Structure and thermal behavior of the layered zincophosphate [NH3-CH2-CH(NH3)-CH3](ZnPO4)2

A zinc phosphate with the composition [NH₃-CH₂-CH(NH₃)-CH₃](ZnPO₄)₂, containing the doubly protonated 1,2-diaminopropane (abbr. HDAP), was synthesized by hydrothermal crystallization of zinc nitrate, phosphoric acid, 1,2-diaminopropane and trimethylenedipiperidine. The single crystal analysis shows a layered inorganic-organic structure built up of a sandwich-like motif of alternating inorganic layers and HDAP cations (trimethylenedipiperidine not being a constituent of the structure). The HDAP species are found to be disordered and serve as bridges between two adjacent inorganic layers which are separated by 3.95 Å. The bridging interaction occurs via a hydrogen-bonding network. The inorganic layer features a pattern of four-membered rings involving two ZnO₄ and two PO₄ tetrahedra connected by sharing O atoms. Thermal analysis shows that the compound is stable up to 370 °C and that the thermal decomposition of HDAP occurs in two steps between 370 and 460 °C, causing the collapse of the structure. The first decomposition step corresponds to ammonia removal which proceeds with a high activation energy (E_a = 282 kJ mol⁻¹). The high E_a value is mainly attributed to strong electrostatic interactions between organic cations and anionic inorganic layers, the disruption of the interactions being the main reason for structural collapse after the HDAP removal.     

Hydrothermal synthesis and crystal structure of one-dimensional organic/inorganic hybrid material: [Mo4O12(2,2′-bpy)3]n

A new polyoxomolybdenum compound [Mo₄O₁₂(2,2′-bpy)₃]_n (1) (2,2′-bpy = 2,2′-bipyridine) has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis, and single crystal X-ray diffraction. The solid state structure is a 1D chain with a repeat unit of three corner-sharing {MoO₄N₂} octahedra and one {MoO₄} tetrahedron.     

Cyano-bridged cluster-metal coordination compound: synthesis and crystal structure of [Cu(NH3)3][Cu(NH3)4][Cu(NH3)5][W4Te4(CN)12]·5H2O

Dark-brown single crystals of the title compound 1 were obtained in high yield by layering a CuCl₂ solution in 25% aqueous ammonia on a glycerol solution of K₆[W₄Te₄(CN)₁₂]·5H₂O. The complex 1 was characterized by single crystal X-ray diffraction analysis and IR spectroscopy. The X-ray structure of 1 reveals a polymeric chain cyano-bridged cluster-metal coordination compound. The [W₄Te₄(CN)₁₂]⁶⁻ cluster anions are linked one to another by Cu²⁺ cations through coordination by nitrogen atoms of the CN groups.     

Solution-mediated syntheses and characterizations of two new zincophosphites [C6H14N2]0.5[Zn(H2PO3)2] and [C4H12N2]0.5[(CH3)2NH2][Zn2(HPO3)3]

Two new zincophosphites [C₆H₁₄N₂]_0.5[Zn(H₂PO₃)₂] 1 and [C₄H₁₂N₂]_0.5[(CH₃)₂NH₂][Zn₂(HPO₃)₃] 2 have been solvothermally synthesized in mixed solvents of N,N-dimethylformamide (DMF) and 1,4-dioxane (DOA), respectively. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a neutral inorganic chain formed by ZnO₄ and HPO₂(OH) units. Interestingly, the left- and right-handed hydrogen-bonded helical chains are alternately formed via the hydrogen-bonds between two adjacent chains. Compound 2 exhibits a layer structure with 4- and 12-MRs formed by ZnO₄ and HPO₃ units, in which two kinds of organic amine molecules both act as countercations to compensate the overall negative electrostatic charge of the anionic network.     

Rb2[B12(OH)12]·2H2O and Rb2[B12(OH)12]·2H2O2: Hydrate and perhydrolate of rubidium dodecahydroxo-closo-dodecaborate

The orthorhombically crystallizing salts Rb₂[B₁₂(OH)₁₂]·2H₂O (a = 1576.81(9), b = 813.08(5), c = 1245.32(7) pm) and Rb₂[B₁₂(OH)₁₂]·2H₂O₂ (a = 1616.54(9), b = 814.29(5), c = 1260.12(7) pm) could be prepared from Rb₂[B₁₂H₁₂] and hydrogen peroxide. Both crystal structures were determined by X-ray single crystal diffraction and refined in the space group Cmce. They are not isostructural to the other compounds containing icosahedral dodecahydroxo-closo-dodecaborate dianions [B₁₂(OH)₁₂]²⁻ and potassium, rubidium or cesium cations already known to literature, but both title compounds crystallize quasi-isotypically exhibiting Rb⁺ cations in 10-fold oxygen coordination. The hydrogen peroxide adduct (Rb₂[B₁₂(OH)₁₂]·2H₂O₂) is explosive on shock and heat, while the hydrate (Rb₂[B₁₂(OH)₁₂]·2H₂O) is not.     

Ln2(O2CCH2PO3)2(H2O)3 · H2O (Ln = La, Pr, Nd, Sm): Layered lanthanide phosphonoacetates containing two-dimensional -Ln-O- linkages

Four novel isostructural lanthanide phosphonate compounds with formula Ln₂(O₂CCH₂PO₃)₂(H₂O)₃ · H₂O [Ln = La (1), Pr (2), Nd (3), Sm (4)] have been prepared through hydrothermal reactions of phosphonoacetate acid and lanthanide nitrates. All show layered structures made up of {LnO₉} polyhedra and {CPO₃} tetrahedra with the lattice water molecules locating between the layers. Within the layer, chains of edge-sharing {LnO₉} polyhedra are connected via corner-sharing by phosphonate oxygens forming a two-dimensional -Ln-O- linkage. Thermal analyses and XRD measurements reveal that the framework structures can be maintained up to 400 °C.     

The crystal and molecular structure of [Co(NH3)5PO4]·3H2O,a Na+-K+ ATPase probe

The title compound, Co(NH₃)₅PO₄, prepared by a modified literature procedure, was used to study the inhibition of Na⁺-K⁺ ATPase and to serve as a structural model for ML₄(nucleotide) complexes. The structure was determined by single crystal X-ray diffraction techniques. The crystals are monoclinic, space group P2₁/n, a = 8.638(3), b = 14.517(2), c = 9.145(2) Å, and β = 112.71(2)°. The structure, solved by the heavy atom method to an R value of 3.3% for 1924 reflections, consists of a slightly distorted octahedron with the cobalt bound to the five amines and a monodentate phosphate. Solution structural data is taken from ³¹P NMR measurements. From comparison with other metal phosphate complexes it is concluded that multiple monodentate coordination of a di- or triphosphate closely resembles the coordination of a monophosphate This is based on the similarity of the MO bond angle which is 129.6° in the present example.     

Hydrothermal synthesis and characterization of a novel 3D open framework structure of mixed valence ethylenediamine-vanadium phosphate: [C2H10N2][(HVO3)(HVO2) (PO4)]

A new three-dimensional open framework structure of mixed valence ethylenediamine-vanadium phosphate [C₂H₁₀N₂][(HV^IVO₃)(HV^VO₂)(PO₄)] (1), has been synthesized under mild hydrothermal conditions and characterized by elemental analyses, IR, fluorescent spectrum, TG-DTA and single crystal X-ray diffraction. Compound 1 exhibits a novel three-dimensional (3D) vanadium phosphate anion framework composed of vanadium, phosphate, and oxygen atoms through covalent bonds, with the diprotonated ethylenediamine [NH₃CH₂CH₂NH₃]²⁺ cations residing in the channels along c-axis. The organic diprotonated ethylenediamine cations interact with the O atoms in the inorganic network through hydrogen bonds. The electrochemical behavior of 1 has also been studied in detail by cyclic voltammograms, which is very important for practical applications in electrode modification. Furthermore, the strong photoluminescence property of compound 1 is also measured at room temperature.     

Hydrothermal synthesis and structure of [Ni(tpyrpyz)2]2[Mo4O12F2][Mo6O19] · 2H2O, a material exhibiting an unusual tetranuclear polyoxofluoromolybdate cluster [Mo4O12F2]

The hydrothermal reaction of a solution of Ni(CH₃CO₂)₂ · 4H₂O, MoO₃, tetra-4-pyridylpyrazine, H₂O₃PCH₃, and HF at 200 °C for 96 h yields orange crystals of [Ni(tpyrpyz)₂]₂[Mo₄O₁₂F₂][Mo₆O₁₇] · 2H₂O (1 · 2H₂O). The structure consists of discrete {Ni(tpyrpyz)₂}²⁺ cations and {Mo₆O₁₉}²⁻ and {Mo₄O₁₂F₂}²⁻ anionic clusters. The hexamolybdate is the well-documented octahedron of octahedra, that is, six {MoO₆} octahedra in a compact edge-sharing arrangement. The novel oxyfluoride cluster {Mo₄O₁₂F₂}²⁻ features two {MoO₄F₂} octahedra, sharing the edge defined by the fluoride ligands; the octahedral Mo sites corner-share to two {MoO₄} tetrahedra in the μ₂-O, O^′ bridging mode.     

Hydrothermal synthesis and structure of an open framework Co0.7Zn1.3(PO4)2(NH3-CH2CH2NH3) and Co6.2(OH)4(PO4)4Zn1.80, a new adamite type phase

The hydrothermal reaction of cobalt(II)oxalate di-hydrate, zinc oxide, and triethyl-orthophosphate, using 1,2-diaminoethane as structure directing template in water, produced two major crystal phases in almost equal amount: the purple crystals of [NH₃-CH₂CH₂NH₃][Co_0.7Zn_1.3(PO₄)₂] (1) and the red burgundy crystals of Co_6.2(OH)₄(PO₄)₄Zn_1.80 (2), a new adamite type phase. The structure of [NH₃-CH₂CH₂NH₃] [Co_0.7Zn_1.3(PO₄)₂] (1) exhibits a 3D open framework built from PO₄ and (Co/Zn)O₄ tetrahedra, and (Co/Zn)O₅ trigonal bipyramids, forming two major channels, an 8-membered ring channel and a 16-membered ring channel, that host the ethanediammonium ions. The Co_6.2(OH)₄(PO₄)₄Zn_1.80 (2) is isomorphous with adamite-type M₂(OH)XO₄ structure, with a condensed vertex and edge sharing network of (Co/Zn)O₅, and distorted CoO₆, and PO₄ subunits. The cobalt preference for higher coordination numbers is displayed in this structure, where the octahedral sites are wholly occupied by cobalt. Thermal analysis confirmed that these compounds display high thermal stability.     

Spectroscopic and magnetic properties of diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe) ligand with perchlorate transition metal salts. Crystal structure of [Cu(4-pmOpe)2(ClO4)2]

The perchlorate M(II) (M = Cu, Ni, Co) complexes with the diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe) ligand of the composition [M(4-pmOpe)₂ (H₂O)₂](ClO₄)₂ (M = Ni, Co) and [Cu(4-pmOpe)₂(ClO₄)₂] were prepared and studied. The ligand contains two donor atoms, i.e. pyridine nitrogen and phosphoryl oxygen atoms. In particular, the crystal structure of [Cu(4-pmOpe)₂(ClO₄)₂] was determined by the X-ray method. Its structure consists of a one-dimensional polymeric chain in which copper(II) ions are N,O-bridged by two 4-pmOpe organic ligands in a trans arrangement. Two perchlorate ions occupy the fifth and the sixth coordination sites. The Cu?Cu distance is 9.180 Å. The crystal packing is determined by the weak intermolecular C-H?O hydrogen contacts. The coordination compounds were identified and characterized by elemental analysis, spectroscopic and magnetic studies. Spectroscopic and magnetic results of the copper(II) compound are presented in the light of the crystal structure. The magnetic data indicate very weak intra- and interchain magnetic exchange interactions (J^’ = −0.43 and zJ^’ = 0.29 cm⁻¹, respectively). The spectroscopic and magnetic properties of the Co(II) and Ni(II) complexes indicate octahedral and polymeric structure of both compounds in which 4-pmOpe ligand also acts as N,O-bridge between metal ions.     

Syntheses, characterizations and crystal structures of two lead(II) diphosphonates: Pb2[NH(CH2PO3)2] · 2H2O and Pb3[HO2C(CH2)3NH(CH2PO3)2]2 · 2H2O

Hydrothermal reactions of lead(II) acetate and HO₂C(CH₂)₃N(CH₂PO₃H₂)₂ at 170 and 140 °C, respectively, resulted in two different lead diphosphonates, namely, Pb₂[NH(CH₂PO₃)₂] · 2H₂O (1), in which the butyric acid moiety of the HO₂C(CH₂)₃N(CH₂PO₃H₂)₂ has been cleaved and a novel layered compound, Pb₃[HO₂C(CH₂)₃NH(CH₂PO₃)₂]₂ · 2H₂O (2). Their crystal structures have been determined by single crystal X-ray diffraction. In compound 1, the interconnection of the lead(II) ions by bridging amino-diphosphonate ligands leads to the formation of a 3D network. Compound 2 features an unusual triple-layer structure with the non-coordinated butyric acid moieties as pendant groups between the layers.     

Synthesis and characterization of complexes of the type [Pt(amine)4]I2 and trans-[Pt(CH3NH2)2(H3CNC(CH3)2)2]I2 by crystallography and multinuclear magnetic resonance spectroscopy

Complexes of the type [Pt(amine)₄]I₂ were synthesized and characterized mainly by multinuclear (¹⁹⁵Pt, ¹H and ¹³C) magnetic resonance spectroscopy. The compounds were prepared with different primary amines, but not with bulky amines, due to steric hindrance. In ¹⁹⁵Pt NMR, the signals were observed between −2715 and −2769 ppm in D₂O. The coupling constant ³J(¹⁹⁵Pt-¹H) for the MeNH₂ complex is 42 Hz. In ¹³C NMR, the average values of the coupling constants ²J(¹⁹⁵Pt-¹³C) and ³J(¹⁹⁵Pt-¹³C) are 18 and 30 Hz, respectively. The crystal structure of [Pt(EtNH₂)₄]I₂ was determined by X-ray diffraction methods. The Pt atom is located on an inversion center. The structure is stabilized by H-bonding between the amines and the iodide ions. The compound with n-BuNH₂ was found by crystallographic methods to be [Pt(n-BuNH₂)₄]₂I₃(n-BuNHCOO). The crystal contains two independent [Pt(CH₃NH₂)₄]²⁺ cations, three iodide ions and a carbamate ion formed from the reaction of butylamine with CO₂ from the air. When the compound [Pt(CH₃NH₂)₄]I₂ was dissolved in acetone, crystals identified as trans-[Pt(CH₃NH₂)₂(H₃CNC(CH₃)₂)₂]I₂ were isolated and characterized by crystallographic methods. Two trans bonded MeNH₂ ligands had reacted with acetone to produce the two N-bonded Schiff base Pt(II) compound.     

X-ray crystal Structure of [1,2-bis(diphenylphosphino)ethane]bis(3,5-dimethylpyrazole-N)platinum(II) tetrafluoroborate dichloromethane solvate, [(Ph2PCH2CH2PPh2)Pt(3,4-Me2pzH)2][BF4]2·CH2Cl2

The crystal structure of the compound [(Ph₂PCH₂CH₂PPh₂)Pt(3,5-Me₂pzH)₂][BF₄]₂·CH₂Cl₂ has shown that the ligands around the Pt atom are approximately in a square planar coordination, whereas the pyrazole rings point roughly in the same direction, away from the coordination plane. This unusual conformation is probably due to the hydrogen bonds with fluorine atoms of the BF₄^? anion. Bond distances and angles are compared with those in other pyrazole complexes.     

A new arylimido derivative of polyoxometalate (Bu4N)2[Mo6O17(NAr)2] [Ar = 2,6-(CH3)2C6H3]: Synthesis, structure and physicochemical properties

A novel bifunctionalized arylimido derivative of hexamolybdate, (Bu₄N)₂[Mo₆O₁₇(NAr)₂] [Ar = 2,6-(CH₃)₂C₆H₃] (1), in which the two 2,6-dimethylaniline groups are bounded to hexamolybdate at the cis positions, was synthesized by a facile reaction of α-octamolybdate with 2,6-dimethylaniline using DCC as a dehydration agent. The existence of strong non-typical C-H?O hydrogen bonds plays an important role in crystal structure stabilization of compound 1. The results of fluorescence spectra show that the formation of a covalent bond between 2,6-dimethylaniline molecule and hexamolybdate could efficiently quench the fluorescence intensity of 2,6-dimethylaniline molecule, with a fluorescence quencher efficiency of 87.7%. Thermal analysis results indicate that two substituted 2,6-(CH₃)₂C₆H₃ molecules bonding to the same cluster dissociated at different temperature, in well agreement with the different MoN bond length in compound 1. The electrochemical behavior of modified 1-CPE has been studied in detail. Compared with the conventional polyoxometalate (POM)-modified electrode, 1-CPE presents a merit of remarkable stability over 500 cycles due to the insolubility of the POM nanoparticles, which is especially important for practical applications.     

Crystal structures of MoCl2(O)(O2)(OPMePh2)2 and mixtures of MoCl2(O2)(OPPh3)2 and MoCl2(O)(O2)(OPPh3)2: allylic alcohol isomerization studies using MoCl2(O)(O2)(OPMePh2)2

Adding one equivalent of H₂O₂ to compounds of stoichiometry MoCl₂(O)₂(OPR₃)₂, OPR₃ = OPMePh₂ or OPPh₃, leads to the formation of oxo-peroxo compounds MoCl₂(O)(O₂)(OPR₃)₂. The compound MoCl₂(O)(O₂)(OPMePh₂)₂ crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl₂(O)(O₂)(OPPh₃)₂, was not isolated in pure form, co-crystallized with MoCl₂(O)₂(OPPh₃)₂ in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on ¹⁸O isotopic studies and involves exchange between the alcohol and metal bonded O atoms.     

Trinuclear Cu(pn)2Ag2(CN)4: preparation, crystal structure and properties (pn=1,2-diaminopropane)

The new compound Cu(pn)₂Ag₂(CN)₄ (CPAC; pn=1,2-diaminopropane) was isolated from a reaction mixture containing CuSO₄, pn and K[Ag(CN)₂] and was characterized by chemical analysis, IR and UV-VIS spectroscopy, and magnetic studies. The crystal structure of CPAC is built up of trinuclear NC-Ag-CN-Cu(pn)₂-NC-Ag-CN molecules which are linked by hydrogen bonds and argentophilic interactions (Ag?Ag=3.26141(16) Å). The Cu(II) atom is coordinated in the equatorial plane by two chelate bonded pn ligands (mean Cu-N is 2.010(1) Å, while the axial positions are occupied by linear cyanoargentate anions acting as terminal ligands (Cu-N is 2.570(2) Å (2x)). The magnetic properties are well described by the Curie law down to 2 K.     

Ternary rare-earth transition metal phosphides. I. Synthesis and crystal structure of Ho5Ni19P12

Single crystals of the new phosphide Ho₅Ni₁₉P₁₂ were obtained by reacting the elemental components at high temperature. The compound crystallizes in the hexagonal space-group P$\text{6}$2m with the cell constants: a = 12.288 (2), c = 3.762 (2) Å, Z = 1. The structure has been determined from X-ray data and refined to a final R value of 0.049 for 271 independent reflections. It is derivative of the Hf₂Co₄P₃- type structure. Holmium atoms are in a trigonal- prismatic phosphorus coordination while nickel atoms occupy three different phosphorus polyhedra: triangle, tetrahedra and ‘square-planar’ pyramids. The atomic arrangement of Ho₅Ni₁₉P₁₂ appears as a combination of those observed in Zr₂Fe₁₂P₇ and Zr₆Ni₂₀P₁₃-type structures.     

Polymorphism in intercluster salt system: two crystal structures of [Al13O4(OH)24(H2O)12][H2W12O40](OH) · nH2O

In this paper, we report the syntheses and crystal structures of two intercluster salt compounds, [Al₁₃O₄(OH)₂₄(H₂O)₁₂][H₂W₁₂O₄₀](OH) · 20H₂O (1) and [Al₁₃O₄(OH)₂₄(H₂O)₁₂][H₂W₁₂O₄₀](OH) · 24H₂O (2). The crystal structures of these compounds show that they are polymorphs to each other with different modes of packing of the and ions. The structures of 1 and 2 can be described as alternating arrangements of ionic clusters that optimize electrostatic interactions and hydrogen bonds between them. The structure of 1 is analogous to the PtS structure and that of 2 is similar to the β-BeO structure with the clusters forming tetrahedral or square planar coordination geometries to each other.     

Synthesis, crystal structure and properties of [Cu(H2O)6][Cu2(nta)2(pyz)]·4H2O: A channeled solid with three-dimensional hydrogen-bonding network

We report the synthesis and characterization of [Cu^II(H₂O)₆][Cu^II₂(nta)₂(pyz)]·4H₂O. It consists of two molecular entities, a cation and an anion, containing divalent copper. These entities are held together by an extensive network of hydrogen-bonding to form a framework with channels (along the a-axis) housing molecules of water. The latter can be reversibly removed by evacuation at room temperature to give another crystal phase. The compound undergoes a fast solid-state reaction with KBr. Magnetic susceptibility data fit well to the sum of those of a dimer with a singlet-triplet gap of 9.21(5) K and a monomer.