Subtle difference of [SiMo12O40]4− and [PMo12O40]3− inducing two new distinct Keggin-Ag-(1H-Pyrazole) compounds

Two new inorganic-organic hybrid compounds based on α-Keggin clusters and Ag-(1H-Pyrazole) subunits, [AgL₂]₄[SiMo₁₂O₄₀] (1) and [AgL₂]₃[PMo₁₂O₄₀] (2) (L = pyrazole), have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction. In 1, there are two kinds of chains, the chains linked by two [AgL₂]⁺ clusters and the other linked only by one [AgL₂]⁺, which further connect by sharing [SiMo₁₂O₄₀]^4? anions to construct a 2-D layer. In 2, four-supporting [PMo₁₂O₄₀]^3? anions are fused by [Ag(1)L₂]⁺ subunits to form a 1-D chain. Through weak interactions of Ag?O (3.091 Å) a 2-D supramolecular layer is constructed. Additionally, the electrochemical properties of title compounds and the photocatalytic properties of 2 have been studied.     

Fluorinated Mono and Spirocyclic Δ5[sgrave]5P and Δ5[sgrave]6P Derivatives of (HO)3−nHnPO (n= 0−3)

Abstract

The properties of PF₅, HPF₄, H₂PF₃, and H₃PF₂ (Δ⁵[sgrave]⁵P derivatives of (HO)₃PO, (HO)₂HPO, (HO)H₂PO, and of the hypothetic H₃PO) and the formation of the related Δ⁵[sgrave]⁶P anions PF₆ ^–, HPF₅ ^–, and trans-H₂PF₄ ^– have been studied some years ago ^1–4. The mono and spirocyclic dioxa and tetraoxa analogues, 1 and 2 available from the corresponding precursor phosphoranes by fluoride addition could be found also as products in the reaction of phosphite 3⁵ and K⁺(CF₃)₂CFO^– together with two other phosphates, 4 and 5. A ¹⁹F–¹⁹F homocorrelated 2 D NMR spectrum of 2 indicated coupling of the P–F fluorine nuclei with two CF₃ groups by a non bond mechanism.     

Two new supramolecular compounds based on Ni(II)-Schiff-base and Keggin-type [PMo12O40]3−

Two polyoxometalate-templated nickel-Schiff-base compounds, {[Ni(L)₂]₂[PMo₁₂O₄₀][Cl] · 1.5DMF · H₂O} _n (1) and {[Ni(L)₂]₂[PMo₁₂O₄₀][Cl] · DMSO · CH₃OH · 0.5H₂O} _n (2) (where L is 1,4-bis(4-imidazolyl)-2,3-diaza-1,3-butadiene), were synthesized in situ from Ni²⁺ and L in H₂O/DMF/CH₃OH or H₂O/DMSO/CH₃OH at room temperature and characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. The results of the single-crystal X-ray diffractions suggested that both compounds have the same packing of the Ni(II)-Schiff-base cation layer and Keggin anion layer. Thermogravimetric analyses suggested that two supramolecular compounds have similar thermal stabilities based on the same packing of the cation and anion layers.     

A new supramolecular compound based on Mn(II)-Schiff-base and Keggin-type [PMo12O40]3−

A new organometallic-inorganic hybrid compound {[Mn(L)₂]₂[PMo₁₂O₄₀][NO₃] · 4CH₃OH · 3H₂O} _n (I), where L is 1,4-bis(4-imidazolyl)-2,3-diaza-1,3-butadiene) was synthesized in situ from [PMo₁₂O₄₀]^3?, Mn²⁺ and L reaction in an H₂O-DMSO-CH₃OH mixture at room temperature, and the product was structurally characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. Compound I is constructed from alternating layers of the metal-Schiff-base cation and Keggin anions based on electrostatic forces and hydrogen bond interactions.     

Pressure tuning spectroscopy of [Pt3(CO)6]2−n (n=3–5)

The pressure shifts of the first three bands appearing in the visible spectra of [Pt₃(CO)₆]²⁻_n (n = 3–5) have been measured in solution over the range 0–10 kbar. Previous electronic calculations performed on the dimer in conjunction with these results afford a possible set of assignments for the first three bands appearing in the visible spectrum for the dimer.     

Formation of [FeW12O40]5− under hydrothermal conditions: syntheses,crystal structures,and characterization of [Fe(2,2′-bipy)3]2[HFeW12O40] · 5H2O and (4,4′-H2bipy)6(Hpy)2(H3O)[FeW12O40]3 · 11H2O

Two supramolecular compounds based on tungstoferrate [FeW₁₂O₄₀]^5?, [Fe^II(2,2′-bipy)₃]₂[HFeW₁₂O₄₀] · 5H₂O (1), and [Hpy]₂[4,4′-H₂bipy]₆(H₃O)[FeW₁₂O₄₀]₃ · 11H₂O (2) (py = pyridine, bipy = bipyridine) were synthesized hydrothermally and characterized structurally. The hydrogen bonds between polyoxoanions and water and the edge-to-face π–π interaction between [Fe^II(2,2′-bipy)₃]²⁺ with a shortest C–C distance of 3.513 Å are the main forces to construct the 3-D architecture of 1. In 2, a 3-D supramolecular architecture is assembled by the tungstoferrate anions, protonated 4,4′-bipy cations, and water through hydrogen bonding. The variable-temperature magnetic susceptibilities indicate that 1 is paramagnetic with μ _eff corresponding to one Fe(III) with spin-only contribution, showing that Fe in the coordination cations has a +II oxidation number and low spin state.     

Two new organic-inorganic hybrid compounds induced by γ-[Mo8O26]4− and [PMo12O40]3−

Two new organic–inorganic hybrid compounds, [Cu^II(btb)_1.5(γ-Mo₈O₂₆)_0.5(H₂O)]·2H₂O (1) and [Cu^II₂(btb)₄(PMo^VMo^VI₁₁O₄₀)]·2H₂O (2) (btb = 4-butyl-1,4-bis(1,2,4-triazole), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, IR spectra and elemental analyses. In 1, there exists a ladder-like metal-organic chain with the bidentate [γ-Mo₈O₂₆]^4? anions inserting into the grids. Adjacent chains share the same Cu-btb lines of the ladder to form a 2-D layer. Compound 2 also has a ladder-like metal-organic chain. The tetradentate [PMo₁₂O₄₀]^3? anions embed in the grids. The same Cu-btb line is shared by adjacent chains to build a 2-D layer. The btb ligands link adjacent layers to form a 3-D framework. Moreover, we also have investigated the electrochemical and photocatalytic properties of 1 and 2.     

New methods of preparation of hydroxy-closo-decaborates [B10H10 − n (OH) n ]2− (n = 1, 2)

New methods of preparation of hydroxy-closo-decaborates [B₁₀H_{10 ? n} (OH) _n ]^2? (n = 1, 2) that are based on the reaction of anions [B₁₀H_{10 ? n} (OAc) _n ]^2? and alkoxyethylidenoxonio-closo-decaborates [2-B₁₀H₉OC(OR)CH₃]^? with aqueous solution of hydrazine are proposed. The obtained compounds were characterized by IR, ESI/MS, and NMR (¹H, ¹¹B, ¹³C) spectroscopy.     

Negative ion photoelectron spectroscopy of solvated electron cluster anions, (H2O) n − and (NH3) n −

The photodetachment spectra of (H₂O) _n ^=2?69/? and (NH₃) _n ^=41?1100/? have been recorded, and vertical detachment energies (VDEs) were obtained from the spectra. For both systems, the cluster anion VDEs increase smoothly with increasing sizes and most species plot linearly withn ^?1/3, extrapolating to a VDE (n=∞) value which is very close to the photoelectric threshold energy for the corresponding condensed phase solvated electron system. The linear extrapolation of this data to the analogous condensed phase property suggests that these cluster anions are gas phase counterparts to solvated electrons, i.e. they are embryonic forms of hydrated and ammoniated electrons which mature with increasing cluster size toward condensed phase solvated electrons.     

The bis(ethylene)-dithiotetrathiafulvalene radical salt of [PVMo11O40]4−

The charge transfer salt, (ET)5PVMo11O40·2H2O [ET=bis(ethylene)-dithiotetrathiafulvalene], was prepared by reducing the diamagnetic molybdovanadophosphoric heteropoly acid (H4PMo11VO40·nH2O, HMVP) with the organic donor ET. The u.v.-vis spectrum of the complex shows an electronic transfer band at 900nm. The i.r. and Raman spectra suggest that the ET donor molecules are all completely ionized. Magnetic measurements indicate the presence of antiferromagnetic interactions in the ET organic sublattice. The e.s.r. spectrum exhibits a VIV signal with g=1.9718 and a=57.5cm–1. Over the measured temperature range (75–300K), no significant interaction between the paramagnetic anion and the organic radical cation is observed.     

Halide substitutions in the [Rh2(O f2 p− )(OH)2(H2O) n ]3+ complex

Summary Transition metal complexes containing activated dioxygen continue to attract considerable attention and are widely used as models, either as oxygen carriers or as catalysts in biological and industrial oxidations ^(1,2).Cobalt complexes containing the coordinated O₂ molecule are well known^(3,4), but the rhodium analogues are rare^(5–8). The known complexes with coordinated O₂ are rhodium(III) compounds containing strong nitrogen donor ligands.Our recent studies have focused on a synthesis of dioxygen rhodium derivatives in which a superoxide anion (O _f2 ^p– ) is bound to the [Rh^III—Rh^III] core surrounded by other donor molecules, e.g. H₂O, RCO _f2 ^p– (7,8), to investigate the effect of a coordination sphere of the metal centre on the redox properties of the O _f2 ^p– radical combined to it⁽⁹⁾.The [Rh₂(O _f2 ^p– )(OH)₂(H₂O) _n ]³⁺ cation, the product of oxidative addition of dioxygen to the [Rh₂(H₂O)₁₀]⁴⁺ dimer, was isolated by us and examined in aqueous HC1O₄ ^(7,9). So far we have been unable to isolate its solid but the water molecules coordinated to the [Rh₂(O _f2 ^p– )-(OH)₂] ³⁺ moiety were found to undergo substitution relatively easily⁽⁸⁾.     

Polymeric (NO)3(N2O) n , (NO)3(N2O) n + , and (NO)3(N2O) n − : an interpretation of experimental observations

Semi-empirical and ab initio calculations are reported which provide a possible explanation for reported experimental results on 2-photon ionization of NO containing a few percent of N₂O, which found (NO)₃(N₂O) _n ^+or? clusters to be significantly more abundant than other (NO) _m (N₂O) _n products. It is found that the observed abundances of (NO)₃(N₂O) _n ionic clusters may be accounted for by the existence of covalent cyclic trimers of nitric oxide attached to oligomers of nitrous oxide. The extra stability of NO trimers in the observed clusters appears to arise from (NO) ₃ ⁺ rather than (NO)₃. Attachment of an (N₂O) _n side chain to (NO) ₃ ⁺ occurs exothermically. It is suggested that the addition of N₂O to cyclic-(NO) ₃ ⁺ might provide a means of making a polymer of nitrous oxide, which could have useful properties.     

Interpretation der Absorptionsspektren der Komplexionen [Mo(CN)8]4−, [Mo(CN)8]3−, [W(CN)8]4− und [W(CN)8]3−

Zusammenfassung Die Absorptions- und Reflexionsspektren der Oktocyanokomplexe desMo(IV) undW(IV) sowie die Absorptionsspektren der Oktocyanotomplexe desMo(V) undW(V) werden mitgeteilt. Die Spektren werden unter Zugrundelegung der durch Raman- und IR-spektroskopische Untersuchungen gefordertenD _4d-Symmetrie dieser Verbindungen interpretiert. Die beobachteten Banden niedriger Intensität (log<3) werden Übergängen in einem Termsystem zugeordnet, das für die Konfigurationend ² undd ₁ und die SymmetrieD _4d berechnet worden ist. Banden hoher Intensität (log>3) werden auf Übergänge in antibindende Zustände zurückgeführt, an denen höherep-Zustände des Zentralions sowie Ligandenzustände beteiligt sind. Die erhaltenen Werte des Feldparameters stimmen mit ligandenfeldtheoretischen Erwartungen überein.

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Absorption and reflection spectra of the octacyanides ofMo(IV) andW(IV) and the absorption spectra of the octacyanides ofMo(V) andW(V) are presented. The spectra are interpreted in terms of theD _4d symmetry of the compounds supported by investigations of Raman and infrared spectra. Bands of low intensity (log<3) correspond to transitions between levels obtained in the case of the configurationsd ² andd ¹ respectively, in a field ofD _4d symmetry. Bands of high intensity (log>3) are attributed to transitions into antibonding levels in which p-orbitals of the central ion and ligand orbitals participate. The values of the field parameter obtained are in accord with ligand field theory.

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Résumé Les spectres d'absorption et de réflexion des complexes octocyanurés duMo(IV) et duW(IV) ainsi que les spectres d'absorption des mêmes complexes deMo(V) et de W(V) sont présentés. Les spectres sont interprétés en supposant la symétrieD _4d des molécules indiquée par des analyses des spectres Raman et infrarouges. Les bandes de faible intensité (log<3) sont attribuées à des transitions dans un système de niveaux, calculé pour les configurationsd ² etd ¹, respectivement, en symétrieD _4d. Des bandes de forte intensité (log>3) sont attribuées à des transitions vers des niveaux antiliants auxquels participent des fonctions élevéesp de l'ion central et des fonctions des groupes liés. Les valeurs obtenues pour le paramètre de champ sont en accord avec les prévisions de la théorie.

     

Stabilization and Binding of [V4O12]4− and Unprecedented [V20O54(NO3)]n− to Lysozyme upon Loss of Ligands and Oxidation of the Potential Drug VIVO(acetylacetonato)2

High-resolution crystal structures of lysozyme in the presence of the potential drug V^IVO(acetylacetonato)₂ under two different experimental conditions have been solved. The crystallographic study reveals the loss of the ligands, the oxidation of V^IV to V^V and the subsequent formation of adducts of the protein with two different polyoxidovanadates: [V₄O₁₂]⁴⁻, which interacts with lysozyme non-covalently, and the unprecedented [V₂₀O₅₄(NO₃)]ⁿ⁻, which is covalenty bound to the side chain of an aspartate residue of symmetry related molecules.     

hree Inorganic-organic Composite Polyoxotungstates:Syntheses, Characterization and Structures of [Cu(2,2'-bpy)2]5[α-PW11.5Cu0.5O40]·2H2O,[Co(2,2'-bpy)2(N3)2]4H3[α-PW12O40]·3H2O and [Cu(2,2'-bpy)2(4,4'-bpy)]2[α-GeW12O40]·4H2O

Three new inorganic-organic composite polyoxotungstates [Cu(2,2'- bpy)2]5[α- PW11.5Cu0.5O40]·2H2O 1, [Co(2,2'-bp3)2(N3)2]4H3[α-PW12O40]·3H2O 2 and [Cu(2,2'-bpy)2(4,4'- bpy)]2[α-GeW12O40].4H2O 3 (2,2'-bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the orthorhombie space group Pna21 with α = 27.847(3), b = 21.597(2), c = 20.1179(19) A, V = 12099(2) A3, Z = 4, GOF= 1.038, R = 0.0427 and wR = 0.1035; 2 belongs to the triclinic space group P1 with a= 12.31150(10), b = 16.1954(4), c = 19.36290(10) A, α = 99.366(11), β=105.168(8),γ = 111.836(8)°, V = 3309.98(9) A3, Z = 1, GOF = 1.024, R = 0.0739 and wR = 0.2216; and 3 crystallizes in the monoclinic space group P21/n with a = 12.858(4), b = 20.943(6), c = 15.598(5) A, β = 102.338(5)°, V = 4103(2) A3, Z = 2, GOF = 1.026, R = 0.0557 and wR = 0.1316. The common structural features of 1～3 are that their molecular structures all consist of a saturated a-Keggin polyoxoanion and several discrete metal-organic moieties. Intriguingly, 2 and 3 are composed of metal-organic coordination moieties with two mixed ligands.     

Framework polymers based on octahedral chalcocyanide cluster [Re6Q8(CN)6]4−/3− anions (Q = Se, Te) and [Nd(Bipy)n]3+ Complexes (n = 1, 2)

Interaction of salts of the cluster anions {Re [Re₆Q₈(CN)₆]^4?/3? (Q = Se, Te) with Nd salts in the presence of 2,2′-bipyridyl (Bipy) ligand brings about new coordination polymers: Pr ₄ ⁿ N[{Nd(Bipy)(H₂O)₄} {Re₆Se₈(CN)₆}] · 2H₂O (I) (space group C2/c, a = 18.2918(16) Å, b = 14.9972(13) Å, c = 37.513(3) Å, β = 102.046(4)°, V = 10064.2(15) ų, Z = 8), [{Nd(Bipy)₂(H₂O)} {Re₆Se₈(CN)₆}] (II) (space group C2/c, a = 15.8668(3) Å, b = 13.5403(3) Å, c = 20.5189(4) Å, β = 110.135(1)°, V = 4138.89(15) Å₃, Z = 4), and [{Nd(Bipy)(EtOH)(H₂O)₄}{Re₆Te₈(CN)₆}] · EtOH (III) (space group $P\bar 1$ , a = 9.4733(6) Å, b = 12.5326(8) Å, c = 17.2374(11) Å, α = 96.561(2)°, β = 90.310(2)°, γ = 94.876(2)°, V = 4138.89(15) Å₃, Z = 4). The compounds synthesized are characterized by single-crystal X-ray diffraction and IR methods. Compounds I and III have layered (2D) structures, compound II is a framework (3D) polymer.     

Synthesis and characterisation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−, [Q]2[Sn(dmit)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(dmio)3] and [tris(1,3-dithiole-2-thione-4,5-selenolato)stannate]2−, [Q]2[Sn(dsit)3], complexes: Analysis of the structural variations of the [Sn(dmit)3]2− and [Sn(dmio)3]2− dianions

[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₅)₃], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₄O)₃], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]²⁻ [Q]₂[Sn(C₃S₃Se₂)₃], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]₂[Sn(C₃S₅)₃] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe₄, NEt₄, and PPh₄) and [NEt₄]₂[Sn(C₃S₄O)₃] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe₄, in chains for the somewhat larger cation, NEt₄ and is absent for the still larger, PPh₄ cation.