Tetradecacobalt(II)‐Containing 36‐Niobate [Co14(OH)16(H2O)8Nb36O106]20− and Its Photocatalytic H2 Evolution Activity

A gigantic Co₁₄‐containing 36‐niobate, Na₁₂K₈[Co₁₄(OH)₁₆(H₂O)₈Nb₃₆O₁₀₆] ? 71H₂O ( 1 ), has been prepared by the hydrothermal method and structurally characterized. Polyanion [Co₁₄(OH)₁₆(H₂O)₈Nb₃₆O₁₀₆]^20? ( 1 a ) comprises a central Co₇ core, surrounded by another seven isolated Co²⁺ ions and six Lindqvist‐type (Nb₆O₁₉) hexaniobate fragments. This is the first example of a high‐nuclear cobalt‐cluster‐containing polyoxoniobate. The photocatalytic H₂ evolution activity of Pt‐loaded 1 was observed in methanol solution under irradiation using a 300 W Xe lamp.     

Sm2As4O9: Ein ungewöhnliches Samarium(III)‐Oxoarsenat(III) gemäß Sm4[As2O5]2[As4O8]

Sm₂As₄O₉: An Unusual Samarium(III) Oxoarsenate(III) According to Sm₄[As₂O₅]₂[As₄O₈] Pale yellow single crystals of the new samarium(III) oxoarsenate(III) with the composition Sm₄As₈O₁₈ were obtained by a typical solid‐state reaction between Sm₂O₃ and As₂O₃ using CsCl and SmCl₃ as fluxing agents. The compound crystallizes in the triclinic crystal system with the space group (No. 2, Z = 2; a = 681.12(5), b = 757.59(6), c = 953.97(8) pm, α = 96.623(7), β = 103.751(7), γ = 104.400(7)°). The crystal structure of samarium(III) oxoarsenate(III) with the formula type Sm₄[As₂O₅]₂[As₄O₈] (≡ 2 × Sm₂As₄O₉) contains two crystallographically different Sm³⁺ cations, where (Sm1)³⁺ is coordinated by eight, but (Sm2)³⁺ by nine oxygen atoms. Two different discrete oxoarsenate(III) anions are present in the crystal structure, namely [As₂O₅]^4? and [As₄O₈]^4?. The [As₂O₅]^4? anion is built up of two Ψ¹‐tetrahedra [AsO₃]^3? with a common corner, whereas the [As₄O₈]^4? anion consists of four Ψ¹‐tetrahedra with ring‐shaped vertex‐connected [AsO₃]^3? pyramids. Thus at all four crystallographically different As³⁺ cations stereochemically active non‐binding electron pairs (“lone pairs”) are observed. These “lone pairs” direct towards the center of empty channels running parallel to [010] in the overall structure, where these “empty channels” being formed by the linkage of layers with the ecliptically conformed [As₂O₅]^4? anions and the stair‐like shaped [As₄O₈]^4? rings via common oxygen atoms (O1 – O6, O8 and O9). The oxygen‐atom type O7, however, belongs only to the cyclo‐[As₄O₈]^4? unit as one of the two different corner‐sharing oxygen atoms.     

Organoantimony(III)‐Containing Tungstoarsenates(III): From Controlled Assembly to Biological Activity

A family of three sandwich‐type, phenylantimony(III)‐containing tungstoarsenates(III), [(PhSb^III){Na(H₂O)}As^III₂W₁₉O₆₇(H₂O)]^11? ( 1 ), [(PhSb^III)₂As^III₂W₁₉O₆₇(H₂O)]^10? ( 2 ), and [(PhSb^III)₃(B‐α‐As^IIIW₉O₃₃)₂]^12? ( 3 ), have been synthesized by one‐pot procedures and isolated as hydrated alkali metal salts, Cs₃K_3.5Na_4.5[(PhSb^III){Na(H₂O)}As^III₂W₁₉O₆₇(H₂O)]?41H₂O ( CsKNa ‐ 1 ), Cs_4.5K_5.5[(PhSb^III)₂As^III₂W₁₉O₆₇(H₂O)]?35H₂O ( CsK‐2 ), and Cs_4.5Na_7.5[(PhSb^III)₃(B‐α‐As^IIIW₉O₃₃)₂]?42H₂O ( CsNa ‐ 3 ). The number of incorporated {PhSb^III} units could be selectively tuned from one to three by careful control of the reaction parameters. The three compounds were characterized in the solid state by single‐crystal XRD, IR spectroscopy, and thermogravimetric analysis. The aqueous solution stability of sandwich polyanions 1 – 3 was also studied by multinuclear (¹H, ¹³C, ¹⁸³W) NMR spectroscopy. Effective inhibitory activity against six different kinds of bacteria was identified for all three polyanions, for which the activity increased with the number of incorporated {PhSb^III} groups.     

Mechanism of Thioether Oxidation over Di‐ and Tetrameric Ti Centres: Kinetic and DFT Studies Based on Model Ti‐Containing Polyoxometalates

The oxidation of thioethers by the green oxidant aqueous H₂O₂ catalysed by the tetratitanium‐substituted Polyoxometalate (POM) (Bu₄N)₈[{γ‐SiTi₂W₁₀O₃₆(OH)₂}₂(μ‐O)₂], as a model catalyst comprising tetrameric titanium centres, was investigated by kinetic modelling and DFT calculations. Several mechanisms of sulfoxidation were evaluated by using methyl phenyl sulfide (PhSMe) as a model substrate in the experiments and dimethyl sulfide in the calculations. The first mechanism assumes that the active hydroperoxo species forms directly through interaction of the Ti₂(μ‐OH)₂ group in [{γ‐SiTi₂W₁₀O₃₆(OH)₂}₂(μ‐O)₂]^8? ( 1 D ) with H₂O₂. The second mechanism includes hydrolysis of Ti‐O‐Ti bonds linking two γ‐Keggin units in structure 1 D to produce the monomer [(γ‐SiW₁₀Ti₂O₃₈H₂)(OH)₂]^4? ( 1 M ), followed by the formation of an active hydroperoxo species upon interaction of the Ti hydroxo group with H₂O₂. Both kinetic modelling and DFT calculations support the mechanism through the monomeric species that involves the hydrolysis step. According to the DFT studies the activation of H₂O₂ by compound 1 M is preferred by 6.5 kcal mol^?1 with respect to anion 1 D due to the more flexible Ti environment of the terminal Ti hydroxo group in 1 M . The calculations also indicate that for the ?monomeric“ mechanism two pathways are operative: the mono‐ and the multinuclear pathway. In the mononuclear mechanism, the active group is the terminal Ti?OH group, whereas in the multinuclear path the active group is the bridging Ti₂(μ‐OH) moiety. Moreover, unlike previous studies, the sulfoxidation is preferred through a β‐oxygen atom transfer from the Ti hydroperoxo group because the α‐oxygen atom transfer leads to an unfavourable seven‐fold coordinated Ti environment in the transition state. Finally, we have generalised these results to other Ti‐containing POMs: the Ti‐monosubstituted α‐Keggin ion [α‐PTi(OH)W₁₁O₃₉]^4? and the dititanium‐substituted sandwich‐type ion [Ti₂(OH)₂As₂W₁₉O₆₇]^8?.     

Two New Polyoxovanadate‐supported Transition Metal Complexes: [Zn(en)2][Zn(en)2(H2O)2][{Zn(en)(enMe)}As6V15O42(H2O)]·4H2O and [Zn2(enMe)2(en)3][{Zn(enMe)2}As6V15O42(H2O)]·4H2O

Two novel As‐V‐O cluster supported transition metal complexes, [Zn(en)₂][Zn(en)₂(H₂O)₂][{Zn(en)(enMe)}As₆V₁₅O₄₂(H₂O)]·4H₂O ( 1 ) and [Zn₂(enMe)₂(en)₃][{Zn(enMe)₂}As₆V₁₅O₄₂(H₂O)]·4H₂O ( 2 ), have been hydrothermally synthesized. The single X‐ray diffraction studies reveal that both compounds consist of discrete noncentral polyoxoanions [{Zn(en)(enMe)}As₆V₁₅O₄₂(H₂O)]^4? or [{Zn(enMe)₂}As₆V₁₅O₄₂(H₂O)]^4? cocrystallized with respective zinc coordination complexes. Interestingly, compounds 1 and 2 exhibit the first two polyoxovanadates containing As₈V₁₅O₄₂‐(H₂O)]^6? cluster decorated by only one transition metal complex. Crystal data: 1 , monoclinic, P2₁/n, a = 14.9037(4) Å, b = 18.1243(5) Å, c = 27.6103(7) Å, β = 105.376(6)°, Z = 4; 2 monoclinic, P2₁/n, a = 14.9786(7) Å, b = 33.0534(16) Å, c = 14.9811(5) Å, Z = 4.     

Co(en)3[B4O5(OH)4]Cl·3H2O和[Ni(en)3][B5O6(OH)4]2·2H2O的合成、结构以及热力学性质

利用水热法合成了两种过渡金属配合物为模板剂的含水硼酸盐晶体Co(en)3[B4O5(OH)4]Cl·3H2O(1) 和 [Ni(en)3][B5O6(OH)4]2·2H2O (2),并通过元素分析、X射线单晶衍射、红外光谱及热重分析对其进行了表征。化合物1晶体结构的主要特点是在所有组成Co(en)33+, [B4O5(OH)4]2–, Cl– 和 H2O之间通过O–H…O、O–H…Cl、N–H…Cl和N–H…O四种氢键连接形成网状超分子结构。化合物2晶体结构的特点是[B5O6(OH)4]–阴离子通过O–H…O氢键连接形成沿a方向有较大通道的三维超分子骨架,模板剂[Ni(en)3]2+阳离子和结晶水分子填充在通道中。     

Preparations,Structures and Luminescence Properties of Penta‐rare‐earth Incorporated Tetravacant Dawson Selenotungstates and Their Ho3+/Tm3+ Co‐doped Derivatives

A family of penta‐rare‐earth incorporated tetravacant Dawson selenotungstates [H₂N(CH₃)₂]₁₀H₃[SeO₄RE₅(H₂O)₇(Se₂W₁₄O₅₂)₂] ? 40H₂O [RE=Ho³⁺ ( 1 ), Er³⁺ ( 2 ), Tm³⁺ ( 3 ), Tb³⁺ ( 4 )] were synthesized. It should be noted that a penta‐RE [SeO₄RE₅(H₂O)₇]¹¹⁺ central core connecting two tetra‐vacant Dawson‐type [Se₂W₁₄O₅₂]^12? subunits generates a dimeric assembly of [SeO₄RE₅ (H₂O)₇(Se₂W₁₄O₅₂)₂]^13? in the structures of 1 – 4 . Meanwhile, a class of Ho³⁺/Tm³⁺ co‐doped derivatives based on 1 with a Ho³⁺/Tm³⁺ molar ratio of 0.75:0.25–0.25:0.75 were also prepared and characterized by energy‐dispersive spectroscopy (EDS) analyses. Moreover, their luminescence properties were systematically investigated, which indicate that Tm³⁺ ions can sensitize the emission of Ho³⁺ ions in the visible region and prolong the fluorescence lifetime of Ho³⁺ ions to some extent. Energy transfer from Tm³⁺ ions to Ho³⁺ ions was probed by time‐resolved emission spectroscopy (TRES), and the CIE 1931 diagram has been applied to evaluate all possible luminescence colors.     

Polymeric diaqua(μ2‐2,2′‐bipyrimidinyl‐κ4N1,N1′:N3,N3′)‐di‐μ3‐hydroxy‐bis(μ5‐benzene‐1,3,5‐tricarboxylato‐κ5O1:O2:O3:O3:O5)tetracobalt(II) dihydrate

The structure of the title compound, [Co₄(C₉H₃O₆)₂(OH)₂(C₈H₆N₄)(H₂O)₂]·2H₂O, contains three separate species, namely the μ₅‐bridging C₉H₃O₆^3? anion, the doubly chelating and therefore μ₂‐bridging C₈H₆N₄ ligand (bi­pyrimidine, BPM), and the dihydrated di­aqua­di­hydroxy tetranuclear cationic cluster, [Co₄(OH^?)₂(H₂O)₂]⁶⁺·2H₂O, which lies on a crystallographic centre of symmetry, as does the BPM ligand with, in this case, the centre of symmetry coincident with the midpoint of the C—C bond joining the six‐membered rings. Within the cation cluster, the Co atoms of one pair are five‐coordinate and those of the other six‐coordinate.     

Cyclic Voltammetry Study of the Mn‐Substituted Polyoxoanions [MnII4(H2O)2(H4AsW15O56)2]18− and [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17−: Electrodeposition of Manganese Oxides Electrocatalysts for Dioxygen Reduction

The electrochemical behavior of two manganese (Mn)‐substituted polyoxoanions, the dissymmetrical Dawson sandwich‐type [Mn^II₄(H₂O)₂(H₄AsW₁₅O₅₆)₂]^18? and the Keggin sandwich banana‐shaped [((Mn^IIOH₂)Mn^II₂PW₉O₃₄)₂(PW₆O₂₆)]^17? is investigated. At pH 5, the oxidation of the Mn^II‐centers results in one oxidation wave for [Mn^II₄(H₂O)₂(H₄AsW₁₅O₅₆)₂]^18? and two oxidation waves for [((Mn^IIOH₂)Mn^II₂PW₉O₃₄)₂(PW₆O₂₆)]^17?. To the best of our knowledge, presence of the second Mn‐based wave is rarely observed in the electrochemistry of Mn‐containing polyoxometalates. Deposition of Mn‐oxides electrocatalysts for dioxygen reduction is noticed by cyclic voltammetry, which can be distinguished by the significant positive shift in potentials of the dioxygen reduction reaction.     

Topologisch und elektronisch bemerkenswerte „reduzierte”︁ Cluster des Typs [V18O42(X)]n− (X = SO4, VO4) mit Td-Symmetrie und davon abgeleitete Cluster [V(18–p)As2pO42(X)]m− (X = SO3, SO4, H2O; p = 3, 4)

Reduced Clusters with Remarkable Topological and Electronic Properties of the Type of [V₁₈O₄₂(X)]^n? (X = SO₄, VO₄) with T_d-Symmetry and Related Clusters [V_(18—p)As_2pO₄₂(X)]^m? (X = SO₃, SO₄, H₂O; p = 3, 4) The novel cluster-compounds Na₆[V₁₈O₄₂H₉(VO₄)] · 21 H₂O, (NH₄)₈[V₁₈O₄₂(SO₄)] · 25 H₂O, K₆[V₁₅As₆O₄₂(H₂O)] · 8 H₂O, (NH₄)₆[V₁₄As₈O₄₂(SO₃)], (NH₄)₆[V₁₄As₈O₄₂(SO₄)] and [N(CH3)₃]₄[₄V₁₄As₈0₄₂(H₂0)] were prepared and characterized by IR- and UV/Vis/NIR-spectroscopy, magnetic measurements and complete crystal structure analysis. For structural data see Inhaltsübersicht. Topological relations to the rhombicuboctahedron spanned by 24 0-atoms of the genuine hypothetical a-Keggin ion, at which the square planes are capped by V?O or As₂O groups, are discussed. Of particular interest are the ?extended”? Keggin ions [V₁₈O₄₂(X)]ⁿ- (X = SO₄ VO₄), (formaly derived from the hypothetical genuine a-Keggin ion by addition of six V?O groups) which have quite different electron populations in spite of the same structure of their cluster shells.     

Zur Kenntnis von Kaliumarseniten im Dreistoffsystem K2O?As2O3?H2O. Darstellung und Kristallstruktur von K3(HAs2O4)(As2O4) · 3/2 H2O

Concerning Potassium Arsenites in the Three-Component System K₂O? As₂O₃? H₂O. Preparation and Crystal Structure of K₃(HAs₂O₄) (As₂O₄) · 3/2 H₂O The phase K₃(HAs₂O₄)(As₂O₄) · 3/2 H₂O has been identified in the system K₂O? As₂O₃? H₂O at 40°C and characterized by X-ray structural analysis. In the crystal lattice independent polymetaarsenite anions, [HAs₂O₄^?]_n and [As₂O₄^2?]_n, adopt parallel zweier single chains.     

Bis(2‐amino‐1H‐benzimidazol‐3‐ium) tetrakis(μ‐but‐2‐enoato)‐κ4O:O′;κ3O,O′:O;κ3O:O,O′‐bis[bis(but‐2‐enoato‐κ2O,O′)holmium(III)]

The title ionic compound, (C₇H₈N₃)₂[Ho₂(C₄H₅O₂)₈], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2‐amino‐1H‐benzimidazol‐3‐ium (Habim⁺) cations. The asymmetric part of each dimer is made up of one Ho^III cation and four crotonate (crot or but‐2‐enoate) anions, two of them acting in a simple η²‐chelating mode and the remaining two acting in two different μ₂:η² fashions, viz. purely bridging and bridging–chelating. Symmetry‐related Ho^III cations are linked by two Ho—O—Ho and two Ho—O—C—O—Ho bridges which lead to rather short intracationic Ho...Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho₂(crot)₈]²⁻ and Habim⁺ ions are linked by a number of N—H...O hydrogen bonds, in which all N—H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two‐dimensional structures parallel to (110), which are linked to each other by weaker π–π contacts between Habim⁺ benzene groups.     

Synthesis and Crystal Structure of [Cu2(H2O)2(phen)2(OH)2][Cu2(phen)2(OH)2(CO3)2] · 10 H2O with phen = 1,10‐phenanthroline

The blue copper complex [Cu₂(H₂O)₂(phen)₂(OH)₂][Cu₂(phen)₂(OH)₂(CO₃)₂] · 10 H₂O, which was prepared by reaction of 1,10‐phenanthroline monohydrate, CuCl₂ · 2 H₂O and Na₂CO₃ in the presence of succinic acid in CH3OH/H₂O at pH = 13.0, crystallized in the triclinic space group P1 (no. 2) with cell dimensions: a = 9.515(1) Å, b = 12.039(1) Å, c = 12.412(2) Å, α = 70.16(1)°, β = 85.45(1)°, γ = 81.85(1)°, V = 1323.2(2) ų, Z = 1. The crystal structure consists of dinuclear [Cu₂(H₂O)₂(phen)₂(OH)₂]²⁺ complex cations, dinuclear [Cu₂(phen)₂(OH)₂(CO₃)₂]^2– complex anions and hydrogen bonded H₂O molecules. In both the centrosymmetric dinuclear cation and anion, the Cu atoms are coordinated by two N atoms of one phen ligand, three O atoms of two μ‐OH groups and respectively one H₂O molecule or one CO₃^2– anion to complete distorted [CuN₂O₃] square‐pyramids with the H₂O molecule or the CO₃^2– anion at the apical position (equatorial d(Cu–O) = 1.939–1.961 Å, d(Cu–N) = 2.026–2.051 Å and axial d(Cu–O) = 2.194, 2.252 Å). Two adjacent [CuN₂O₃] square pyramids are condensed via two μ‐OH groups. Through the interionic hydrogen bonds, the dinuclear cations and anions are linked into 1D chains with parallel phen ligands on both sides. Interdigitation of phen ligands of neighboring 1D chains generated 2D layers, between which the hydrogen bonded water molecules are sandwiched.     

Pentapotassium dodecatungsto­borate(III) hexadecahydrate

The title compound, K₅[BW₁₂O₄₀]·16H₂O, contains a [BW₁₂O₄₀]^5? polyanion of 222 crystallographic symmetry, with a central tetrahedrally coordinated B^III atom surrounded by four groups of three edge‐sharing octahedra (W₃O₁₃ subunits), which are linked in turn to each other and to the central BO₄ tetrahedron by shared O atoms at the vertices. There is a crystallographically unique B—O bond of 1.554 (10) Å, while the average W—O distances are 2.344 (17) Å for four coordinate O atoms, 1.917 (12) and 1.89 (2) Å for two coordinate O atoms within and connecting the W₃O₁₃ subunits, respectively, and 1.709 (8) Å for terminal O atoms. Not all of the K⁺ ions and H₂O groups were located.     

High-nuclearity Ni-substituted polyoxometalates: a series of poly(polyoxotungstate)s containing 20–22 nickel centers

Three high‐nuclearity Ni‐substituted polyoxotungstates (POTs)—[Ni(enMe)₂(H₂O)₂]₂[Ni(H₂O)₆]₂‐ [Ni(enMe)₂][Ni(H₂O)₂]_1.5[HNi₂₀X₄W₃₄‐ (OH)₄O₁₃₆(H₂O)₆(enMe)₈] ? 11 H₂O ( 3 ), [Ni(en)₂(H₂O)]₂[H₈Ni₂₁X₄W₃₄(OH)₄‐ O₁₃₆(en)₁₀(H₂O)₅] ? 22 H₂O ( 4 ), and [Ni‐(enMe)₂]₂[H₆Ni₂₂X₄W₃₄(OH)₄O₁₃₆(H₂O)₆(enMe)₁₀] ? 18 H₂O ( 5 ), in which en=ethylenediamine, enMe=1,2‐diaminopropane, X=0.5 P+0.5 Ge—were made under hydrothermal conditions and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. The structures of 3 – 5 can be viewed as novel derivatives of [H₆Ni₂₀P₄W₃₄(OH)₄O₁₃₆(enMe)₈‐ (H₂O)₆] ? 12 H ₂O ( 1 ) and [Ni(en)₂‐ (H₂O)]₂[H₈Ni₂₀P₄W₃₄(OH)₄O₁₃₆(en)₉‐ (H₂O)₄] ? 16 H ₂O ( 2 ), which both contain 20 nickel ions per structural unit. Compound 3 is the first example of a 1D cluster chain constructed from Ni₂₀‐substituted polyanions [HNi₂₀X₄‐ W₃₄(OH)₄O₁₃₆(H₂O)₆(enMe)₈]^11? and [Ni(enMe)₂]²⁺ bridges. Compound 4 is a novel cluster–organic chain built by Ni₂₁‐substituted polyanions [H₈Ni₂₁X₄W₃₄(OH)₄O₁₃₆(en)₁₀(H₂O)₅]^4? and en molecule bridges. Compound 5 is a discrete POT with 22 Ni centers, and is not only the largest nickel‐substituted POT, but also contains the highest number of nickel ions in one polyanion to date. Magnetic measurements illustrate that overall ferromagnetic interactions exist in 1 – 5 . The magnetic behavior of 1 and 2 was theoretically simulated by the MAGPACK magnetic program package.     

dl-Serine covalently modified multinuclear lanthanide-implanted arsenotungstates with fast photochromism

A series of dl-serine covalently modified multinuclear lanthanide implanted arsenotungstates K₂[{Ln(H₂O)₇}₂{As₄W₄₄O₁₃₇(OH)₁₈(H₂O)₂(dl-Ser)₂}{Ln₂(H₂O)₅(dl-Ser)}₂]·65H₂O (dl-Ser = dl-serine, Ln = La (1), Ce (2), Pr (3)) are obtained. Crystal structure analysis shows that these compounds are isomorphic and contain the basic [{As₄W₄₄O₁₃₇(OH)₁₈(H₂O)₂(dl-Ser)₂}{Ln₂(H₂O)₅(dl-Ser)}₂]^8– polyoxoanion constituted by two {As₂W₁₉O₅₉(OH)₈(H₂O)}^6? subunits, a [W₆O₂₃(OH)₂(dl-Ser)₂]^14? fragment, and two embedded [Ln₂(H₂O)₅(dl-Ser)]⁵⁺ groups, which further build into one dimensional linear chainlike structure via two peripheral Ln³⁺ ions. Most remarkably, these compounds exhibit rapid photochromic behaviors, which changed color quickly from white (1), yellow (2), green (3) to blue (1), brown (2) and glaucous (3) in ten minutes under UV irradiation, and that the colors gradually recovered in the dark for approximately 22 h.     

Das erste Vanadium(III)‐Borophosphat: Darstellung und Kristallstruktur von CsV3(H2O)2[B2P4O16(OH)4]

The First Vanadium(III) Borophosphate: Synthesis and Crystal Structure of CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] was prepared under mild hydrothermal conditions (T = 165 °C) from mixtures of CsOH_(aq), VCl₃, H₃BO₃, and H₃PO₄ (molar ratio 1 : 1 : 1 : 2). The crystal structure was determined by X‐ray single crystal methods (monoclinic; space group C2/m, No. 12): a = 958.82(15) pm, b = 1840.8(4) pm, c = 503.49(3) pm; β = 110.675(4)°; Z = 2. The anionic partial structure contains oligomeric units [BP₂O₈(OH)₂]^5–, which are built up by a central BO₂(OH)₂ tetrahedron and two PO₄ tetrahedra sharing common corners. V^III is octahedrally coordinated by oxygen of adjacent phosphate tetrahedra and OH groups of borate tetrahedra as well as oxygen of phosphate tetrahedra and H₂O molecules, respectively (coordination octahedra VO₄(OH)₂ and VO₄(H₂O)₂). The oxidation state +3 for vanadium was confirmed by measurements of the magnetic susceptibility. The trimeric borophosphate groups are connected via vanadium centres to form layers with octahedra‐tetrahedra ring systems, which are likewise linked via V^III‐coordination octahedra. Overall, a three‐dimensional framework constructed from VO₄(OH)₂ and VO₄(H₂O)₂ octahedra as well as BO₂(OH)₂ and PO₄ tetrahedra results. The structure contains channels running along [001], which are occupied by Cs⁺ in a distorted octahedral coordination (CsO₄(H₂O)₂).     

Two Heteroleptic Zinc(II) Complexes: [Zn(phen)(C9H15O6)2] and [Zn2(phen)2(H2O)2(C10H16O4)2] · 3H2O

Reactions of a freshly prepared Zn(OH)_2‐2x(CO₃)x · yH₂O precipitate, phenanthroline with azelaic and sebacic acid in CH₃OH/H₂O afforded [Zn(phen)(C₉H₁₅O₄)₂] ( 1 ) and [Zn₂(phen)₂(H₂O)₂(C₁₀H₁₆O₄)₂] · 3H₂O ( 2 ), respectively. They were structurally characterized by X‐ray diffraction methods. Compound 1 consists of complex molecules [Zn(phen)(C₉H₁₅O₄)₂] in which the Zn atoms are tetrahedrally coordinated by two N atoms of one phen ligand and two O atoms of different monodentate hydrogen azelaato groups. Intermolecular C(alkyl)‐H···π interactions and the intermolecular C(aryl)‐H···O and O‐H···O hydrogen bonds are responsible for the supramolecular assembly of the [Zn(phen)(C₉H₁₅O₄)₂] complexes. Compound 2 is built up from crystal H₂O molecules and the centrosymmetric binuclear [Zn₂(phen)₂(H₂O)₂(C₁₀H₁₆O₄)₂] complex, in which two [Zn(phen)(H₂O)]²⁺ moieties are bridged by two sebacato ligands. Through the intermolecular C(alkyl)‐H···O hydrogen bonds and π‐π stacking interactions, the binuclear complex molecules are assembled into layers, between which the lattice H₂O molecules are sandwiched. Crystal data: ( 1 ) C2/c (no. 15), a = 13.887(2), b = 9.790(2), c = 22.887(3)Å, β = 107.05(1)°, U = 2974.8(8)ų, Z = 4; ( 2 ) P1¯ (no. 2), a = 8.414(1), b = 10.679(1), c = 14.076(2)Å, α = 106.52(1)°, β = 91.56(1)°, γ = 99.09(1)°, U = 1193.9(2)ų, Z = 1.     

Di­aqua­tris­(pentane‐2,4‐dionato‐O,O′)­holmium(III) mono­hydrate and di­aqua­tris­(pentane‐2,4‐dionato‐O,O′)holmium(III) 4‐hydroxy­pentan‐2‐one solvate dihydrate

The structures of the title compounds, [Ho(C₅H₇O₂)₃(H₂O)₂]·H₂O and [Ho(C₅H₇O₂)₃(H₂O)₂]·C₅H₈O₂·2H₂O, both show an eight‐coordinate holmium(III) ion in a square antiprismatic configuration. The packing of these structures consists of an infinite two‐dimensional network of hydrogen‐bonded mol­ecules. In both structures, the same hydrogen‐bonded chain of Ho^III complexes is found.     

Bis(5‐hydroxy‐2‐hydroxy­methyl‐4‐pyrone‐κ2O4,O5)bis(2‐hydroxy­methyl‐5‐oxido‐4‐pyrone‐κ2O4,O5)­calcium(II) tetrahydrate

In the title compound, [Ca(C₆H₅O₄)₂(C₆H₆O₄)₂]·4H₂O, which is a kojic acid–Ca²⁺ complex, the Ca atom is on a twofold axis and is octacoordinated by O atoms from four pyrone ligand mol­ecules. The hydroxyl and ketone O atoms of each ligand form a five‐membered chelate ring with the Ca atom. The crystal structure is stabilized by partial stacking and O—H?O hydrogen bonds.