Solid Solution Formation between Vanadium(V) and ­Tungs­ten(V) Oxide Phosphate

The solid solutions (V_1–xW_x)OPO₄ with β‐VOPO₄ structure type (0.0 ≤ x ≤ 0.01) and α_II‐VOPO₄ structure type (0.04 ≤ x ≤ 0.26) were obtained from mixtures of V^VOPO₄ and W^VOPO₄ by conventional solid state reactions and by solution combustion synthesis. Single crystals of up to 3 mm edge length were obtained by chemical vapor transport (CVT) (800 → 700 °C, Cl₂ as a transporting agent). Single crystal structure refinements of crystals at x = 0.10 [a = 6.0503(2) Å, c = 4.3618(4) Å, R₁ = 0.021, wR₂ = 0.058, 21 parameters, 344 independent reflections] and x = 0.26 [a = 6.0979(2) Å, c = 4.2995(1) Å, R₁ = 0.030, wR₂ = 0.081, 21 parameters, 346 independent reflections] confirm the α_II‐VOPO₄ structure type (P4/n, Z = 2) with mixed occupancy V/W for the metal site. Due to the specific redox behavior of W⁵⁺ and V⁵⁺, solid solutions (V_1–xW_x)OPO₄ should be formulated as (V^IV_xV^V_1–2xW^VI_x)OPO₄. The valence states of vanadium and tungsten are confirmed by XPS measurements. V⁴⁺ with d¹ configuration was identified by EPR spectroscopy and magnetic measurements. Electronic spectra of the solid solutions show the IVCT(V⁴⁺ → V⁵⁺) and the LMCT(O^2– → V⁵⁺). (V_0.74W_0.26)OPO₄ powders exhibit semi‐conducting behavior (E_g = 0.7 eV).     

Synthesis,Crystal Structure and Properties of Li2Cu5(PO4)4

Li₂Cu^II₅(PO₄)₄ has been obtained by various reactions starting from copper or Cu₂O. Crystallization was achieved using I₂ as oxidant and mineralizer. The new orthophosphate crystallizes in space group P$\bar{1}$ , Z = 2, with a = 6.0502(3) Å, b = 9.2359(4) Å, c = 11.4317(5) Å, α = 75.584(2)°, β = 80.260(2)°, γ = 74.178(2)°, at 293 K. Its structure has been determined from X‐ray single‐crystal data and refined to R₁ = 0.022{wR₂ = 0.058 for 4633 unique reflections with F_o > 4σ (F_o)}. From magnetic measurements μ_eff = 1.51 μ_B/Cu and θ_P = –37.4 K have been determined. The Vis/NIR spectrum of aqua‐green Li₂Cu₅(PO₄)₄ shows a single broad band centered around $\bar{1}$ = 12000 cm^–1. Magnetic behavior and spectrum are discussed within the angular overlap model.     

Synthesis,Crystal Structure and Characterization of the Copper Iron Phosphate Cu8Fe2O5(PO4)4

The system CuO‐Fe₂O₃‐P₂O₅ has been investigated by means of the solid state reaction between CuO, Fe₂O₃ and (NH₄)₂HPO₄ in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, IR spectroscopy and TG/DTA. Single crystals of a new quaternary phase Cu₈Fe₂P₄O₂₁ were achieved by cooling from the melt of the compound in a sealed, evacuated quartz ampoule. Cu₈Fe₂O₅(PO₄)₄ crystallizes in the monoclinic space group C2/m (No 12) with a = 15.9733(8) Å, b = 5.9438(3) Å, c = 9.5530(5) Å, β = 113.76(1)°, Z = 2. The three‐dimensional framework consists of [FeO₆] octahedra, three different [CuO₅] polyhedra and [PO₄] tetrahedra. Cu₈Fe₂P₄O₂₁ exhibits an incongruently melting point at 945 °C.     

The Non‐Centrosymmetric Crystal Structure of Molybdenum(VI) Oxide Bromide MoO2Br2

Red, transparent single crystals of molybdenum(VI) dioxide dibromide MoO₂Br₂ emerged as by‐product after thermal analyses of reaction mixtures comprising REBr₃ (RE = La or Gd) and MoO₃. The structure of this highly water sensitive compound can be described in the non‐centrosymmetric monoclinic space group Cc with the lattice constants a = 1522.33(15) pm, b = 390.61(4) pm, c = 771.09(8) pm, β = 104.394(7)° and four formula units per unit cell. Crystallographically unique Mo⁶⁺ cations are surrounded by four oxide and twobromide anions in the shape of distorted octahedra withthe two Br^– ligands situated in trans position to each other. These octahedra are interconnected by the four O^2– anions via vertices to form {MoO Br } layers parallel to the bc plane, whereas the bromide anions remain terminal. These sheets are piled along [100] with the Br^– anions pointing towards the center of square voids of adjacent layers.     

Synthesis,Crystal Structure and Spectroscopic Characterisation of Mono‐ and Dinuclear 5,5‐Diethylbarbiturato Complexes of Chromium(0) and Rhenium(I)

Addition of 5,5‐diethylbarbituric acid (H₂debarb, 1 ) to [CpCr(NO)₂Cl], [Re(CO)₅Br] or [(PPh₃)Re(CO)₄Br] in the presence of triethylamine and AgO₃SCF₃ (= AgOTf) resulted in the mono‐barbiturato complexes [CpCr(NO)₂(Hdebarb)] ( 2 ), [PPh₃Re(CO)₄(Hdebarb)] ( 3 ) and [Re(CO)₅(Hdebarb)] ( 4 ), respectively. Bis‐barbiturato complex [{(CO)₅Re}₂(debarb)] ( 5 ) with a doubly deprotonated barbiturate dianion formed when a molar ratio of metal complex to ligand of 2:1 was used. In the case of the rhenium complexes, AgO₃SCF₃ must be used additionally to cleave off bromide. All of the complexes were fully characterised by means of IR, mass and ¹H, ¹³C and ³¹P NMR spectra and elemental analysis. In addition, their solid‐state structures were determined by single‐crystal X‐ray diffraction studies. The complexes exhibit distorted pseudo‐tetrahedral ( 2 ) or pseudo‐octahedral ( 3 – 5 ) configuration around the metal atom. In all complexes the ring system of the Hdebarb ligand is essentially planar.     

Synthesis,Characterization and Biological Evaluation of Two Silver(I) trans‐Cinnamate Complexes as Urease Inhibitors

Two new silver(I) trans‐cinnamates, namely [Ag(2‐cca)(H₂O)]₂ ( 1 ) and [Ag(4‐cca)]_n ( 2 ) (2‐ccaH = 2‐chlorocinnamic acid and 4‐ccaH = 4‐chlorocinnamic acid), were synthesized and structurally characterized. Single crystal X‐ray studies reveal that each silver(I) atom in 1 is two‐coordinate by a 2‐chlorocinnamate ligand and one water molecule to afford a discrete centrosymmetric dimer with the ligand‐unsupported Ag···Ag interactions (3.218(4) Å), while a pair of symmetry‐related silver(I) atoms in 2 are clamped by two μ₂‐η¹:η¹ 4‐chlorocinnamate ligands to yield a binuclear silver(I) moiety incorporating a ligand‐supported Ag···Ag interaction (2.819(5) Å). Both complexes 1 and 2 show potent urease inhibitory activities with the respective IC₅₀ values of 0.66 and 1.10 μM.     

Synthesis,Crystal Structure,Magnetic Property,and Electronic Structure of Ba2YbInSe5

A new barium ytterbium indium selenide, Ba₂YbInSe₅, was obtained by conventional high temperature solid state reaction. The compound crystallizes in the noncentrosymmetric space group Cmc2₁ of the orthorhombic system. The structure contains infinite one‐dimensional anionic chains ¹_∞[YbInSe₅]^4–, which are built from YbSe₆ octahedra and InSe₄ tetrahedra and separated by Ba²⁺ cation. The magnetic measurement indicates that the compound is paramagnetic. In addition, the calculated bandgap is 0.29 eV.     

Phase Equilibria in the System CuO‐NiO‐P4O10 and Synthesis,Crystal Structure,and Characterization of the New Copper Nickel Oxide Phosphate Cu3NiO(PO4)2

The system CuO‐NiO‐P₄O₁₀ was investigated using a solid state reaction between CuO, NiO, and (NH₄)₂HPO₄ in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, TG/DTA, electrochemical measurements, IR, and UV/Vis spectroscopy. Single crystals of a new quaternary phase Cu₃NiO(PO₄)₂ were achieved by cooling the melted compound in a sealed, evacuated quartz ampoule. Cu₃NiO(PO₄)₂ crystallizes in the monoclinic space group P2₁/n (no 14) with a = 8.2288(2) Å, b = 9.8773(2) Å, c = 8.2777(3) Å, β = 107.82(2)°, Z = 4. The three‐dimensional framework consists of distorted tetragonal pyramides [Cu1O₅], distorted planar squares [Cu2O₄], octahedra [Cu3O₆], and [NiO₆] and [PO₄] tetrahedra. The TG‐DTA of the new phase showed an incongruent melting at 1055 °C. The open circuit voltage of this material was measured to determine the electrochemical properties. The measurement revealed an initial capacity of 236 Ah · g^–1 and a voltage plateau at 2.05 V. Furthermore, it was possible to identify the phase equilibria and to obtain the phase diagram at 900 °C.     

Synthesis and Characterization of Di‐ and Tricarbonylhydridomanganese(I) Complexes

Hydrido complexes [MnH(CO)₃L^1–3] [L¹ = 1,2‐bis‐(diphenylphosphanoxy)‐ethane ( 1 ); L² = 1,2‐bis‐(diisopropylphosphanoxy)ethane ( 2 ); L³ = 1,3‐bis‐(diphenylphosphanoxy)‐propane ( 3 )] were prepared by treating [MnH(CO)₅] with the appropriate bidentate ligand by heating to reflux. Photoirradiation of a toluene solution of complexes 1 and 2 in the presence of PPh_n(OR)_3–n (n = 0, 1; R = Me, Et) leads to the replacement of a CO ligand by the corresponding monodentate phosphite or phosphonite ligand to give new hydrido compounds of formula [MnH(CO)₂(L^1–2)(L)] [L = P(OMe)₃ ( 1a – 2a ); P(OEt)₃ ( 1b – 2b ); PPh(OMe)₂ ( 1c – 2c ); PPh(OEt)₂ ( 1d – 2d )]. All complexes were characterized by IR, ¹H, ¹³C and ³¹P NMR spectroscopy. In case of compounds 2 and 3 , suitable crystals for X‐ray diffraction studies were isolated.     

Binuclear Iron(I) Complex Containing Bridging Phenanthrene‐4,5‐dithiolate Ligand: Preparation,Spectroscopy, Crystal Structure,and Electrochemistry

A diiron hexacarbonyl complex containing bridging phenanthrene‐4,5‐dithiolate ligand is prepared by oxidative addition of Phenanthro[4,5‐cde][1,2]dithiin to Fe₂(CO)₉. The complex is investigated as a model for the active site of the [Fe–Fe] hydrogenase enzyme. The compound, [(μ‐PNT)Fe₂(CO)₆]; (PNT = phenanthrene‐4,5‐dithiolate), was characterized by spectroscopic methods (IR, UV/Vis and NMR) and X‐ray crystallography. The IR and proton NMR spectra of [(μ‐PNT)Fe₂(CO)₆] ( 4 ) are in agreement with a PNT ligand attached to a Fe₂(CO)₆ core. The infrared spectrum of 4 recorded in dichloromethane contains three peaks at 2001, 2040, and 2075 cm^–1 corresponding to the stretching frequency of terminal metal carbonyls. X‐ray crystallographic study unequivocally confirms the structure of the complex having a butterfly shape with an Fe–Fe bond length of 2.5365 Å close to that of the enzyme (2.6 Å). Electrochemical properties of [(μ‐PNT)Fe₂(CO)₆] have been investigated by cyclic voltammetry. The cyclic voltammogram of [(μ‐PNT)Fe₂(CO)₆] recorded in acetonitrile contains one quasi‐irreversible reduction (E_1/2 = –0.84 V vs. Ag/AgCl, I_pc/I_pa = 0.6, ΔE_p = 131 V at 0.1 V · s^–1) and one irreversible oxidation (E_pa = 0.86 V vs. Ag/AgCl). The redox of [(μ‐PNT)Fe₂(CO)₆] at E_1/2 = –0.84 V can be assigned to the one‐electron transfer processes; [Fe^I–Fe^I] → [Fe^I–Fe⁰] and [Fe^I–Fe⁰] → [Fe^I–Fe^I].     

Synthesis,Characterization and Crystal Structure of 4‐Amino‐1,2,4‐Δ2‐triazoline‐5‐thione and its Silver(I) Complex

The reaction of 4‐amino‐1,2,4‐Δ²‐triazoline‐5‐thione (ATT, 1 ) with AgNO₃ in methanol led to the complex [Ag(ATT)₂]NO₃ ( 2 ). 2 was characterized by elemental analyses, ¹H NMR, IR, and Raman spectroscopy as well as single‐crystal X‐ray diffraction. The molecular structure of 1 was also determined by single crystal X‐ray analysis. Crystal data for 1 at ?80 C: space group C2/c with a = 2107.4(2), b = 1425.1(1), c = 688.4(1) pm, β = 104.55(1)°, Z = 16, R₁ = 0.0514, crystal data for 2 at ?80 °C: space group P2₁/c with a = 675.7(1), b = 1321.1(1), c = 1311.2(1) pm, β = 90.03(1)°, Z = 4, R₁ = 0.0437.     

Polysulfonylamine. CLVIII [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 9 [2] Erhöhung der Kristallsymmetrie durch Kokristallisation: Monoklines Na[(CH3SO2)2N]·H2O und tetragonales NaK[(CH3SO2)2N]2·2H2O

Polysulfonylamines. CLVIII. Crystal Structures of Metal Di(methanesulfonyl)amides. 9. Enhancing Crystal Symmetry by Co‐crystallization: Monoclinic Na[(CH₃SO₂)₂N]·H₂O and Tetragonal NaK[(CH₃SO₂)₂N]₂·2H₂O The three‐dimensional coordination polymers NaA·H₂O ( 1 ) and NaKA₂·2H₂O ( 2 ), derived from the strong NH acid (MeSO₂)₂NH = HA, have been characterized by single crystal X‐ray diffraction at —95 °C ( 1 : monoclinic, space group C2/c, Z′ = 2; 2 : tetragonal, P4₃2₁2, Z′ = 1). The results suggest that structures with Z′ > 1 are good candidates for co‐crystallization experiments. Both packings display layer substructures built up from the multidentately coordinating anions, the aquo ligands and two kinds of chemically and/or crystallographically distinct cations, whereas cations of a third type are intercalated between the layers. All anions have the extended standard conformation of this species; 1 contains two pseudo‐C₂ symmetric A^—, 2 one pseudo‐C₂ and two crystallographically C₂ symmetric A^—. Details for structure 1 : a) The layer‐forming Na(1) and Na(3) cations are distributed over three distinctly separated planes, Na(1) occupies general positions and has a non‐octahedral O₅N environment, Na(3) resides on inversion centres that generate an octahedral O₆ coordination; b) one independent A^— is oriented vertically, the other parallel to the layer plane; c) the intercalated Na(2) ions occupy twofold rotation axes within a single plane and possess a non‐octahedral O₆ environment. Details for structure 2 : a) The layer‐forming K(1) and K(2) cations occupy twofold rotation axes within a unique plane and have chemically identically O₆N₂ coordination polyhedra approximating to hexagonal bipyramids; b) all A^— are oriented vertically to the layer plane; c) the intercalated sodium ions reside on pseudo‐inversion centres, have an octahedral O₆ environment and are distributed over two closely adjacent planes. Owing to the enhanced packing efficiency of the bimetal complex, the vertical layer repeat‐distance is reduced from 1140 pm for 1 to 720 pm for 2 . Each structure exhibits an infinite cation‐water chain that propagates in the direction of the layer stacking and contains the three independent cations.     

High Pressure Synthesis and Characterization of New Members of the RuSr2(RE,Ce)2Cu2O10 Family (RE = Y,Dy)

New members of the RuSr₂(RE_2?x, Ce_x)Cu₂O₁₀ family of magnetically ordered phases have been synthesized under high pressure / high temperature conditions for RE = Y (x = 0.5, 0.7) and Dy (x = 0.5). All compounds show tetragonal symmetry with cell parameters a ≈ 3.82 Å and c ≈ 28.4 Å. Magnetic susceptibility vs temperature measurements show ferromagnetic behaviour of these compounds with T_M = 120–140 K, depending on Ce content. These compounds are semiconducting and tend to transform into insulator, by increasing Ce content, as observed by the temperature dependence of the resistance.     

Crystal Structure and Disorder Phenomena of the Adduct of Neutral C60 and the Ionic Gold Complex (Ptol3)2AuNO3

The adduct C₆₀·(Ptol₃)₂AuNO₃ has been crystallized from toluene solutions of C₆₀ and (Ptol₃)₂AuNO₃ as violet, trigonal plate‐shaped crystals. The compound was studied by single‐crystal x‐ray diffraction ( , a = 1278.17(3), c = 2282.92(6) pm). The gold complex is dissociated into [(Ptol₃)₂Au]⁺ cations, which encapsulate the neutral C₆₀ molecules, and nitrate anions. The intermolecular interactions between the fullerene molecules and the gold complex cations and the resulting disorder is investigated. The crystal structure of C₆₀·(Ptol₃)₂AuNO₃ is providing an instructive example, demonstrating that symmetry‐matching is not always sufficient for avoiding disorder.     

Lanthanum (Oxo)nitridosilicates: From Ordered to Disordered Crystal Structures

The homeotypic compounds La_16.32Ba_1.82Sr_7.86[Si₆₀N_92.32O_3.68]O₁₂ and La_13.68Sr_12.32[Si₆₀N₉₆]F_6.32O_5.68 were synthesized at high temperature (1600/1500 °C) in a radio‐frequency furnace. The crystal structures [I$\bar{4}$ m (no. 217), Z = 1, a = 13.3360(10)/13.3258(10) Å and V = 2371.8(5)/2366.4(5) ų] were solved and refined on basis of single‐crystal X‐ray diffraction data and were corroborated by lattice‐energy calculations (Madelung part of lattice energy, MAPLE) powder X‐ray diffraction data and FTIR spectroscopy. They consist of a three‐dimensional network of allside corner sharing SiN_4–xO_x tetrahedra. The framework is characterized by double dreier rings. La_16.32Ba_1.82Sr_7.86[Si₆₀N_92.32O_3.68]O₁₂ represents an oxonitridosilicate oxide and La_13.68Sr_12.32[Si₆₀N₉₆]F_6.32O_5.68 a nitridosilicate fluoride oxide, as the crystal structures contain non‐condensed (O^[0]/O,F^[0]) anions. The first compound is isotypic to Sr₃Ln₁₀Si₁₈Al₁₂O₁₈N₃₆ (Ln = Ce, Pr, Nd; Z = 2), whereas the latter describes a disordered model of the crystal structure, which is homeotypic to the mentioned SiAlONs.     

High‐Pressure Synthesis of Cd(NH3)2[B3O5(NH3)]2: Pioneering the Way to the Substance Class of Ammine Borates

To date, the access to the substance class of borates containing nitrogen, for example, nitridoborates, oxonitridoborates, or amine borates, was an extreme effort owing to the difficult starting materials and reaction conditions. Although a number of compounds containing boron and nitrogen are known, no adduct of ammonia to an inorganic borate has been observed so far. A new synthetic approach starting from the simple educts CdO, B₂O₃, and aqueous ammonia under conditions of 4.7 GPa and 800 °C led to the synthesis of Cd(NH₃)₂[B₃O₅(NH₃)]₂ as the first ammine borate. We thoroughly characterized this compound on the basis of low‐temperature single‐crystal and powder X‐ray diffraction data, IR and Raman spectroscopy, and by quantum theoretical calculations. This contribution shows that the adduct of NH₃ to the BO₃ group of a complex B–O network can be stabilized, opening up a fundamentally new synthetic route to nitrogen‐containing borates.     

Vanadyl phosphate dihydrate,a solid acid: the role of water in VOPO4·2H2O and its sodium derivatives Na x (VIV x VV 1−x O)PO4·(2−x)H2O

Sodium-containing intercalates having as general formula Na _x VOPOP₄·(2–x)H₂O (0.25x<0.50) have been obtained and characterized. Orthorhombic phases, which essentially maintain the structure of the layered oxide hydrate VOPO₄·2H₂O result. Intercalated sodium ions act as pillars. The presence of H₃O⁺ ions in the parent VOPO₄·2H₂O and also in some reduced phases, is detected. The understanding of the structural role of the water molecules is advanced and the topotactic dehydration/rehydration processes are studied. The formation of a new metastable VOPO₄·H₂O phase is established.     

Zr2N2Se: The First Zirconium(IV) Nitride Selenide by the Oxidation of Zirconium(III) Nitride with Selenium

The oxidation of zirconium(III) nitride (ZrN) with suitable amounts of selenium (Se) in the presence of sodium chloride (NaCl) as flux yields small yellow brownish platelets of the first zirconium(IV) nitride selenide with the composition Zr₂N₂Se. The new compound crystallizes in the hexagonal space group P6₃/mmc (no. 194) with a = 363.98(2) pm, c = 1316.41(9) pm (c/a = 3.617) and two formula units per unit cell. The crystallographically unique Zr⁴⁺ cations are surrounded by three selenide and four nitride anions in the shape of a capped trigonal antiprism. The Se^2– anions are coordinated by six Zr⁴⁺ cations as trigonal prism and the N^3– anions reside in tetrahedral surrounding of Zr⁴⁺ cations. These [NZr₄]¹³⁺ tetrahedra become interconnected via three edges each to form $\rm^{2}_{\infty}$ {[(NZr_4/4)₂]²⁺} double layers parallel to the (001) plane, which are held together by monolayers of Se^2– anions.