Mechanochemical Synthesis and Characterization of Hydrated and Dehydrated Crystalline Strontium Terephtalates

A successful mechanochemical synthesis of strontium terephthalate trihydrate is described for the first time. The dehydration of Sr(C₈H₄O₄) · 3H₂O occurs at about 100 °C and results in a well‐defined strontium terephtalate, Sr(C₈H₄O₄), thermally stable up to 550 °C. Both compounds are not described so far in the literature. Their structures were solved by ab initio structure determination and subsequent Rietveld refinement of the powder diffraction data. Further methods like DTA‐TG, MAS NMR and FT‐IR spectroscopy, and BET measurements were used to characterize these compounds.     

Die Clusterazide M2[Nb6Cl12(N3)6]·(H2O)4—x (M = Ca,Sr, Ba)

The Cluster Azides M₂[Nb₆Cl₁₂(N₃)₆]·(H₂O)_4—x (M = Ca, Sr, Ba) The isotypic cluster compounds M₂[Nb₆Cl₁₂(N₃)₆] · (H₂O)_4—x (M = Ca (1) , M = Sr (2) and M = Ba (3) ) have been synthesized by the reaction of an aequeous solution of Nb₆Cl₁₄ with M(N₃)₂. 1 , 2 and 3 crystallize in the space group Fd3¯ (No. 227) with the lattice constants a = 1990.03(23), 2015.60(12) and 2043, 64(11) pm, respectively. All compounds contain isolated 16e— clusters whose terminal positions are all occupied by orientationally disordered azide ligands.     

Hybrid Inorganic‐Organic Frameworks: Synthesis and Crystal Structures of RbFe(SO4)(C2O4)0.5·H2O and CsM(SO4)(C2O4)0.5·H2O (M = Mn,Fe)

Three new alkali metal transition metal sulfate‐oxalates, RbFe(SO₄)(C₂O₄)_0.5 · H₂O and CsM(SO₄)(C₂O₄)_0.5 · H₂O (M = Mn, Fe) were prepared through hydrothermal reactions and characterized by single‐crystal X‐ray diffraction, solid state UV/Vis/NIR diffuse reflectance spectroscopy, infrared spectra, thermogravimetric analysis, and powder X‐ray diffraction. The title compounds all crystallize in the monoclinic space group P2₁/c (no. 14) with lattice parameters: a = 7.9193(5), b = 9.4907(6), c = 8.8090(6) Å, β = 95.180(2)°, Z = 4 for RbFe(SO₄)(C₂O₄)_0.5 · H₂O; a = 8.0654(11), b = 9.6103(13), c = 9.2189(13) Å, β = 94.564(4)°, Z = 4 for CsMn(SO₄)(C₂O₄)_0.5 · H₂O; and a = 7.9377(3), b = 9.5757(4), c = 9.1474(4) Å, β = 96.1040(10)°, Z = 4 for CsFe(SO₄)(C₂O₄)_0.5 · H₂O. All compounds exhibit three‐dimensional frameworks composed of [MO₆] octahedra, [SO₄]^2– tetrahedra, and [C₂O₄]^2– anions. The alkali cations are located in one‐dimensional tunnels.     

Crystal structures of calcium and barium oxalato(ethylenediamine-N,N′-diacetato)× chromates(III) M[Cr(Edda)(C2O4)]2·5H2O (M = Ca, Ba)

The crystal structure of Ca[Cr(Edda)(C₂O₄)]₂·5H₂O and Ba[Cr(Edda)(C₂O₄)]₂·5H₂O (H₂Edda — ethylenediamine-N,N′-diacetic acid) was determined by X-ray diffraction analysis. The nearest environment of alkaline earth ions consists of the oxygen atoms of the neighboring [Cr(Edda)(C₂O₄)]^? complex ions (five for Ca and four for Ba) and the water molecules that complete the coordination number to eight. Two atoms and two complex ions are linked into a ring; each Ca atom in the ring is bonded by the oxalate ion bridge to another anion. This results in a centrosymmetric hexanuclear supramolecular assembly. The atoms and the complex anions alternate to form an infinite chain, in which each Ba atom is additionally linked via the oxalate ion bridge with one anion.     

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.     

Bariumstannat‐Pulver durch hydrothermale Synthese und durch Thermolyse von Bariumzinn(IV)‐glykolaten. Synthese und Struktur von [Ba(C2H6O2)4][Sn(C2H4O2)3] und [Ba(C2H6O2)2][Sn(C2H4O2)3]·CH3OH

Barium Stannate Powders from Hydrothermal Synthesis and by Thermolysis of Barium‐Tin(IV)‐Glycolates. Synthesis and Structure of [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] and [Ba(C₂H₆O₂)₂][Sn(C₂H₄O₂)₃]·CH₃OH The hydrothermal reaction as well as the microwave assisted hydrothermal reaction of SnO₂·aq with barium hydroxide gives Ba[Sn(OH)₆] ( 1 ) as powder with bar like particles. Compound 1 of the same morphology can also be isolated from a hydrothermal reaction of [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] ( 3 ). The reaction of SnO₂·aq with Ba(OH)₂·8H₂O in ethylene glycol yields the glycolate [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] ( 3 ), which forms in methanol the solvate [Ba(C₂H₆O₂)₂][Sn(C₂H₄O₂)₃]·CH₃OH ( 4 ). Compounds 1 , 3 and 4 react at different temperatures to BaSnO₃ ( 2 ) consisting of powders with different morphologies; because of the grain size of the resulting powders compounds 3 and 4 are suitable as precursor for the fabrication of corresponding ceramics.     

Thermal dehydration and decomposition of M[M(C2O4)2]·xH2O (x=3 forM=Sr(II) andx=6 forM=Hg(II))

Strontium(II) bis (oxalato) strontium(II) trihydrate, Sr[Sr(C₂O₄)₂]·3H₂O and mercury(II) bis (oxalato) mercurate(II) hexahydrate, Hg[Hg(C₂O₄)₂]·6H₂O have been synthesized and characterized by elemental analysis, reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG and DTA) in air showed SrCO₃ was formed at ca. 500°C through the formation of transient intermediate of a mixture of SrCO₃ and SrC₂O₄ around 455°C. Sharp phase transition from γ-SrCO₃ to β-SrCO₃ indicated by a distinct endothermic peak at 900°C in DTA. Mercury(II) bis (oxalato) mercurate(II) hexahydrate showed an inclined slope followed by surprisingly steep slope in TG at 178°C and finally 98.66% of weight loss at 300°C. The activation energies (E ^*) of the dehydration and decomposition steps have been calculated by Freeman and Carroll and Flynn and Wall's method and compared with the values found by DSC in nitrogen. A tentative reaction mechanism for the thermal decomposition of Sr[Sr(C₂O₄)₂]·3H₂O has been proposed.     

The Ring Acid,H6P6O12 and Ring Acid,H4P4O10 and Their Salts

Abstract

The hydrated salts of the acid H₆P₆O₁₂, Rb₆P₆O·aq and M₃P₆O₁₂·aq (M = Ca, Sr, Ba), that have so far been unknown, have been prepared and studied by X-ray methods, thermal analysis and molecular spectroscopy. It has been found that the anion structure exhibits a chair form with the D_3d symmetry. All the salts are stable at laboratory temperature and are completely decomposed on prolonged heating to 80°C prior to complete dehydration. The newly prepared salts of the acid H₄P₄O₁₀ involve Cs₄P₄0₁₀·1.5 H₂O, Tl₄P₄O₁₀, M₂P₄O₁₀·x H₂O (M = Cu, Ni, Co; x = 10, 2, 6, respectively), Na₂MP₄O₁₀·x H₂O (M = Cu, Ni, Co; x = 8, 8, 4, respectively). They have been studied using X-ray methods, thermal analysis, molecular and reflectance spectra and the magnetic susceptibility. The dehydration of the salts starts at 30 to 40°C and ends by complete decomposition before the completion of dehydration at 150°C. The anion structure for the salt CS₄P₄O₁₀ in the crystalline state has a chair form with C₂ symmetry. However, the anion structure in aqueous solutions approaches a planar arrangement with the D_2h symmetry.     

Kristallstrukturen des Sr(BrO3)2 · H2O,Ba(BrO3)2 · H2O,Ba(IO3)2 · H2O,Pb(CIO3)2 · H2O und Pb(BrO3)2 · H2O

Crystal Structure of Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O The crystall structures of the isostructural halates Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O were determined using X-ray single crystal data (monoclinic space group C2/c? C, Z = 4), The mean bond lengths and bond angles of the halate ions in the Ba(ClO₃)₂ · 1 H₂O-type compounds, which correspond to those of other halates, are Cl? O, 149.0, Br? O, 165.9, I? O, 180.2 pm, ClO₃^?, 106.4, BrO₃^?, 104.0, and IO₃^?, 99.6°. The structure data obtained are discussed in terms of possible orientational disorder of the water molecules, strengths of the hydrogen bonds, influence of the lead ions on the structure, and site group distortion of the halate ions.     

Alkaline earth metal salts of 1‐naphthoic acid

The structures of the Mg, Ca, Sr and Ba salts of 1‐naphthoic acid are examined and compared with analogous structures of salts of benzoate derivatives. It is shown that catena‐poly[[[diaquabis(1‐naphthoato‐κO)magnesium(II)]‐μ‐aqua] dihydrate], {[Mg(C₁₁H₇O₂)₂(H₂O)₃]·2H₂O}_n, exists as a one‐dimensional coordination polymer that propagates only through Mg—OH₂—Mg interactions along the crystallographic b direction. In contrast with related benzoate salts, the naphthalene systems are large enough to prevent inorganic chain‐to‐chain interactions, and thus species with inorganic channels rather than layers are formed. The Ca, Sr and Ba salts all have metal centres that lie on a twofold axis (Z′ = ) and all have the common name catena‐poly[[diaquametal(II)]‐bis(μ‐1‐naphthoato)‐κ³O,O′:O;κ³O:O,O′], [M(C₁₁H₇O₂)₂(H₂O)₂]_n, where M = Ca, Sr or Ba. The Ca and Sr salts are essentially isostructural, and all three species form one‐dimensional coordination polymers through a carboxylate group that forms three M—O bonds. The polymeric chains propagate via c‐glide planes and through MOMO four‐membered rings. Again, inorganic channel structures are formed rather than layered structures, and the three structures are similar to those found for Ca and Sr salicylates and other substituted benzoates.     

Transition Metal Complexes Containing Dihydrogen Hypodiphosphate in Eclipsed Conformation as Ligand: Preparation,Crystal Structure,Vibrational Spectra,and Thermal Behavior of K2[M(H2P2O6)2(H2O)2]·H2O (M = Co,Ni, Cu,and Zn)

The transition metal dihydrogen hypodiphosphate hydrates K₂[Co(H₂P₂O₆)₂(H₂O)₂] · H₂O ( 1 ), K₂[Ni(H₂P₂O₆)₂(H₂O)₂] · H₂O ( 2 ), K₂[Cu(H₂P₂O₆)₂(H₂O)₂] · H₂O ( 3 ) and K₂[Zn(H₂P₂O₆)₂(H₂O)₂] · H₂O ( 4 ) were synthesized and characterized by single crystal structure determination. The compounds 1 – 4 crystallize isotypic in the monoclinic space group C2/m (no. 12) with two formula units in the unit cell. The crystal structure is built up by [H₂P₂O₆]^2– units in an eclipsed conformation, by the corresponding transition metal, potassium cations, and water molecules. The eclipsed conformation of the [H₂P₂O₆]^2– has not been previously observed in none of known hypodiphosphates(IV) analyzed via X‐ray diffraction. However, its proposed based on spectroscopic methods. FT‐IR/FIR and FT‐Raman spectra of the crystalline salts were recorded and the thermal behavior of the compounds was investigated.     

Crystal Structures of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O

Reactions of 1,10‐phenanthroline monohydrate, Na₂C₄H₄O₄ · 6 H₂O and MnSO₄ · H₂O in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] · 2 H₂O ( 1 ) and [Mn(phen)₂(H₂O)₂][Mn(phen)₂(C₄H₄O₄)](C₄H₄O₄) · 7 H₂O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) ų, Z = 1) consists of the dinuclear [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] molecules and hydrogen bonded H₂O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H₂O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) ų, Z = 2) is composed of the [Mn(phen)₂(H₂O)₂]²⁺ cations, [Mn(phen)₂(C₄H₄O₄)] complex molecules, (C₄H₄O₄)^2– anions, and H₂O molecules. The (C₄H₄O₄)^2– anions and H₂O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.     

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.     

Synthesis, Characterization and Thermal Decomposition of M1[M2(C2O4)2]xH2O (x=5 for M1=Co and x=4 for M1=Cd; M2=Ni)

Cobalt bis(oxalato)nickelate pentahydrate, Co[Ni(C₂O₄)₂]5H₂O and cadmium bis(oxalato)nickelate tetrahydrate, Cd[Ni(C₂O₄)2]4H₂O have been synthesized and characterized by elemental analysis, reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG and DTA ) in air showed that both the compound of cobalt and cadmium produced the oxide, MNiO_x (x=3 for M=Co; x=2 for M=Cd ) at 325 and 360°C respectively. DSC studies in nitrogen attributed only the mixture of both the metal at the end. This revised version was published online in July 2006 with corrections to the Cover Date.     

The isotypic hydrogen phosphate and arsenate dihydrates M2HXO4·2H2O (M = Rb,Cs; X = P,As)

The four isotypic alkaline metal monohydrogen arsenate(V) and phosphate(V) dihydrates M₂HXO₄·2H₂O (M = Rb, Cs; X = P, As) [namely dicaesium monohydrogen arsenate(V) dihydrate, Cs₂HAsO₄·2H₂O, dicaesium monohydrogen phosphate(V) dihydrate, Cs₂HPO₄·2H₂O, dirubidium monohydrogen arsenate(V) dihydrate, Rb₂HAsO₄·2H₂O, and dirubidium monohydrogen phosphate(V) dihydrate, Rb₂HPO₄·2H₂O] were synthesized by reaction of an aqueous H₃XO₄ solution with one equivalent of aqueous M₂CO₃. Their crystal structures are made up of undulating chains extending along [001] of tetrahedral [XO₃(OH)]⁻ anions connected via strong O—H...O hydrogen bonds. These chains are in turn connected into a three‐dimensional network via medium‐strength hydrogen bonding involving the water molecules. Two crystallographically different M⁺ cations are located in channels running along [001] or in the free space of the [XO₃(OH)]⁻ chains, respectively. They are coordinated by eight and twelve O atoms forming irregular polyhedra. The structures possess pseudosymmetry. Due to the ordering of the protons in the [XO₃(OH)]⁻ chains in the actual structures, the symmetry is reduced from C2/c to P2₁/c. Nevertheless, the deviation from C2/c symmetry is minute.     

Etude des systemes CaHPO4−MHPO4−H2O (M=Sr,Ba) A 50°C

The systems CaHPO₄−MHPO₄−H₂O (M=Sr, Ba) were studied at 50°C. ForM=Sr, the series of single phases, Ca_1−xSr_xHPO₄ for 0.95<X<0.75 and Ca_xSr_1−xHPO₄ for 0.4<X<1 have been prepared. These solid solution were caracterized by their infrared spectra and their crystallographic unit cell parameters. ForM=Ba a new phase Ca₂Ba(HPO₄)₃ has been determined. It was characterized by DRX, IR, ATD and chemical analyses.

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Zusammenfassung Bei 50°C wurde das System CaHPO₄−MHPO₄−H₂O (mitM=Sr, Ba) untersucht. FürM=Sr wurden Serien von Einzelphasen erhalten: Ca_1−xSr_xHPO₄ für 0.95<X< 0.75 und Ca_xSr_1−xHPO₄ für 0.4<X<1. Diese Mischkristalle wurden anhand ihrer Infrarotspektren und ihrer kristallographischen Elementarzellenparameter charakterisiert. FürM=Ba wurde die neue Phase Ca₂Ba(HPO₄)₃ ermittelt. Sie wurde mittels DRX, IR, ATD und chemischer Analyse charakterisiert.

     

Disulfonated azo dyes: metal coordination and ion‐pair separation in twelve MII compounds of Ponceau Xylidine and Crystal Scarlet

The structures of seven divalent metal cation compounds of Ponceau Xylidine {PX; systematic name of dication: 4‐[2‐(3,4‐dimethylphenyl)hydrazin‐1‐ylidene]‐3‐oxo‐3,4‐dihydronaphthalene‐2,7‐disulfonate}, also known as Acid Red 26, CI 16150, and of five divalent metal cation compounds of Crystal Scarlet {CS; systematic name of dication: 8‐[2‐(naphthalen‐1‐yl)hydrazin‐1‐ylidene]‐7‐oxo‐7,8‐dihydronaphthalene‐1,3‐disulfonate}, also known as Acid Red 44, CI 16250, are presented. These are hexaaquamagnesium(II) PX dimethylformamide (DMF) monosolvate, [Mg(H₂O)₆](C₁₈H₁₄N₂O₇S₂)·C₃H₇NO, (I); heptaaquacalcium(II) PX 2.5‐hydrate, [Ca(H₂O)₇](C₁₈H₁₄N₂O₇S₂)·2.5H₂O, (II); catena‐poly[aqua(μ‐DMF)tris(DMF)bis(μ₃‐PX)distrontium(II)], [Sr(C₁₈H₁₄N₂O₇S₂)(C₃H₇NO)₂(H₂O)_0.5]_n, (III); the transition‐metal series hexaaquametal(II) PX DMF monosolvate, [M(H₂O)₆](C₁₈H₁₄N₂O₇S₂)·C₃H₇NO, where M (metal) = Co, (IV), Ni, (V), Cu, (VI), and Zn, (VII); heptaaquacalcium(II) CS monohydrate, [Ca(H₂O)₇](C₂₀H₁₃N₂O₇S₂)·H₂O, (VIII); octaaquastrontium(II) CS monohydrate, [Sr(H₂O)₈](C₂₀H₁₃N₂O₇S₂)·H₂O, (IX); catena‐poly[[triaqua(DMF)barium(II)]‐μ‐CS], [Ba(C₂₀H₁₃N₂O₇S₂)(C₃H₇NO)(H₂O)₃]_n, (X); tetrakis(DMF)(CS)copper(II) monohydrate, [Cu(C₂₀H₁₃N₂O₇S₂)(C₃H₇NO)₄]·H₂O, (XI); and catena‐poly[[[aquatris(DMF)zinc(III)]‐μ‐CS] diethyl ether hemisolvate], {[Zn(C₂₀H₁₃N₂O₇S₂)(C₃H₇NO)₃(H₂O)]·0.5C₄H₁₀O}_n, (XII). In all cases, the structures obtained were solvates with dimethylformamide (DMF) and/or water present. The disulfonated naphthalene‐based azo anions adopt hydrazone tautomeric forms. The structures of the Mg salt and of four transition‐metal forms (M = Co, Ni, Cu and Zn) of PX are found to form an isostructural series. All have solvent‐separated ion‐pair (SSIP) type structures and the formula [M(H₂O)₆][PX]·DMF. The Ca salt of PX also has an SSIP structure, but has a higher hydration state, [Ca(H₂O)₇][PX]·2.5H₂O. In contrast, the Sr salt of PX, [Sr(PX)(DMF)₂(H₂O)_0.5]_n forms a one‐dimensional coordination polymer. Both the Ca and the Sr salt of CS have an SSIP structure, namely [Ca(H₂O)₇][CS]·H₂O and [Sr(H₂O)₈][CS]·H₂O, whilst the heavier Ba analogue, [Ba(CS)(DMF)(H₂O)₃]_n, forms a one‐dimensional coordination polymer. Unlike PX, two CS structures containing transition metals are found to be coordination complexes, [Cu(CS)(DMF)₄]·H₂O and {[Zn(CS)(DMF)₃(H₂O)]·0.5Et₂O}_n. This suggests that CS is a better ligand than PX for transition metals. The Cu complex forms discrete molecules with Cu in a square‐pyramidal environment, whilst the Zn species is a one‐dimensional coordination polymer based on octahedral Zn centres.     

Tetranuclear Complexes with {M4O4} (M = CoII,NiII) Cubane‐Like Core: Synthesis,Crystal Structure,and Magnetic Properties

Two tetranuclear clusters of formula [M₄L₄(HOMe)₄] {H₂L = (E)‐1‐[(2‐(hydroxymethyl)phenylimino)methyl]naphthalen‐2‐ol} [M = Co ( 1 ), Ni ( 2 )] were hydrothermally synthesized by reaction of M(OAc)₂ · 4H₂O with H₂L and NaOH in MeOH. X‐ray crystal structure analysis revealed that complexes 1 and 2 are isostructural. In the core of the structures, four M^II ions and four oxygen atoms occupied alternate vertices of [M₄O₄] cubane. The magnetic property measurements of 1 and 2 revealed that overall ferromagnetic M^II ··· M^II exchange interactions exist in both complexes.     

Einfach und doppelt deprotonierte Maleinsäure in Praseodym‐hydrogenmaleat‐octahydrat,Pr(C4O4H3)3 · 8 H2O,und Praseodym‐maleatchlorid‐tetrahydrat,Pr(C4O4H2)Cl · 4 H2O

Single and Double Deprotonated Maleic Acid in Praseodymium Hydrogenmaleate Octahydrate, Pr(C₄O₄H₃)₃ · 8 H₂O, and Praseodymiummaleatechloride Tetrahydrate, Pr(C₄O₄H₂)Cl · 4 H₂O Single crystals of Pr(C₄O₄H₃)₃ · 8 H₂O grew by slow evaporation of a solution which had been obtained by dissolving Pr(OH)₃ in aqueous maleic acid. The triclinic compound (P1, Z = 2, a = 728.63(3), b = 1040.23(3), c = 1676.05(8) pm, α = 72.108(2)°, β = 87.774(2)°, γ = 70.851(2)°, R_all = 0.0261) contains Pr³⁺ ions in ninefold coordination of oxygen atoms which belong to two monodentate maleate ions and seven H₂O molecules. There is one further non‐coordinating maleate ion and one crystal water molecule in the unit cell. Thermal treatment of Pr(C₄O₄H₃)₃ · 8 H₂O leads first to the anhydrous compound which then decomposes to the respective oxide in two steps upon further heating. Evaporation of a solution of Pr(C₄O₄H₃)₃ · 8 H₂O which contained additional Cl^– ions yielded single crystals of Pr(C₄O₄H₂)Cl · 4 H₂O. In the crystal structure (monoclinic, P2₁/c, Z = 4, a = 866.0(1), b = 1344.3(1), c = 896.9(1) pm, β = 94.48(2)°, R_all = 0.0227), the Pr³⁺ ions are surrounded by nine oxygen atoms. The latter belong to four H₂O molecules and three maleate ions. Two of the latter act as bidentate ligands.     

Imidazole Coordinated Sandwich‐type Antimony Poly‐oxotungstates Na9[{Na(H2O)2}3{M(C3H4N2)}3(SbW9O33)2]·xH2O (M=NiII,CoII, ZnII,MnII)

The imidazole covalently coordinated sandwich‐type heteropolytungstates Na₉[{Na(H₂O)₂}₃{M(C₃H₄N₂)}₃‐ (SbW₉O₃₃)₂]·xH₂O (M=Ni^II, x=32; M=Co^II, x=32; M=Zn^II, x=33; M=Mn^II, x=34) were obtained by the reaction of Na₂WO₄·2H₂O, SbCl₃·6H₂O, NiCl₂·6H₂O [MnSO₄·H₂O, Co(NO₃)₂·6H₂O, ZnSO₄·7H₂O] and imidazole at pH≈7.5. The structure of Na₉[{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂]·32H₂O was determined by single crystal X‐ray diffraction. Polyanion [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂}₃]^9? has approximate C_3v symmetry, imidazole coordinated six‐nuclear cluster [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃]⁹⁺ is encapsulated between two (α‐SbW₉O₃₃)^9?, the three rings of imidazole in the polyanion are perpendicular to the horizontal plane formed by six metals (Na‐Ni‐Na‐Ni‐Na‐Ni) in the central belt, and π‐stacking interactions exist between imidazoles of neighboring polyanions with dihedral angel of 60°. The compounds were also characterized by IR, UV‐Vis spectra, TG and DSC, and the thermal decomposition mechanism of the four compounds was suggested by TG curves.