[VO(SeO3)(H2O)2]·0.5H2O

In poly[[diaquaoxido[μ₃‐trioxidoselenato(2−)]vanadium(IV)] hemihydrate], {[VO(SeO₃)(H₂O)₂]·0.5H₂O}_n, the octahedral V(H₂O)₂O₄ and pyramidal SeO₃ building units are linked by V—O—Se bonds to generate ladder‐like chains propagating along the [010] direction. A network of O—H...O hydrogen bonds helps to consolidate the structure. The O atom of the uncoordinated water molecule lies on a crystallographic twofold axis. The title compound has a similar structure to those of the reported phases [VO(OH)(H₂O)(SeO₃)]₄·2H₂O and VO(H₂O)₂(HPO₄)·2H₂O.     

K2[Hg(SO3)2]·2.25H2O

The characteristic feature of the structure of the title compound, dipotassium bis(sulfito‐κS)mercurate(II) 2.25‐hydrate, is a layered arrangement parallel to (001) where each of the two independent [Hg(SO₃)₂]²⁻ anions are grouped into centrosymmetric pairs and are surrounded by two K⁺ cations to give the overall layer composition {K₂[Hg(SO₃)₂]₂}²⁻. The remaining cations and the uncoordinated water molecules are situated between these layers. Within the [Hg(SO₃)₂]²⁻ anions, the central Hg atoms are twofold coordinated by S atoms, with a mean Hg—S bond length of 2.384 (2) Å. The anions are slightly bent [174.26 (3) and 176.99 (3)°] due to intermolecular O...Hg interactions greater than 2.8 Å. All coordination polyhedra around the K⁺ cations are considerably distorted, with coordination numbers ranging from six to nine. Although the H atoms of the five water molecules (one with symmetry 2) could not be located, O...O separations between 2.80 and 2.95 Å suggest a system of medium to weak O—H...O hydrogen bonds which help to consolidate the structural set‐up. Differences and similarities between the bis(sulfito‐κS)mercurate(II) anions in the title compound and those in the related salts (NH₄)₂[Hg(SO₃)₂] and Na₂[Hg(SO₃)₂]·H₂O are discussed.     

Double complexes [Co(NH3)5(H2O)]2[Zr3F18]·6H2O and [Co(NH3)6]2[Zr3F18]·6H2O

The structures of orthorhombic bis[pentaammineaquacobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Ibam), [Co(NH₃)₅(H₂O)]₂[Zr₃F₁₈]·6H₂O, (I), and bis[hexaamminecobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Pnna), [Co(NH₃)₆]₂[Zr₃F₁₈]·6H₂O, (II), consist of complex [Co(NH₃)_x(H₂O)_y]³⁺ cations with either m [in (I)] or and 2 [in (II)] symmetry, [Zr₃F₁₈]⁶⁻ anionic chains located on sites with 222 [in (I)] or 2 [in (II)] symmetry, and water molecules.     

(NH4)4Na2[V10O28]·10H2O

Tetra­ammonium disodium decavanadate decahydrate crystallizes in the triclinic system in space group P. The structure contains typical centrosymmetric OV₆ double octahedra and centrosymmetric pairs of edge‐shared NaO₆ double octahedra forming a layered structure. In contrast to other monovalent cationic decavanadates, the NaO₆ double octahedra are integrated in the layer.     

Darstellung,Ramanspektren und Kristallstrukturen von V2O3(SO4)2, K[VO(SO4)2] und NH4[VO(SO4)2]

Preparation, Raman Spectra, and Crystal Structures of V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] The oxo-sulfato-vanadates(V) V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] have been prepared as crystals suitable for X-ray structure determination. In all structures sulfate acts as an unidentate ligand only toward a single vanadium atom. The structure of V₂O₃(SO₄)₂ consists of a threedimensional network of pairs of cornershared VO₆ octahedra with one terminal oxygen atom each, and SO₄ tetrahedra. All oxygen atoms of the sulfate ions are coordinated. NH₄[VO(SO₄)₂] and K[VO(SO₄)₂] are isostructural. VO₆ octahedra with one terminal oxygen atom and pairs of sulfate tetrahedra form infinite chains by corner sharing. The chains are weakly interlinked to layers. The sulfate ions are distorted towards planar SO₃ molecules and single oxygen atoms attached to vanadium. This structural detail gives an explanation for the mechanism of the reversible reaction K[VO(SO₄)₂] ? K[VO₂(SO₄)] + SO₃ at 400°C. Raman spectra of the compounds have been recorded and interpreted with respect to their structures. Crystal data: V₂O₃(SO₄)₂, monoclinic, space group P2₁/a, a = 947.2(4), b = 891.3(3), c? 989.1(4) pm, β = 104.56(3)°, Z = 4, 878 unique data, R(R_w) = 0.039(0,033); K[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(2), b = 869.6(9), c = 1 627(1)pm, Z = 4, 642 unique data, R(R_w) = 0,11(0,10); NH₄[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(1), b = 870.0(2), c = 1 676.7(4)pm, Z = 4, 768 unique data, R(R_w) = 0.088(0.083).     

A hydrothermal investigation of the 1/2V2O5-H2C2O4/H3PO4/NH4OH system: synthesis and structures of (NH4)VOPO(4).1.5H2O, (NH4)0.5VOPO(4).1.5H2O, (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2](2).3H2O, and (NH4)2[VO(HPO4)]2(C2O4).5H2O

The 1/2V2O5-H2C2O4/H3PO4/NH4OH system was investigated using hydrothermal techniques. Four new phases, (NH4)VOPO(4).1.5H2O (1), (NH4)0.5VOPO(4).1.5H2O (2), (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2.3H2O (3), and (NH4)2[VO(HPO4)]2(C2O4).H2O (4), have been prepared and structurally characterized. Compounds 1 and 2 have layered structures closely related to VOPO(4).2H2O and A0.5VOPO4.yH2O (A = mono- or divalent metals), whereas 3 has a 3D open-framework structure. Compound 4 has a layered structure and contains both oxalate and phosphate anions coordinated to vanadium cations. Crystal data: (NH4)VOPO(4).1.5H2O, tetragonal (I), space group I4/mmm (No. 139), a = 6.3160(5) A, c = 13.540(2) A, Z = 4; (NH4)0.5VOPO(4).1.5H2O, monoclinic, space group P2(1)/m (No. 11), a = 6.9669(6) A, b = 17.663(2) A, c = 8.9304(8) A, beta = 105.347(1) degrees, Z = 8; (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2.3H2O, triclinic, space group P1 (No. 2), a = 10.2523(9) A, b = 12.263(1) A, c = 12.362(1) A, alpha = 69.041(2) degrees, beta = 65.653(2) degrees, gamma = 87.789(2) degrees, Z = 2; (NH4)2[VO(HPO4)]2(C2O4).5H2O, monoclinic (C), space group C2/m (No. 12), a = 17.735(2) A, b = 6.4180(6) A, c = 22.839(2) A, beta = 102.017(2) degrees, Z = 6.     

Crystal Structure of Guanylurea Sulphate Hydrate [H2NC(=O)NHC(NH2)2]2SO4 · 2 H2O

Single crystals of guanylurea (1–carbamoylguanidinium) sulphate hydrate (C 2/c, a = 30.353(6), b = 6.6162(13), c = 21.204(4) Å, β = 99.37(3)°, V = 4201.4(14) ų, T = 200 K) were obtained from a neutral aqueous solution containing guanylurea sulphate. By analogy with previously reported simple molecular guanylurea salts, the title compound builds up an array of mutually linked chains of cations and anions, with the crystal packing being largely controlled by an extensive hydrogen bonding network.     

Electrochemical and Biological Studies on Reactivity of [VO(oda)(H2O)2], [Co(oda)(H2O)2]·H2O,and [Ni(oda)­(H2O)3]·1.5H2O Towards Superoxide Free Radicals

The reactivity of superoxide free radicals (O₂ ^{· –}) generated electrochemically towards the oxydiacetate metal complexes, namely [VO(oda)(H₂O)₂], [Co(oda)(H₂O)₂] · H₂O, and [Ni(oda)(H₂O)₃] · 1.5H₂O (oda = oxydiacetate) was examined by cyclic voltammetry. The measurements were carried out in DMSO solution using a platinum electrode. Based on the height of the anodic peak E_a that corresponds to electrochemical oxidation O₂ ^{· –} → O₂ + e, in the absence and in the presence of the compounds in the mixture, their O₂ ^{· –} scavenge ability was assessed. The influence of the type of the complex was briefly discussed. H₂O₂ was used to induce cellular injury in a mouse hippocampal cell line (HT22). The cytoprotection of chemical compounds was tested at the mitochondrial (MTT test) and plasma membrane level (LDH leakage). Dose‐dependent effect (10 and 100 μM of the complex) of investigated compounds was observed.     

K2[Mo2O4(C2O4)2(H2O)2]·3H2O

The crystal and molecular structure of dipotassium di‐μ‐oxo‐bis[aqua(oxalato‐O¹,O²)oxomolybdenum(III)] trihydrate, K₂­[Mo₂O₄(C₂O₄)₂(H₂O)₂]·3H₂O, has been determined from X‐ray diffraction data. In the dimeric anion, which has approximate twofold symmetry, each Mo atom is in a distorted octahedral coordination, being bonded to one terminal oxo‐O atom, two bridging O atoms, two O atoms from the oxalato ligand and one from the water mol­ecule. Bond lengths trans to the multiple‐bonded terminal oxo ligand are larger than those in the cis position, confirming the trans influence as a generally valid rule.     

Syntheses and Structures of Na2Mg3(OH)2(SO4)3·4H2O and K2Mg3(OH)2(SO4)3·2H2O

The crystal structures of Na₂Mg₃(OH)₂(SO₄)₃ · 4H₂O and K₂Mg₃(OH)₂(SO₄)₃ · 2H₂O, were determined from conventional laboratory X‐ray powder diffraction data. Synthesis and crystal growth were made by mixing alkali metal sulfate, magnesium sulfate hydrate, and magnesium oxide with small amounts of water followed by heating at 150 °C. The compounds crystallize in space group Cmc2₁ (No. 36) with lattice parameters of a = 19.7351(3), b = 7.2228(2), c = 10.0285(2) Å for the sodium and a = 17.9427(2), b = 7.5184(1), c = 9.7945(1) Å for the potassium sample. The crystal structure consists of a linked MgO₆–SO₄ layered network, where the space between the layers is filled with either potassium (K⁺) or Na⁺‐2H₂O units. The potassium‐bearing structure is isostructural to K₂Co₃(OH)₂(SO₄)₃ · 2(H₂O). The sodium compound has a similar crystal structure, where the bigger potassium ion is replaced by sodium ions and twice as many water molecules. Geometry optimization of the hydrogen positions were made with an empirical energy code.     

Darstellung und Kristallstruktur von [Co(NH3)6]2P4O13 · 5 H2O

Preparation and Crystal Structure of [Co(NH₃)₆]₂P₄O₁₃ 7·5H₂O Single crystals of [Co(NH₃)₆]P₄O₁₃ · 5 H₂O were obtained by diffusion controlled growth. To this end sodium polytetraphosphate was prepared by column chromatography and allowed to react with [Co(NH₃)₆]Cl₃. The compound [Co(NH₃)₆]₂P₄O₁₃ · 5 H₂O contains the novel isolated polytetraphosphate anion. The expected systematic variation in bond length in the P? O? P bridges of the poly tetraphosphate anion was verified. The conformation of the anion is discussed.     

Kristallstruktur und schwingungsspektrometrische Daten von cis-Na2[Pd(SO3)2en] · 4 H2O

Crystal Structure and Data from Vibrational Spectra of cis-Na₂[Pd(SO₃)₂en] · 4 H₂O The compound cis-Na₂[Pd(SO₃)₂en] · 4 H₂O (en = 1,2-diaminoethane) crystallizes in the orthorhombic space group Pnma with a = 623.7(2), = 1070.9(10), c = 1989.5(30) pm and Z = 4. In the [Pd(SO₃)₂en]^2? anions the trans-influence of the sulfite ligands manifests itself in long Pd? N bonds with short Pd? S distances. A set of Na⁺ ions is present in face-sharing octahedra Na(OH₂)₆⁺, forming rods [Na(OH₂)_6/2]⁺ parallel to [100]. A second set of Na⁺ ions is surrounded by two H₂O molecules and four O atoms from SO₃ ligands of two anions to form likewise octahedra with face-sharing, yielding rods [Na(OH₂)_2/2{(OSO₂)₂Pd en}_2/2]^? parallel to [100]. Comparatively low v(Pd? N)-frequencies reveal the trans-influence of the sulfite ligands also in the vibrational spectra.     

New Perspectives in Polyoxometalate Chemistry by isolation of compounds containing very large moieties as transferable building blocks: (NMe4)5[As2Mo8V4AsO40] · 3H2O, (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O, (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O,and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O

The compounds (NMe₄)₅[As₂Mo₈V₄AsO₄₀] · 3 H₂O 2a , (NH₄)₂₁[H₃Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 65 H₂O 3a , (NH₂Me₂)₁₈(NH₄)₆[Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 14 H₂O 3b and (NH₄)₁₂[Mo₃₆(NO)₄O₁₀₈(H₂O)₁₆] · 33 H₂O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo₁₇} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na₃(NH₄)₁₂[H₁₅Mo₅₇Fe₆(NO)₆O₁₈₃(H₂O)₁₈] · 76 H₂O 7a .     

(Et4N)4[V4O12]·2H2O

The title compound, tetrakis(tetraethylammonium) cyclo‐tetra‐μ‐oxo‐tetrakis[dioxovanadium(V)] dihydrate, (C₈H₂₀N)₄[V₄O₁₂]·2H₂O, was obtained by reacting V₂O₅ with (C₂H₅)₄NOH. It consists of a discrete centrosymmetric molecular anion, [V₄O₁₂]^4?, where four tetrahedral VO₄ units share two vertices with each other to form a ring. A water mol­ecule is attached on each side of the ring through hydrogen bonds.     

Ca[Ag2(SCN)4]·2H2O

Calcium tetra­thio­cyanato­diargentate(I) dihydrate, Ca[Ag₂(SCN)₄]·2H₂O, contains eight‐membered Ag₄S₄ rings bonded together through shared atoms to form layers parallel to (100). The thio­cyanate groups link the layers to Ca–O chains running parallel to the c axis. The Ca atom is located on a twofold rotation axis parallel to b and is surrounded by four water molecules of crystallization and four thio­cyanate N atoms in a distorted square antiprism.     

Thermal behaviour of [CoCO3(NH3)4]2SO4 · 3H2O

The thermal behaviour of [CoCO₃(NH₃)₄]₂SO₄ · 3H₂O was studied using X-ray diffraction diagrams, DTA, TG and heating at constant temperatures for different periods of time. The X-ray study was made in order to characterize with the powder diagrams the phases obtained and to follow the reactions of the complex when heated in air up to 800. A parallel infrared spectral study was also made. The results obtained by the various experimental methods were compared with the theoretical weight losses.

---

Zusammenfassung Das thermische Verhalten von [CoCO₃(NH₃)₄]₂SO₄ · 3H₂O wurde durch Röntgendiffraktion, DTA, TG und Erhitzen auf gleiche Temperatur in verschiedenen Zeiten, untersucht. Die röntgenographische Prüfung diente zum Kennzeichnen der erhaltenen Phasen durch Pulverdiagramme und zur Verfolgung der in Luft bis 800 im Komplex verlaufenden Reaktionen. Es wurde parallel auch eine Prüfung durch infrarote Spektroskopie unternommen. Die auf verschiedene Weise erhaltenen Ergebnisse wurden miteinander in Einklang gebracht.

---

Résumé On a étudié le comportement thermique de [CoCO₃(NH₃)₄]₂SO₄ · 3H₂O par diffraction de rayons X, ATD et ATG avec maintien en thermostat. L'étude par rayons X a été menée dans le but de caractériser les phases obtenues par leur diagramme de poudre et de suivre les réactions données par le complexe chauffé dans l'air jusqu'à 800. En raison de l'impossibilité de suivre l'évolution thermique par rayons X, une étude parallèle a été effectuée par spectrographie infrarouge. On a essayé de rapprocher les résultats obtenus à l'aide de ces différentes méthodes.

---

[CoCo₃(NH₃)₄]₂SO₄·3H₂O , , , . 800. . , , , .

---

---

This work has been carried out, in part, through the Ayuda para el Fomento de la Investigación en la Universidad.     

A new hydrated ammonium hydroxy­borate, (NH4)2[B10O14(OH)4]·H2O

The structure of a new synthetic compound, di­ammonium tetra­hydroxy­deca­borate monohydrate, has been determined by single‐crystal X‐ray diffraction. It crystallizes in triclinic space group and all atoms occupy general sites. The title compound is composed of [B₁₀O₁₅(OH)₄]⁴⁻ ions as the fundamental building blocks, and these are linked end‐to‐end by sharing two common O atoms, thus producing infinite chains of composition [B₁₀O₁₄(OH)₄]_n^2n–. These chains are linked by hydrogen bonds, thus forming borate sheets. Water mol­ecules and ammonium ions between these sheets connect adjacent sheets via hydrogen bonds.     

New coordination modes in potassium edta salts: K2[H2edta]·2H2O,K3[Hedta]·2H2O and K4[edta]·3.92H2O

Three potassium edta (edta is ethylenediaminetetraacetic acid, H₄Y) salts which have different degrees of ionization of the edta anion, namely dipotassium 2‐({2‐[bis(carboxylatomethyl)azaniumyl]ethyl}(carboxylatomethyl)azaniumyl)acetate dihydrate, 2K⁺·C₁₀H₁₄N₂O₈²⁻·2H₂O, (I), tripotassium 2,2′‐({2‐[bis(carboxylatomethyl)amino]ethyl}ammonio)diacetate dihydrate, 3K⁺·C₁₀H₁₃N₂O₈³⁻·2H₂O, (II), and tetrapotassium 2,2′,2′′,2′′′‐(ethane‐1,2‐diyldinitrilo)tetraacetate 3.92‐hydrate, 4K⁺·C₁₀H₁₂N₂O₈⁴⁻·3.92H₂O, (III), were obtained in crystalline form from water solutions after mixing edta with potassium hydroxide in different molar ratios. In (II), a new mode of coordination of the edta anion to the metal is observed. The HY³⁻ anion contains one deprotonated N atom coordinated to K⁺ and the second N atom is involved in intramolecular bifurcated N—H...O and N—H...N hydrogen bonds. The overall conformation of the HY³⁻ anions is very similar to that of the Y⁴⁻ anions in (III), although a slightly different spatial arrangement of the –CH₂COO⁻ groups in relation to (III) is observed, whereas the H₂Y²⁻ anions in (I) adopt a distinctly different geometry. The preferred synclinal conformation of the –NCH₂CH₂N– moiety was found for all edta anions. In all three crystals, the anions and water molecules are arranged in three‐dimensional networks linked via O—H...O and C—H...O [and N—H...O in (I) and (II)] hydrogen bonds. K...O interactions also contribute to the three‐dimensional polymeric architecture of the salts.