AgCo3PO4(HPO4)2

The structure of the hydro­thermally synthesized compound AgCo₃PO₄(HPO₄)₂, silver tricobalt phosphate bis­(hydrogen phosphate), consists of edge‐sharing CoO₆ chains linked together by the phosphate groups and hydrogen bonds. The three‐dimensional framework delimits two types of tunnels which accommodate Ag⁺ cations and OH groups. The title compound is isostructural with the compounds AM₃H₂(XO₄)₃ (A = Na or Ag, M = Co or Mn, and X = P or As) of the alluaudite structure type.     

Crystal structure of a new complex of [3-(1 H -benzimidazol-yl)propionato- N ][3-(1 H -benzimidazol-yl) propionic acid- N ]silver(I), C20H19AgN4O4

The silver and acid hydrogen atoms in the crystal structure of [Ag(pa)(Hpa)] _n (Hpa?=?3-(1H-benzimidazol-2-yl) propionic acid-N) both lie on special positions of ?1 site symmetry; the silver atom shows linear coordination [Ag–N?=?2.109(3)?Å, N–Ag–N?=?180°]. The ‘acid hydrogen’ links molecules into a linear chain, and hydrogen bonds between the nitrogen-bound hydrogen atom and the carbonyl oxygen atom of an adjacent chain furnish a three-dimensional supramolecular structure. The compound, C₂₀H₁₉AgN₄O₄, belongs to the triclinic space group P 1 [a?=?6.536(7), b?=?8.127(9), c?=?9.051(1)?Å; α?=?81.692(2), β?=?82.819(2), γ?=?87.229(2)°], and there is one formula unit in the unit cell.     

β‐LiMoO2(AsO4)

A new non‐centrosymmetrical form of lithium molybdyl arsenate has been synthesized and grown as a single crystal. The structure of β‐LiMoO₂(AsO₄) is built up of corner‐sharing AsO₄ tetrahedra and MoO₆ octahedra which form a three‐dimensional framework containing tunnels running along the a axis, wherein the Li⁺ cations are located. This novel structure is compared with the compound LiMoO₂(AsO₄) of the same formula, and with those of AMO₂(XO₄) (A is Na, K, Rb or Pb, M is Mo or V, and X is P or As) and B(MoO₂)₂(XO₄)₂ (B is Ba, Pb or Sr).     

β‐Tl2SO4

The ambient‐temperature form of dithallium sulfate, β‐Tl₂SO₄, is similar to β‐K₂SO₄ and is characterized by isolated sulfate tetrahedra and two different thallium sites with coordination numbers 9 and 11. All the atoms, except one O atom, lie on mirror planes. In spite of there being a high concentration of Tl⁺ cations, the stereochemical activity of the 6s² pairs is low, similar to that of isotypic Tl₂XO₄ compounds (X = Cr and Se). This behaviour is the consequence of both weak Tl—O bonds and strong X—O bonds, because in a Tl—O—X linkage the electronic cloud of the O²⁻ anion is strongly distorted and displaced towards X, resulting in a low negative charge in the face of the Tl atom. Consequently, the Coulombic repulsions between the lone pair and the O²⁻ anions are weak. All of the Tl₂XO₄ compounds exhibit the same open packing of A⁺ cations and [XO₄]²⁻ anions as their isotypic alkali counterparts.     

Centrosymmetric aliovalent KTP isomorphs KMIII0.5Nb0.5OPO4 (M = Cr and Fe)

Aliovalent KTP isomorphic compounds potassium chromium niobium oxide phosphate, KCr_0.5Nb_0.5OPO₄, and potassium iron niobium oxide phosphate, KFe_0.5Nb_0.5OPO₄, exhibit structures that differ from that of the non‐centrosymmetric KTiOPO₄. There are two crystallographically independent octa­hedral sites, M1 and M2, statistically occupied by Nb and Cr (or Fe) atoms. The M1O₆ and M2O₆ octa­hedra are connected alternately to form a chain with a cis–trans arrangement. The Nb atoms prefer the M2 sites arranged in a cis‐like configuration. Each PO₄ tetra­hedon has the P atom on a twofold axis. Site‐splitting at the K‐atom position is observed in both compounds. In the isomorphous structures, one Nb atom lies on an inversion centre and the other on a twofold axis. Similarly with the pairs of Fe/Cr sites, one is on an inversion centre and the other on a twofold axis.     

Counter‐anion role in the formation of two supramolecular complexes: [Ag2(DPP)2](ClO4)2·CH3CN and [Ag2(DPP)2(NO3)2] {DPP is N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine}

The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag₂(C₁₈H₁₇N₂P)₂](ClO₄)₂·CH₃CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}bis[(nitrato‐κ²O,O)silver], [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂], (2), each contain disilver macrocyclic [Ag₂(C₁₈H₁₇N₂P)₂]²⁺ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag⁺ cations in a head‐to‐tail fashion. In (1), the unique Ag⁺ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO₄⁻ anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C₁₈H₁₇N₂P)]⁺ cations. The nitrate anions weakly chelate to each Ag⁺ cation, leading to each Ag⁺ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.     

The crystal structure of NaAs4O6Br

The crystal structure of NaAs₄O₆Br [a = 5.237(1), B = 8.043(1), C = 18.978(2) Å; space group Pmcn-D¹⁶_2h; Z = 4] was solved by a direct method strategy and was refined to an R value of 0.038 for 1515 intensities and 68 variables. The structure is characterized by neutrally charged and slightly waved As₂O₃ sheets arranged parallel to (001). These sheets are combined by the Na and Br atoms. The Na atom is coordinated to nine oxygen atoms and one bromine atom and the Br atom is coordinated to six arsenic atoms and one sodium atom. The compound NaAs₄O₆Br was synthesized by thermal treatment of NaBr and As₂O₃ in methanol solution [400(5) K, saturation vapor pressure].     

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.     

catena‐Poly­[[(di‐2‐pyridyl­amine)­silver(I)]‐μ‐nicotinato] and catena‐poly­[[(di‐2‐pyridyl­amine)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato]

In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐nico­tinato‐κ²N:O], [Ag(C₆H₄NO₂)(C₁₀H₉N₃)]_n, the Ag^I atom is tetracoordinated by two N atoms from the di‐2‐pyridyl­amine (BPA) ligand [Ag—N = 2.3785 (18) and 2.3298 (18) Å] and by one N atom and one carboxyl­ate O atom from nicotinate ligands [Ag—N = 2.2827 (15) Å and Ag—O = 2.3636 (14) Å]. Bridging by nicotinate N and O atoms generates a polymeric chain structure, which extends along [100]. The carboxyl O atom not bonded to the Ag atom takes part in an intrachain C—H⋯O hydrogen bond, further stabilizing the chain. Pairs of chains are linked by N—H⋯O hydrogen bonds to generate ribbons. There are no π–π interactions in this complex. In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato‐κ²O¹:O²], [Ag(C₇H₅O₄)(C₁₀H₉N₃)]_n, the Ag^I atom has a distorted tetrahedral coordination, with three strong bonds to two pyridine N atoms from the BPA ligand [Ag—N = 2.286 (5) and 2.320 (5) Å] and to one carboxyl­ate O atom from the 2,6‐di­hydroxy­benzoate ligand [Ag—O = 2.222 (4) Å]; the fourth, weaker, Ag‐atom coordination is to one of the phenol O atoms [Ag⋯O = 2.703 (4) Å] of an adjacent moiety, and this interaction generates a polymeric chain along [100]. Pairs of chains are linked about inversion centers by N—H⋯O hydrogen bonds to form ribbons, within which there are π–π interactions. The ribbons are linked about inversion centers by pairs of C—H⋯O hydrogen bonds and additional π–π interactions between inversion‐related pairs of 2,6‐di­hydroxy­benzoate ligands to generate a three‐dimensional network.     

Synthesis and Structure of the First Three‐legged Low‐dimensional Iron Phosphate, [H3N(CH2)3NH2(CH2)2NH2(CH2)3NH3][Fe3F6(HPO4)2(PO4)]·3H2O

A hydrothermal reaction of iron acetylacetonate, phosphoric acid, HF, N, N′‐bis(3‐aminopropyl)ethylenediamine and water at 150 °C gave rise to a new iron phosphate, [H₃N(CH₂)₃NH₂(CH₂)₂NH₂(CH₂)₃NH₃][Fe₃F₆(HPO₄)₂(PO₄)] · 3H₂O ( I ). The structure consists of Fe(1)O₄F₂, Fe(2)O₃F₃ octahedral and P(1)O₃(OH) and P(2)O₄ tetrahedral building units connected through their vertices to form fragments of tancoite‐type units. The tancoite‐type units are linked through the phosphate tetrahedra forming an unusual iron phosphate with a hitherto unknown low‐dimensional structure with three‐iron center.Magnetic studies indicate a complex behavior at low temperature and the high‐temperature data (150 — 300 K) has a Curie‐Weiss behavior. The calculated room temperature magnetic moment is 6 μ_B per Fe atom, and the Neel temperature, T_N = 46K. Crystal data: orthorhombic, space group = I2₁2₁2₁ (no. 24), a = 9.9042(11), b = 12.8865(14), c = 19.783(2)Å, U = 2524.9(5), Z = 4.     

Poly[[diaquabis(μ2‐1‐oxo‐2,6,7‐trioxa‐1‐phosphabicyclo[2.2.2]octane‐4‐carboxylato)copper(II)] dihydrate]

The asymmetric unit of the title complex, {[Cu(C₅H₆O₆P)₂(H₂O)₂]·2H₂O}_n, consists of half a Cu atom, one complete 1‐oxo‐2,6,7‐trioxa‐1‐phosphabicyclo[2.2.2]octane‐4‐carboxylate anion ligand and two non‐equivalent water molecules. The Cu atom lies on a crystallographic inversion centre and has an elongated axially distorted octahedral environment. A two‐dimensional layer structure parallel to (100) is formed as a result of the connectivity brought about by each anion bonding to two different Cu atoms via a carboxylate O atom and a bridging O atom of a C—O—P group. The water molecules participate in extensive O—H...O hydrogen bonding. Neighbouring layers are linked together by intermolecular hydrogen‐bonding interactions. The crystal structure is characterized by intra‐ and interlayer motifs of a hydrogen‐bonded network. This study demonstrates the usefulness of carboxylates with caged phosphate esters in crystal engineering.     

Untersuchungen über Zinn(IV)-alkoxide. I Kristall- und Molekülstruktur des Zinn(IV)-isopropanolat-Isopropanolsolvats,Sn(OiPr)4 · i-PrOH

Investigations into Tin(IV) Alkoxides. I. Crystal and Molecular Structure of Tin(IV)-isopropoxide-Isopropanol Solvate, Sn(OⁱPr)₄ · i-PrOH The isopropanol complex of tin(IV)-isopropoxide has been prepared by the reaction of tin tetrachloride with sodium isopropoxide. The compound forms colourless, moisture sensitive crystals, which in dry air easily release the coordinated solvent molecules. The crystal and molecular structure of Sn(OⁱPr)₄ · i-PrOH has been determinated by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/c with a = 1174.2(5), b = 1428.5(3), c = 1234.1(3) pm, β = 95.37(1)° and Z = 4. The crystal structure consists of discrete, dimeric molecules in which the two tin atoms are bridged by two alkoxide groups. The octahedral coordination sphere of each tin atom is completed by one solvent molecule which, in addition, forms one hydrogen bridge to an alkoxide group of the neighboring tin atom.     

Synthesis,crystal structures and properties of the new compounds K7–xAg1+x(XO4)4 (X = Mo,W)

Two new isostructural compounds, namely heptapotassium silver tetrakis(tetraoxomolybdate), K_7–x Ag_1+x (MoO₄)₄ (0 ≤ x ≤ 0.4), and heptapotassium silver tetrakis(tetraoxotungstate), K_7–x Ag_1+x (WO₄)₄ (0 ≤ x ≤ 0.4), have been synthesized and found to crystallize in the polar space group P 6₃mc (Z = 2) with the unit‐cell dimensions a = 12.4188 (2) and c = 7.4338 (2) Å for K_6.68Ag_1.32(MoO₄)₄ (single‐crystal data), and a = 12.4912 (5) and c = 7.4526 (3) Å for K₇Ag(WO₄)₄ (Rietveld analysis data). Both structures represent a new structure type, with characteristic [K1(X O₄)₆] `pinwheels' of K1O₆ octahedra and six X O₄ tetrahedra (X = Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are linked to each other through Ag1O₄ tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (…Ag1O₄–X 1O₄–empty octahedron–Ag1O₄…). Ag1 is located almost at the centre of the largest face of its coordination tetrahedron and seems to have some mobility. The new structure type is related to the Ba₆Nd₂Al₄O₁₅ and CaBaSiO₄ types, and to other structures of the α‐K₂SO₄–glaserite family. The differential scanning calorimetry (DSC) and second harmonic generation (SHG) results show that both compounds undergo first‐order phase transformations to high‐temperature centrosymmetric phases.     

Tetra­kis(μ2‐1,8‐naphthyridine)‐1:2κ4N:N′;3:4κ4N:N′‐bis­(μ2‐salicylato)‐1:4κ2O:O′;2:3κ2O:O′‐tetrakis­(salicylic acid)‐1κO,2κO,3κO,4κO‐tetra­silver(I)(4 Ag—Ag)

The title complex, [Ag₄(C₇H₅O₃)₂(C₈H₆N₂)₄(C₇H₆O₃)₄], lies about an inversion centre and has a unique tetra­nuclear structure consisting of four Ag^I atoms bridged by four N atoms from two 1,8‐naphthyridine (napy) ligands to form an N:N′‐bridge and four O atoms from two salicylate (SA) ligands to form an O:O′‐bridge. The Ag atoms have distorted octa­hedral coordination geometry. The centrosymmetric Ag₄ ring has Ag—Ag separations of 2.772 (2) and 3.127 (2) Å, and Ag—Ag—Ag angles of 107.70 (4) and 72.30 (4)°. All SA hydroxy groups take part in intra­molecular O—H⋯O hydrogen bonding. In the crystal packing, the napy rings are oriented parallel and overlap one another. These π–π inter­actions, together with weak inter­molecular C—H⋯O contacts, stabilize the crystal structure.     

A new whitlockite,Ca8.42Na1.16V(PO4)7

Single crystals of a new complex phosphate, calcium sodium vanadium phosphate, Ca_8.42Na_1.16V(PO₄)₇, have been grown from a melt under an inert atmosphere. The crystal structure has rhombohedral (R3c) symmetry and belongs to the whitlockite structure type. Vanadium(III) ions occupy nearly regular octa­hedral sites (M5 with 3 point symmetry), which share corners with six PO₄ tetra­hedra to form isolated units. The calcium ions occupy eight‐ and nine‐coordinated sites. The sodium ions partially occupy one octa­hedral position and share one nine‐coordinated position with a Ca atom.     

Oxygen‐Atom Transfer Chemistry and Thermolytic Properties of a Di‐tert‐Butylphosphate‐Ligated Mn4O4 Cubane

[Mn₄O₄{O₂P(OtBu)₂}₆] ( 1 ), an Mn₄O₄ cubane complex combining the structural inspiration of the photosystem II oxygen‐evolving complex with thermolytic precursor ligands, was synthesized and fully characterized. Core oxygen atoms within complex 1 are transferred upon reaction with an oxygen‐atom acceptor (PEt₃), to give the butterfly complex [Mn₄O₂{O₂P(OtBu)₂}₆(OPEt₃)₂]. The cubane structure is restored by reaction of the latter complex with the O‐atom donor PhIO. Complex 1 was investigated as a precursor to inorganic Mn metaphosphate/pyrophosphate materials, which were studied by X‐ray absorption spectroscopy to determine the fate of the Mn₄O₄ unit. Under the conditions employed, thermolyses of 1 result in reduction of the manganese to Mn^II species. Finally, the related butterfly complex [Mn₄O₂{O₂P(pin)}₆(bpy)₂] (pin=pinacolate) is described.     

Enhanced Visible Light Irradiation Photocatalytic Performance of MgFe2O4 After Growing with ZnO Nanoshell and Silver Nanoparticles

MgFe₂O₄ implanted with ZnO and silver nanoparticles has been successfully synthesized. The formation mechanism of the core~shell structured Ag/ZnO /MgFe₂O₄ nanoparticles was investigated. The efficacy of degradation of an organic dye was compared under the visible light irradiation with the individual components (MgFe₂O₄ , ZnO , and Ag). The structure of Ag/ZnO /MgFe₂O₄ nanoparticles was established from detailed structural analyses using a vibrating‐sample magnetometer (VSM), X‐ray diffraction (XRD ), selected area electron diffraction (SAED ), scanning electron microscopy (SEM ), energy‐dispersive X‐ray spectroscopy (EDS ), and transmission electron microscopy (TEM ). Ag/ZnO /MgFe₂O₄ nanoparticles showed a saturation magnetization (M _s) of 44 emu/g. It is seen from the results that ZnO is coated on the surface of MgFe₂O₄ nanoparticles, and Ag nanoparticles are attached to the edge of the ZnO /MgFe₂O₄ nanoparticles. In addition, the nanoparticles were found to be spherical with appropriate structures. The electron transfer mechanism greatly enhances the rhodamine B (RhB ) degradation rate, which is illustrated and discussed in detail. The obtained Ag/ZnO /MgFe₂O₄ nanoparticles were photostable and magnetically recyclable with potential application in the degradation of organic pollutants.     

CsAlZr2(PO4)4: an anhydrous aluminium zirconium phosphate with a novel three‐dimensional framework

Caesium aluminium dizirconium tetrakis[phosphate(V)], CsAlZr₂(PO₄)₄, has been synthesized by high‐temperature reaction and studied by single‐crystal X‐ray diffraction at room temperature. This represents the first detailed structural analysis of an anhydrous phosphate containing both zirconium and aluminium. The structure features a complicated three‐dimensional framework of [AlZr₂(PO₄)₄] constructed by PO₄, AlO₄ and ZrO₆ polyhedra interconnected via corner‐sharing O atoms, and one‐dimensional Cs chains which are located in the infinite tunnels within the [AlZr₂(PO₄)₄] framework, which run along the c axis. The Cs, Al, one P and two O atoms lie on a mirror plane, while a second P atom lies on a twofold axis.     

Novel Copper(I) Clusters with 2‐(Diphenylphosphanyl)anilide Ligands. Synthesis and Crystal Structures of [Cu6X2(NHR)4] (X = Cl,Br, I; R = C6H4‐2‐PPh2)

Treatment of copper(I) halides CuX (X = Cl, Br, I) with lithium 2‐(diphenylphosphanyl)anilide [Li(HL)] in THF led to the formation of hexanuclear copper(I) complexes [Cu₆X₂(HL)₄] [X = Cl ( 1 ), Br ( 2 ), I ( 3 )]. In compounds 1 – 3 , the copper atoms are in a distorted octahedral arrangement and the amide ligands adopt a μ₃‐κP,κ²N bridging mode. Additionally there are two μ₂‐bridging halide ligands. Each of the [Cu₆X₂(HL)₄] clusters comprises two copper atoms, which are surrounded by two amide nitrogen atoms in an almost linear coordination [Cu–N: 186.2(3)–188.0(3) pm] and four copper atoms, which are connected to an amide N atom, a P atom, and a halogen atom in a distorted trigonal planar fashion [Cu–N: 199.6(3)–202.3(3) pm)].     

A two‐dimensional silver(I) coordination polymer constructed from 4‐aminophenylarsonate and triphenylphosphane: poly[[(μ3‐4‐aminophenylarsonato‐κ3N:O:O)(triphenylphosphane‐κP)silver(I)] monohydrate]

The title compound, {[Ag(C₆H₇AsNO₃)(C₁₈H₁₅P)]·H₂O}_n, has been synthesized from the reaction of 4‐aminophenylarsonic acid with silver nitrate, in aqueous ammonia, with the addition of triphenylphosphane (PPh₃). The Ag^I centre is four‐coordinated by one amino N atom, one PPh₃ P atom and two arsonate O atoms, forming a severely distorted [AgNPO₂] tetrahedron. Two Ag^I‐centred tetrahedra are held together to produce a dinuclear [Ag₂O₂N₂P₂] unit by sharing an O–O edge. 4‐Aminophenylarsonate (Hapa⁻) adopts a μ₃‐κ³N:O:O‐tridentate coordination mode connecting two dinuclear units, resulting in a neutral [Ag(Hapa)(PPh₃)]_n layer lying parallel to the (10) plane. The PPh₃ ligands are suspended on both sides of the [Ag(Hapa)(PPh₃)]_n layer, displaying up and down orientations. There is an R₂²(8) hydrogen‐bonded dimer involving two arsonate groups from two Hapa⁻ ligands related by a centre of inversion. Additionally, there are hydrogen‐bonding interactions involving the solvent water molecules and the arsonate and amine groups of the Hapa⁻ ligands, and weak π–π stacking interactions within the [Ag(Hapa)(PPh₃)]_n layer. These two‐dimensional layers are further assembled by weak van der Waals interactions to form the final architecture.