Hydrothermal Synthesis and Crystal Structures of Na2Be3(SeO3)4·H2O and Cs2[Mg(H2O)6]3(SeO3)4

The selenites, Na₂Be₃(SeO₃)₄ · H₂O and Cs₂[Mg(H₂O)₆]₃(SeO₃)₄, were synthesized under hydrothermal conditions. The crystal structures of Na₂Be₃(SeO₃)₄ · H₂O and Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ were determined by single‐crystal X‐ray diffractions. Na₂Be₃(SeO₃)₄ · H₂O crystallizes in the triclinic space group P1 (no. 2) with unit cell parameters a = 4.8493(9), b = 12.013(2), c = 12.077(2) Å, and Z = 2, whereas Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ crystallizes in the monoclinic space group C2/m (no. 12) with lattice cell parameters a = 12.596(6), b = 7.297(4), c = 16.914(8) Å, and Z = 2. Na₂Be₃(SeO₃)₄ · H₂O features a three‐dimensional open framework structure formed by BeO₄ tetrahedra and SeO₃ trigonal pyramids. Na cations and H₂O molecules are located in different tunnels. Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ has a structure composed of isolated [Mg(H₂O)₆] octahedra and SeO₃ trigonal pyramids interacted by hydrogen bonds, and Cs cations are resided in‐between. Both compounds were characterized by thermogravimetric analysis and FT‐IR spectroscopy.     

Structural Diversity of Sheets in Rubidium Uranyl Oxoselenates: Synthesis and Crystal Structures of Rb2[(UO2)(SeO4)2(H2O)](H2O), Rb2[(UO2)2(SeO4)3(H2O)2](H2O)4, and Rb4[(UO2)3(SeO4)5(H2O)]

Single crystals of three rubidium uranyl selenates, Rb₂[(UO₂)(SeO₄)₂(H₂O)](H₂O) ( 1 ), Rb₂[(UO₂)₂(SeO₄)₃(H₂O)₂](H₂O)₄ ( 2 ), and Rb₄[(UO₂)₃(SeO₄)₅(H₂O)] ( 3 ), have been prepared by evaporation from aqueous solutions made out of mixtures of uranyl nitrate, selenic acid and Rb₂CO₃. The structures of all compounds have been solved by direct methods on the basis of X‐ray diffraction data sets. The crystallographic data are as follows: ( 1 ): orthorhombic, Pna2₁, a = 13.677(2), b = 11.8707(13), c = 7.6397(9) Å, V = 1240.4(3) ų, R₁ = 0.045 for 2396 independent observed reflections; ( 2 ): triclinic, P1¯, a = 8.4261(12), b = 11.8636(15), c = 13.3279(18) Å, α = 102.612(10), β = 107.250(10), γ = 102.510(10)°, V = 1183.7(3) ų, R₁ = 0.067 for 4762 independent observed reflections; ( 3 ): orthorhombic, Pbnm, a = 11.3761(14), b = 15.069(2), c = 19.2089(17) Å, V = 3292.9(7) ų, R₁ = 0.075 for 3808 independent observed reflections. The structures of the phases 1 , 2 , and 3 are based upon uranyl selenate hydrate sheets composed from corner‐sharing pentagonal [UO₇]^8— bipyramids and [SeO₄]^2— tetrahedra. In the crystal structure of 1 , the sheets have composition [(UO₂)(SeO₄)₂(H₂O)]^2— and run parallel to (001). The interlayer contains Rb⁺ cations and additional H₂O molecules. In structure of 2 , the [(UO₂)₂(SeO₄)₃(H₂O)₂]^2— sheets are oriented parallel to (101). Highly disordered Rb⁺ cations and H₂O molecules are located between the sheets. The structure of 3 is based upon [(UO₂)₃(SeO₄)₅(H₂O)]^4— sheets stacked parallel to (010) and contains Rb⁺ cations in the interlayers. The topologies of the uranyl oxoselenate sheets observed in the structures of 1 , 2 , and 3 are related to the same simple and highly‐symmetric graph consisting of 3‐connected white and 6‐connected black vertices.     

Crystal Structures of [Cu2(bpy)2(H2O)(OH)2(SO4)]·4H2O and [Cu(bpy)(H2O)2]SO4 with bpy = 2, 2′‐Bipyridine

Two sulfato Cu^II complexes [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)]· 4H₂O ( 1 ) and [Cu(bpy)(H₂O)₂]SO₄ ( 2 ) were synthesized and structurally characterized by single crystal X—ray diffraction. Complex 1 consists of the asymmetric dinuclear [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)] complex molecules and hydrogen bonded H₂O molecules. Within the dinuclear molecules, the Cu atoms are in square pyramidal geometries, where the equatorial sites are occupied by two N atoms of one bpy ligand and two O atoms of different μ₂—OH groups and the apical position by one aqua ligand or one sulfato group. Through intermolecular O—H···O and C—H···O hydrogen bonds and intermolecular π—π stacking interactions, the dinuclear complex molecules are assembled into layers, between which the hydrogen bonded H₂O molecules are located. The Cu atoms in 2 are octahedrally coordinated by two N atoms of one bpy ligand and four O atoms of two H₂O molecules and two sulfato groups with the sulfato O atoms at the trans positions and are bridged by sulfato groups into ¹[Cu(bpy)(H₂O)₂(SO₄)_2/2] chains. Through the interchain π—π stacking interactions and interchain C—H···O hydrogen bonds, the resulting chains are assembled into bi—chains, which are further interlinked into layers by O—H···O hydrogen bonds between adjacent bichains.     

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.     

Synthese,Kristallstruktur und thermischer Abbau von Mg(H2O)6[B12H12] · 6 H2O

Synthesis, Crystal Structure, and Thermal Decomposition of Mg(H₂O)₆[B₁₂H₁₂] · 6 H₂O By reaction of an aqueous solution of the free acid (H₃O)₂[B₁₂H₁₂] with MgCO₃ and subsequent isothermic evaporation of the resulting solution to dryness, colourless, bead‐shaped single crystals of the dodecahydrate of magnesium dodecahydro closo‐dodecaborate Mg(H₂O)₆[B₁₂H₁₂] · 6 H₂O (cubic, F4₁32; a = 1643.21(9) pm, Z = 8) emerge. The crystal structure is best described as a NaTl‐type arrangement in which the centers of gravity of the quasi‐icosahedral [B₁₂H₁₂]^2— anions (d(B—B) = 178—180 pm, d(B—H) = 109 pm) occupy the positions of Tl^— while the Mg²⁺ cations occupy the Na⁺ positions. A direct coordinative influence of the [B₁₂H₁₂]^2— units at the Mg²⁺ cations is however not noticeable. The latter are octahedrally coordinated by six water molecules forming isolated hexaaqua complex cations [Mg(H₂O)₆]²⁺ (d(Mg—O) = 206 pm, 6×). In addition, six “zeolitic” water molecules are located in the crystal structure for the formation of a strong O—H^δ+···^δ—O‐hydrogen bridge‐bonding system. The evidence of weak B—H^δ—···^δ+H—O‐hydrogen bonds between water molecules and anionic [B₁₂H₁₂]^2— clusters is also considered. Investigations on the dodecahydrate Mg[B₁₂H₁₂] · 12 H₂O (≡ Mg(H₂O)₆[B₁₂H₁₂] · 6 H₂O) by DTA/TG measurements showed that its dehydration takes place in two steps within a temperature range of 71 and 76 °C as well as at 202 °C, respectively. Thermal treatment eventually leads to the anhydrous magnesium dodecahydro closo‐dodecaborate Mg[B₁₂H₁₂].     

[Gd(C10H9N2O4)(C10H8N2O4)(H2O)3]2·phen·4H2O的晶体结构和生物活性

在水乙醇混合溶剂中，首次得到了2-羰基丙酸水杨酰腙、1，10-菲啰啉与硝酸钆形成的配合物[Gd(C₁₀H₉N₂O₄)(C₁₀H₈N₂O₄)(H₂O)₃]₂·phen·4H₂O，并测试了其单晶结构。该配合物属三斜晶系，空间群为P-1。每个配合物分子中有两个九配位的钆的结构单元，每个钆离子与两个三齿配体2-羰基丙酸水杨酰腙（分别以负一价和负二价形式）和三个水分子配位。每个钆单元在空间呈扭曲的单帽四方反棱柱。同时还有一个游离的1，10-菲啰啉存在于晶格中，通过氢键与配位水作用。生物活性试验表明该配合物对三种病原菌有一定的抑菌活性。     

A Novel Mixed‐Ligand Manganese(II) Complex Containing a V‐shape Water Trimer: Synthesis,Structure and Magnetic Properties of {[Mn(azpy)2(dca)(H2O)2](ClO4)(azpy)(H2O)2}n

A novel mixed‐ligand complex {[Mn(azpy)₂(dca)(H₂O)₂](ClO₄)(azpy)(H₂O)₂}_n ( 1 ) has been synthesized and characterized by single crystal X‐ray analysis, elemental analysis, IR spectroscopy and variable temperature magnetic measurement. The 4,4′‐azopyridine and dicyanamide ligands are abbreviated as azpy and dca, respectively. The crystal structure of 1 revealed that the 1D covalent bonding chains constructed by μ_1,5‐dca bridging the Mn^II ions are linked together via O–H···N and O–H···O hydrogen bonds and π‐π stacking interactions into a 3D supramolecular structure. V‐shape (bent) water trimers were also found in the structure. The water clusters play an important role in the formation of the 3D supramolecular structure. The determination of the variable temperature magnetic susceptibilities (2–300 K) shows the existence of a very weak antiferromagnetic interaction with a J value of ?0.16 cm^?1.     

Structure and Magnetic Properties of a Novel Two‐Dimensional Complex from 1, 3, 5‐Benzenetricarboxylate and Neodymium(III) — {[Nd(1, 3, 5‐benzenetricarboxylate)(H2O)4] · H2O}n

A unique neodymium(III) complex, {[Nd(BTC)(H₂O)₄] · H₂O}_n (BTC = 1, 3, 5‐benzenetricarboxylate), was obtained from the reaction between Nd(ClO₄)₃ · xH₂O and Na₃BTC. Coordination bonds, hydrogen bonds, and π‐π stacking form a supramolecular structure with a novel, two‐dimensional framework. The temperature‐dependent magnetic susceptibilities were analyzed by the Curie‐Weiss law; the following values were found C = 1.32, θ = —18.3 K, respectively.     

A Novel 3D Framework Coordination Polymer based on Succinato bridged Helical Chains Connected by 4, 4' ‐ Bipyridine: [Cu(bpy)(H2O)2(C4H4O4)]?2H2O

Blue needle—shaped crystals of [Cu(bpy)(H₂O)₂(C₄H₄O₄)]· 2H₂O were obtained by slow evaporation of a methanolic aqueous solution containing a fresh Cu(C₄H₄O₄)· 2H₂O precipitate, 4, 4′—bipyridine, and ammonia. Within the complex, the six—coordinated Cu atoms are linked by bis—monodentate gauche succinate anions into chains propagating helically around the [001] axis. The chains are interconnected by 4, 4′—bipyridine ligands into a 3D framework with the crystal H₂O molecules located in the channels along the [100], [010] and [110] directions. The Cu²⁺ ions are in distorted octahedral coordination of two nitrogen and four oxygen atoms (equatorial bonds: Cu—N 1.986(5), 2.015(5)Å; Cu—O 1.950(6), 1.954(6)Å; axial bonds Cu—O: 2.524(9), 2.539(8)Å). Furthermore, the thermal and magnetic behavior of the compound will be discussed. Crystal data: hexagonal, P6₁ (no. 169), a = 11.066(2)Å, c = 24.965(5)Å, V = 2647.5(8)ų, Z = 6, R = 0.0528 and wR₂ = 0.1103 for 1426 observed reflections (F_o² > 2σ(F_o²)) out of 2170 unique reflections.     

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.     

Koordinationspolymere 1, 2‐Dithiooxalato‐ und 1, 2‐Dithioquadratato‐Komplexe. Synthese und Strukturen von [BaCr2(bipy)2(1, 2‐dtox)4(H2O)2], [Ni(cyclam)(1, 2‐dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2‐dtsq)2(H2O)2]·2H2O und [H3O][H5O2][Cu(cyclam)]3[Cu2(1, 2‐dtsq)3]2

Coordination Polymeric 1, 2‐Dithiooxalato and 1, 2‐Dithiosquarato Complexes. Syntheses and Structures of [BaCr₂(bipy)₂(1, 2‐dtox)₄(H₂O)₂], [Ni(cyclam)(1, 2‐dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2‐dtsq)₂(H₂O)₂]·2H2₂, and [H₃O][H₅O₂][Cu(cyclam)]₃[Cu₂(1, 2‐dtsq)₃]₂ 1, 2‐Dithioxalate and 1, 2‐dithiosquarate ions have a pair of soft and hard donor centers and thus are suited for the formation of coordination polymeric complexes containing soft and hard metal ions. The structures of four compounds with building blocks containing these ligands are reported: In [BaCr₂(bipy)₂(1, 2‐dtox)₄(H₂O)₂] Barium ions and pairs of Cr(bipy)(1, 2‐dtox)₂ complexes form linear chains by the bisbidentate coordination of the dithiooxalate ligands towards Ba²⁺ and Cr³⁺. In [Ni(cyclam)(1, 2‐dtsq)]·2DMF short NÖH···O hydrogen bonds link the NiS₂N₄‐octahedra with C_2v‐symmetry to an infinite chain. In [Ni(cyclam)Mn(1, 2‐dtsq)₂(H₂O)₂]·2H₂O the 1, 2‐dithiosquarato ligand shows a rare example of S‐coordination towards manganese(II). The sulfur atoms of cis‐MnO₂S₄‐polyedra are weakly coordinated towards the axial sites of square‐planar NiN₄‐centers, thus forming a zig‐zag‐chain of Mn···Ni···Mn···Ni polyhedra. [H₃O][H₅O₂][Cu (cyclam)]₃[Cu₂(1, 2‐dtsq)₃]₂ contains square planar [Cu^II(cyclam)]²⁺ ions and dinuclear [Cu^I₂(1, 2‐dtsq)₃]^4— ions. Here each copper atom is trigonally planar coordinated by S‐donor atoms of the ligands. The Cu…Cu distance is 2.861(4)Å.     

[Yb(H2O)8][Cd3Cl9(H2O)]·6H2O

The title compound, namely octa­aqua­ytterbium(III) aqua­nona­chloro­tricadmate(II) hexa­hydrate, [Yb(H₂O)₈][Cd₃Cl₉(H₂O)]·6H₂O, was prepared by evaporation at 278 K from an aqueous solution of the ternary system YbCl₃–CdCl₂–H₂O and was characterized by elemental chemical analysis and by X‐ray powder and single‐crystal diffraction studies. The crystal structure can be viewed as being built from layers of double chains of CdCl₆ and CdCl₅(H₂O) octahedra separated by antiprismatic [Yb(H₂O)₈]³⁺ cations. The stabilization of the structure is ensured by O—H⋯O and O—H⋯Cl hydrogen bonds. A comparison with the structures of SrCd₂Cl₆·8H₂O and CeCd₄Cl₁₁·13H₂O is presented.     

Crystal structures of sodium magnesium selenate decahydrate,Na2Mg(SeO4)2·10H2O,a new selenate salt,and sodium magnesium selenate dihydrate,Na2Mg(SeO4)2·2H2O

Metal selenates crystallize in many instances in isomorphic structures of the corresponding sulfates. Sodium magnesium selenate decahydrate, Na₂Mg(SeO₄)₂·10H₂O, and sodium magnesium selenate dihydrate, Na₂Mg(SeO₄)₂·2H₂O, were synthesized by preparing solutions of Na₂SeO₄ and MgSeO₄·6H₂O with different molar ratios. The structures contain different Mg octahedra, i.e. [Mg(H₂O)₆] octahedra in the decahydrate and [MgO₄(H₂O)₂] octahedra in the dihydrate. The sodium polyhedra are also different, i.e. [NaO₂(H₂O)₄] in the decahydrate and [NaO₆(H₂O)] in the dihydrate. The selenate tetrahedra are connected with the chains of Na polyhedra in the two structures. O—H…O hydrogen bonding is observed in both structures between the coordinating water molecules and selenate O atoms.     

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.     

Nd2(SeO3)2(SeO4) · 2H2O – a Mixed‐Valence Compound containing Selenium in the Oxidation States +IV and +VI

Pale pink crystals of Nd₂(SeO₃)₂(SeO₄) · 2H₂O were synthesized under hydrothermal conditions from H₂SeO₃ and Nd₂O₃ at about 200 °C. X‐ray diffraction on powder and single‐crystals revealed that the compound crystallizes with the monoclinic space group C 2/c (a = 12.276(1) Å, b = 7.0783(5) Å, c = 13.329(1) Å, β = 104.276(7)°). The crystal structure of Nd₂(SeO₃)₂(SeO₄) · 2H₂O is an ordered variant of the corresponding erbium compound. Eight oxygen atoms coordinate the Nd^III atom in the shape of a bi‐capped trigonal prism. The oxygen atoms are part of pyramidal (Se^IVO₃)^2? groups, (Se^VIO₄)^2? tetrahedra and water molecules. The [NdO₈] polyhedra share edges to form chains oriented along [010]. The selenate ions link these chains into layers parallel to (001). The layers are interconnected by the selenite ions into a three‐dimensional framework. The dehydration of Nd₂(SeO₃)₂(SeO₄) · 2H₂O starts at 260 °C. The thermal decomposition into Nd₂SeO₅, SeO₂ and O₂ at 680 °C is followed by further loss of SeO₂ leaving cubic Nd₂O₃.     

Synthesis,Crystal Structure and Magnetic Properties of a 1‐D Polymer, [Cu(NITpPy)2(H2TCB)(H20)]·2H2O

A novel complex [Cu(NnpPy)₂(H_lTCB)(H₁O)]·2H₂O (NITpPy = 2‐(pyrid‐4′‐yl)‐4,4,5,5‐tetramethyl‐1, 3‐dioxoimidazoline; H₂TCB = 1, 5‐dicarboxybenzene carboxylic‐2, 4‐diacid) has been synthesized and characterized by X‐ray crystallography analysis. The crystal structure consists of infinite chains of Cu‐(NITpPy)₂(H₂O) units linked by H₂TCB ligands. The complex crystallizes in triclinic system with space group PI. Crystal data: a = 1.0594(2) nm, b = 1.3830(3) nm, c = 1.5551(3) nm, a = 67.75(3)°, β = 89.83(3)°, γ = 70.54(3)°. The variable magnetic susceptibility studies lead to magnetic coupling constant values of J₁= ?11.18 cm‐¹ (Cu—Rad) and J₂ = ?4.06 cm^?1 (Cu—Cu).     

A novel amido–pyrophosphate MnII chelate complex with the synthetic ligand O{P(O)[NHC(CH3)3]2}2 (L): [Mn(L)2{OC(H)N(CH3)2}2]Cl2·2H2O

The title complex, trans‐bis(dimethylformamide‐κO)bis{N,N′‐N′′,N′′′‐tetra‐tert‐butyl[oxybis(phosphonic diamide‐κO)]}manganese(II) dichloride dihydrate, [Mn(C₁₆H₄₀N₄O₃P₂)₂(C₃H₇NO)₂]Cl₂·2H₂O, is the first example of a bis‐chelate amido–pyrophosphate (pyrophosphoramide) complex containing an O[P(O)(NH)₂]₂ fragment. Its asymmetric unit contains half of the complex dication, one chloride anion and one water molecule. The Mn^II atom, located on an inversion centre, is octahedrally coordinated, with a slight elongation towards the monodentate dimethylformamide ligand. Structural features of the title complex, such as the P=O bond lengths and the planarity of the chelate ring, are compared with those of previously reported complexes with six‐membered chelates involving the fragments C(O)NHP(O), (X)NP(O) [X = C(O), C(S), S(O)₂ and P(O)] and O[P(O)(N)₂]₂. This analysis shows that the six‐membered chelate rings are less puckered in pyrophosphoramide complexes containing a P(O)OP(O) skeleton, such as the title compound. The extended structure of the title complex involves a linear aggregate mediated by N—H...O and N—H...Cl hydrogen bonds, in which the chloride anion is an acceptor in two additional O—H...Cl hydrogen bonds.     

Selten‐Erd‐Metall‐Koordinationspolymere: Synthesen und Kristallstrukturen von drei neuen Glutaraten, [Pr2(Glu)3(H2O)4] · 10,5H2O, [Pr(Glu)(H2O)2]Cl und [Er(Glu)(GluH)(H2O)2]

Rare‐Earth‐Metal Coordination Polymers: Syntheses and Crystal Structures of Three New Glutarates, [Pr₂(Glu)₃(H₂O)₄] · 10.5H₂O, [Pr(Glu)(H₂O)₂]Cl, and [Er(Glu)(GluH)(H₂O)₂] The new rare‐earth dicarboxylates [Pr₂(Glu)₃(H₂O)₄] · 10.5H₂O ( 1 ), [Pr(Glu)(H₂O)₂]Cl ( 2 ) and [Er(Glu)(GluH)(H₂O)₂] ( 3 ) were obtained from the reactions of glutaric acid with PrCl₃·6H₂O and Er(OH)₃, respectively. The crystal structures were determined by single‐crystal X‐ray diffraction. [Pr₂(Glu)₃(H₂O)₄] · 10,5H₂O crystallizes in the orthorhombic space group Pnma (no. 62) with a = 871.7(4), b = 3105.0(9), c = 1308.3(9) pm and Z = 4. The crystals of [Pr(Glu)(H₂O)₂]Cl are monoclinic (I2/a; no. 15) with a = 786.2(1), b = 1527.6(2) c = 801.2(1) pm, β = 99.78(1)° and Z = 4. [Er(Glu)(GluH)(H₂O)₂] crystallizes in the monoclinic space group P2₁/a (no. 14) with lattice parameters of a = 882.4(1), b = 1375.3(2), c = 1267.4(2) pm, β = 107.13(1)° and Z = 4. The rare‐earth cations have the coordination numbers 10 ( 1 ), 8 + 1 ( 2 ) and 9 ( 3 ). The individual polyhedra are connected to chains and further to sheets in 1 and 2 and to double chains in 3 . Only in the water‐rich compound 1 there are channels that contain crystal water molecules. It, therefore, has a considerably lower density than 2 and 3 .     

Orientational disorder of [Mg(H2O)6] octa­hedra in the novel magnesium selenite hydrate Mg(SeO3)·7.5H2O

The crystal structure of magnesium selenite 7.5‐hydrate, Mg(SeO₃)·7.5H₂O (space group P6₃/mmc), is characterized by two crystallographically distinct [Mg(H₂O)₆]²⁺ octa­hedra, one of which is disordered over two different orientations. The selenite groups and water mol­ecules (with partially disordered H atoms) bridge the octa­hedra via hydrogen bonds. All the atoms are located on special positions, except for one water mol­ecule.     

Synthesis,Crystal Structure,and Magnetic Properties of {[Cu(phen)]2(C4H2O4)2} · 4.5H2O with C4H4O4 = Maleic Acid

Reaction of CuCl₂ · 2H₂O, phenanthroline, maleic acid and NaOH in CH₃OH/H₂O (1:1 v/v) at pH = 7.0 yielded blue {[Cu(phen)]₂(C₄H₂O₄)₂} · 4.5H₂O, which crystallizes in the monoclinic space group C2/c (no. 15) with cell dimensions: a = 18.127(2)Å, b = 12.482(2)Å, c = 14.602(2)Å, β = 103.43(1)°, U = 3213.5(8)ų, Z = 4. The crystal structure consists of the centrosymmetric dinuclear {[Cu(phen)]₂(C₄H₂O₄)₂} complex molecules and hydrogen bonded H₂O molecules. The Cu atoms are each square‐pyramidally coordinated by two N atoms of one phen ligand and three carboxyl O atoms of two maleato ligands with one carboxyl O atom at the apical position (d(Cu‐N) = 2.008, 2.012Å, equatorial d(Cu‐O) = 1.933, 1.969Å, axial d(Cu‐O) = 2.306Å). Two square‐pyramids are condensed via two apical carboxyl O atoms with a relatively larger Cu···Cu separation of 3.346(1)Å. The dinuclear complex molecules are assembled via the intermolecular π—π stacking interactions into 1D ribbons. Crossover of the resulting ribbons via interribbon π—π stacking interactions forms a 3D network with the tunnels occupied by H₂O molecules. The title complex behaves paramagnetically between 5—300 K, following the Curie‐Weiss law _χm(T—θ) = 0.435 cm³ · mol^—1 · K with θ = 1.59 K.