7-hydroxyisoflavone-3′-sulfonate) was synthesized by sulfonation reaction. It was characterized by IR, ¹H NMR and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis showed that the title compound crystallized in a triclinic space group P-1 with cell parameters a = 6.9642(15) ?, b = 13.343(3) ?, c = 20.634(5) ?, α = 107.115(3)˚, β = 93.121(4)˚, γ = 91.911(3)˚, V = 1827.3(7) ?⁻³, D _c  = 1.575 Mg m ⁻³, Z = 2. There are two conformers of 4′-methoxy-7-hydroxyisoflavone-3′-sulfonate anions, two kinds of sodium cations, five coordinated water molecules and two lattice water molecules in the crystal structure. The sodium atoms coordinated with the oxygen atoms from water molecules, hydroxyl groups and sulfo-groups to form a Na–O coordinated network. Aromatic π···π stacking interactions and hydrogen bonding existed in the crystal structure of title compound, which together with coordinated interactions and electrostatic interactions between sodium cations and anions sulfonates C₁₆H₁₀O₄SO₃ ⁻ lead to the moieties into a three-dimensional network.     

Synthesis and Crystal Structure of 2D Supramolecular Compound [Co(phth)(phen) (H<Subscript>2</Subscript>O)<Subscript>3</Subscript>]·H<Subscript>2</Subscript>O

Abstract  

A 2D supramolecular compound [Co(phth)(phen) (H₂O)₃]·H₂O has been synthysized by the reactions of Co(NO₃)₂·6H₂O, 1, 10-phenanthroline(phen) and phthalate acid(H₂phth) in NaOH solution with pH 7.0.The complex has been characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis which shows it belongs the monoclinic space group P2(1)/n, a = 7.571(2) ?, b = 13.737(3) ?, c = 20.015(4) ?, β = 95.56(1)°. V = 2071.9(8) ?³, Mr = 475.31, Dc = 1.524 g/cm⁻³, Z = 4, F(000) = 980, μ(MoKa) = 0.879 mm⁻¹. The final R1 and wR2 are 0.0348 and 0.0711, respectively. The cobalt(II) ion is six-coordinated in a distorted octahedron to form a unit. Every unit is connected by hydrogen bonds forming 1D chain and 2D supramolecular network by π–π stacking interaction between adjoining chains.     

AErP<Subscript>2</Subscript>O<Subscript>7</Subscript> (A = Rb,Cs) and HEuP<Subscript>2</Subscript>O<Subscript>7</Subscript>·3H<Subscript>2</Subscript>O: Crystal Structures,Vibrational Studies and Thermal Behaviours

Abstract  

New diphosphates AErP₂O₇, A = Rb (1), Cs (2), and HEuP₂O₇·3H₂O (3) have been prepared via soft chemistry route from evaporation of aqueous solution. Their crystal structures have been solved by single crystal diffraction data. The compounds (1) and (2) crystallize in the monoclinic space group P2₁/c with the following unit cell dimensions: (1) a = 7.7248(4) ?, b = 10.9342(6) ?, c = 8.6716(3) ?, β = 105.434(4)° and Z = 4; (2) a = 7.9192(4) ?, b = 10.8606(4) ?, c = 8.7684(5) ?, β = 104.317(5)° and Z = 4. Compound (3) crystallises in the triclinic space group P − 1, with the unit cell parameters: a = 6.4036(5) ?, b = 6.8753(6) ?, c = 9.7964(8) ?, α = 81.706(7)°, β = 80.218(7)°, γ = 88.381(7)°. Crystal structure of (1) and (2) consists of 3D open framework built from [ErO₆] octahedra sharing corners with [P₂O₇] units, leading to the formation of channels running along c direction in which A⁺ [A = Rb(1), Cs(2)] ions are located. The compound (3), on the other hand, exhibits a lamellar structure, in which edge-sharing polyhedra of eightfold coordinated europium form chains along [010]. These chains are joined in turn to each others using diphosphates bridges. A network of O–H···O hydrogen bonds reinforces the cohesion of the structure of (3). The diphosphate groups in (1), (2) and (3) adopts an eclipsed configuration. IR and Raman spectra of the three new phosphates show usual signals related to the P₂O₇ diphosphate group and the water molecule. TG and DTA studies were carried out on crystals of (3). The data are correlated to the crystal structures ones.