Polymorph of {2‐[(2‐hydroxyethyl)iminiomethyl]phenolato‐κO}dioxido{2‐[(2‐oxidoethyl)iminomethyl]phenolato‐κ3O,N,O′}molybdenum(VI)

A second polymorphic form (form I) of the previously reported compound {2‐[(2‐hydroxyethyl)iminiomethyl]phenolato‐κO}dioxido{2‐[(2‐oxidoethyl)iminomethyl]phenolato‐κ³O,N,O′}molybdenum(VI) (form II), [Mo(C₉H₉NO₂)O₂(C₉H₁₁NO₂)], is presented. The title structure differs from the previously reported polymorph [Głowiak, Jerzykiewicz, Sobczak & Ziółkowski (2003). Inorg. Chim. Acta, 356 , 387–392] by the fact that the asymmetric unit contains three molecules linked by O—H...O hydrogen bonds. These trimeric units are further linked through O—H...O hydrogen bonds to form a chain parallel to the [11] direction. As in the previous polymorph, each molecule is built up from an MoO₂²⁺ cation surrounded by an O,N,O′‐tridentate ligand (O⁻C₆H₄CH=NCH₂CH₂O⁻) and weakly coordinated by a second zwitterionic ligand (O⁻C₆H₄CH=N⁺HC₂H₄OH). All complexes are chiral with the absolute configuration at Mo being C or A. The main difference between the two polymorphs results from the alternation of the chirality at Mo within the chain.     

Synthesis of {242}‐ and {323}‐p‐Octiphenyls

The introduction of rigid‐rod molecules as privileged scaffolds has opened routes to otherwise problematic supramolecular architecture like artificial β‐barrels and functional supramolecules covering pores, hosts, sensors, and catalysts. The usefulness of p‐oligophenyls for the construction of functional barrel‐stave architecture has, however, been limited by uniform substitution along the rigid‐rod scaffold. The objective of this report is to overcome this obstacle for the synthesis of p‐octiphenyls with orthogonally protected carboxylic acid groups along the rigid‐rod scaffold. In the reported {242}‐p‐octiphenyl 1 , the two peripheral arene moieties carry carboxylic acid groups protected as benzyl esters, whereas the four central carboxylic acid groups are protected orthogonally as tert‐butyl esters (Scheme 2). The complementary orthogonal protection of the three peripheral and the two central arenes is achieved in the {323}‐p‐octiphenyl 2 (Scheme 3). The realized {242}‐ and {323}‐p‐octiphenyls 1 and 2 , respectively, provide a complete set for the general access to refined rigid‐rod barrel‐stave architecture with maximized functional plasticity. The need for resolution‐enhanced (aliased) HMBC 2D‐NMR spectroscopy to characterize these refined oligomers is described in the following publication in this issue of Helv. Chim. Acta.     

{N‐[2‐(η5‐Cyclopentadienyl)ethyl]‐4‐toluenesulfonamido‐N,O}(tetrahydrofuran‐O)bis(trifluoromethanesulfonato‐O)titanium(II)

The title compound, [Ti(CF₃O₃S)₂(C₁₄H₁₅NO₂S)(C₄H₈O)], contains a unique ligand system in which the Ti ion is bound to the N and O atoms of a 2‐p‐toluene­sulfon­amide ligand, which is linked by an ethyl group to a coordinated cyclo­penta­diene moiety. The distorted octahedral geometry about the Ti ion is completed by two tri­fluoro­methane­sulfonate ligands and a tetra­hydro­furan mol­ecule. Comparison with related compounds shows that both the Ti—N and Ti—O bonds of the sulfon­amide, although longer than normal values, indicate significant bonding interactions.     

High Nuclearity Antimonato‐Polyoxovanadate Cluster {V15Sb6O42} as a Synthon for the Solvothermal in situ Generation of α‐ and β‐{V14Sb8O42} Isomers

New heteroatom polyoxovanadates (POVs) were synthesized by applying a water‐soluble high‐nuclearity cluster as new synthon. The [V₁₅Sb₆O₄₂]^6? cluster shell exhibiting D₃ symmetry was in situ transformed into completely different cluster shells, namely, the α‐[V₁₄Sb₈O₄₂]^4? isomer with D_2d and the β‐[V₁₄Sb₈O₄₂]^4? isomer with D_2h symmetry. The solvothermal reaction of {Ni(en)₃}₃[V₁₅Sb₆O₄₂(H₂O)_x] ? 15 H₂O (x=0 or 1; en=ethylenediamine) in water led to the crystallization of [{Ni(en)₂}₂V₁₄Sb₈O₄₂] ? 5.5 H₂O containing the β‐isomer. The addition of [Ni(phen)₃](ClO₄)₂ ? 0.5 H₂O (phen=1,10‐phenanthroline) to the reaction slurry gave the new compound {Ni(phen)₃}₂[V₁₄Sb₈O₄₂] ? phen ? 12 H₂O with the α‐isomer. Both transformation reactions are complex due the change of symmetry, the chemical composition, and rearrangement of the VO₅ square pyramids and Sb₂O₅ handle‐like moieties.     

Poly[(μ4‐adamantane‐1,3‐dicarboxylato‐κ5O1:O1′:O3,O3′:O3′)(μ3‐adamantane‐1,3‐dicarboxylato‐κ5O1,O1′:O3,O3′:O3′)dimagnesium]: a layered coordination polymer

The title compound, [Mg₂(C₁₂H₁₄O₄)₂]_n, is the first example of an s‐block metal adamantanedicarboxylate coordination polymer. The asymmetric unit comprises two crystallographically unique Mg^II centers and two adamantane‐1,3‐dicarboxylate ligands. The compound is constructed from a combination of chains of corner‐sharing magnesium‐centered polyhedra, parallel to the a axis, connected by organic linkers to form a layered polymer. The two Mg^II centers are present in distorted tetrahedral and octahedral coordination environments derived from carboxylate O atoms. Tetrahedrally coordinated Mg^II centers have been reported in organometallic compounds, but this is the first time that such coordination has been observed in a magnesium‐based coordination polymer. The bond valance sums of the two Mg^II centers are 2.05 and 2.11 valence units, matching well with the expected value of 2.     

Bis(μ‐3‐nitrobenzene‐1,2‐dicarboxyl­ato)‐κ8O1,O2:O2,O3;O3,O2:O2,O1‐bis­[triaqua­(2‐carboxy‐3‐nitro­benzoato‐κ2O,O′)lanthanum(III)] dihydrate

The title compound, [La₂(C₈H₃NO₆)₂(C₈H₄NO₆)₂(H₂O)₆]·2H₂O, consists of dimeric units related by an inversion center. The two La^III atoms are linked by two bridging bidentate carboxyl­ate groups and two monodentate carboxyl­ate groups. Each La^III atom is nine‐coordinated by six O atoms from five different carboxyl­ate groups and three from water mol­ecules. Hydrogen bonds between the water mol­ecules and between the solvent water and a carboxyl­ate O atom are observed in the structure. In the crystal packing, there are slipped π–π stacking inter­actions between the parallel benzene rings. Both hydrogen‐bonding and π–π inter­actions combine to stabilize the three‐dimensional supra­molecular network.     

Enantiomerically pure and racemic dimethyl{N‐[(2‐oxidonaphthalen‐1‐yl‐κO)methylidene]valinato‐κ2N,O}tin(IV)

The title compound, [Sn(CH₃)₂(C₁₆H₁₅NO₃)], crystallized from one reaction batch with high enantiomeric excess as both a pure enantiomer and a racemate. The S enantiomer crystallizes in the chiral space group P3₂. The racemate crystallizes in the space group P with R and S enantiomers in the crystal lattice; these form dimers about a crystallographic inversion centre.     

{4‐[(Carbamimidoylhydrazono)methyl‐κ2N1,N4]‐5‐hydroxymethyl‐2‐methylpyridinium‐3‐olate‐κO}(methanol‐κO)copper(II) dinitrate

The title compound, [Cu(C₉H₁₃N₅O₂)(CH₄O)](NO₃)₂, consists of square‐planar cationic complex units where the Cu^II centre is coordinated by an N,N′,O‐tridentate pyridoxal–aminoguanidine Schiff base adduct and a methanol molecule. The tridentate ligand is a zwitterion exhibiting an almost planar conformation. The dihedral angles between the mean planes of the pyridoxal ring and the six‐ and five‐membered chelate rings are all less than 2.0°. The charge on the complex cation is neutralized by two nitrate counter‐ions. Extensive N—H...O and C—H...O hydrogen bonding connects these ionic species and leads to the formation of layers. The pyridoxal hydroxy groups are the only fragments that deviate significantly from the flat layer structure; these groups are involved in O—H...O hydrogen bonding, connecting the layers into a three‐dimensional crystal structure.     

(Z)‐Bis{μ‐[1‐(2‐naphthyl­methyloxy)propan‐2‐iminato‐O,N:N]}bis[bromobis(tetrahydrofuran‐O)magnesium] ditoluene solvate

The title compound, [Mg₂Br₂(C₁₄H₁₄NO)₂(C₄H₈O)₄]·2C₇H₈, has been crystallized as a C₂‐symmetric dimer and the Mg atom has a distorted octahedral geometry. The metal is chelated by the N atom of the ketiminate and the O atom of the ether moiety, giving a rigid structure.     

Dichloro{N‐[3‐(η5‐cyclopentadienyl)propyl]‐4‐toluenesulfonamido‐κ2N,O}titanium(IV)

The title compound, [Ti(C₁₅H₁₇NO₂S)Cl₂], has a Ti atom bound to the N and O atoms of a p‐toluene­sulfon­amide ligand, which is tethered by a three‐carbon chain to a η⁵‐cyclo­penta­dienyl group. The distorted square‐pyramidal geometry is completed by two Cl atoms. The Ti—N bond length of 2.0375 (13) Å is longer than that in related compounds, the N atom having asymmetric trigonal–planar geometry. Conformational strain relief is noted when compared with ethyl‐tethered compounds.     

Modified polyoxometalate: a novel monocapped bi‐supporting and reduced α‐Keggin structure {PMo12O40[Cu(2,2′‐bpy)]}[Cu(2,2′‐bpy)(en)(H2O)]2

A novel modified polyoxometalate, {PMo₁₂O₄₀[Cu(2,2′‐bpy)]}[Cu(2,2′‐bpy)(en)(H₂O)]₂ [2,2′‐bpy is 2,2′‐bipyridyl (C₁₀H₈N₂) and en is ethylenediamine (C₂H₈N₂)], has been synthesized hydrothermally and structurally characterized by elemental analysis, TG, IR, XPS and single‐crystal X‐ray diffraction. The structural analysis reveals that the compound contains the reduced Keggin polyanion [PMo₁₂O₄₀]^6? as the parent unit, which is monocapped by [Cu(2,2′‐bpy)]²⁺ fragments via four bridging O atoms on an {Mo₄O₄} pit and bi‐supported by two [Cu(2,2′‐bpy)(en)(H₂O)]²⁺ coordination cations simultaneously. There exist strong intramolecular π–π stacking between the capping and supporting units, which play a stabilizing role during the crystallization of the compound. Adjacent POM clusters are further aggregated to form a three‐dimensional supramolecular network through noncovalent forces, hydrogen bonding and π–π stacking interactions. In addition, the photocatalytic properties were investigated in detail, and the results indicated that the compound can be used as a photocatalyst towards the decomposition of the organic pollutant methylene blue (MB).     

Ketten aus Ringen: K5{Li[Ge2O7]} — das erste „Litho-Digermanat”︁

Chains consisting of Rings: K₅{Li[Ge₂O₇]} — the First ‘Litho-Digermanate’ By heating of a well-ground mixture of the binary oxides KO_0.55, Li₂O and GeO₂ (K: Li: Ge = 6.1 : 2.2 : 2; Ni-tube; 600°C; 49 d) we obtained for the first time single crystals of K₅{Li[Ge₂O₇]}. This ‘lithodigermanate’ represents a completely new type of structure: monoclinic, space group P2₁/c, a = 624.9(2) pm, b = 1586.6(8) pm; c = 1058.3(6) pm and β = 109.38(4)°; Guinier-Simon data, Z = 4. The structure was solved by four-circle diffractometer data [Siemens AED II, Mo? Kα ; 2872 I_o(hkl); R = 4.5%, R_w = 3.3%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI, are calculated and discussed.     

Diaqua{6,6′‐dimethoxy‐2,2′‐[propane‐1,3‐diylbis(nitrilomethylidyne‐N)]diphenolato‐O,O′}nickel(II)

In the title compound, [Ni(C₁₉H₂₀N₂O₄)(H₂O)₂], the Ni atom has a distorted octahedral coordination geometry in which the tetradentate Schiff base ligand acts as a cis‐N₂O₂ donor defining an equatorial plane, and water mol­ecules occupy the axial positions. The two parts of the mol­ecule are related by a mirror plane that passes through the Ni atom and is perpendicular to the equatorial plane. The angular distortions from normal octahedral geometry are in the range 1–6°, and the equatorial plane, defined by the donor atoms of the Schiff base, is almost square planar. The six‐membered ring comprising the Ni, the imine N and the propyl­ene C atoms adopts a half‐chair conformation. The Ni—O [2.017 (2) Å] and Ni—N [2.071 (2) Å] distances are within the ranges expected for high‐spin octahedral nickel complexes.     

Stable γ-distonic oxonium ions: R\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm O}\limits^ + $\end{document}HCHR′ĊH2CHR″ and their characteristic reaction

The γ-distonic radical ions R$ \mathop {\rm O}\limits^ + $CHR′CH₂?HR″ and their molecular ion counterparts R$ \mathop {\rm O}\limits^{{\rm + } \cdot } $CHR′CH₂CH₂R″ have been studied by isotopic labelling and collision-induced dissociation, applying a potential to the collision cell in order to separate activated from spontaneous decompositions. The stability of CH₃$ \mathop {\rm O}\limits^ + $HCH(CH₃)CH₂?HCH₃, C₂H₅$ \mathop {\rm O}\limits^ + $HCH(CH₃)CH₂?HCH₃, CH₃$ \mathop {\rm O}\limits^ + $HCH(CH₃)CH₂?H₂, CH₃$ \mathop {\rm O}\limits^ + $HCH₂CH₂?HCH₃ and C₂H₅$ \mathop {\rm O}\limits^ + $HCH₂CH₂?HCH₃, has been demonstrated and their characteristic decomposition, alcohol loss, identified. For all these γ-distonic ions, the 1,4-H abstraction leading to their molecular ion counterpart exhibits a primary isotope effect.     

Poly[[triaquazinc(II)]‐μ3‐4‐nitrophthalato‐κ3O1:O2:O2′]

In the title complex, [Zn(C₈H₃NO₆)(H₂O)₃]_n, the two carboxylate groups of the 4‐nitrophthalate dianion ligands have monodentate and 1,3‐bridging modes, and Zn atoms are interconnected by three O atoms from the two carboxylate groups into a zigzag one‐dimensional chain along the b‐axis direction. The Zn atom shows distorted octahedral coordination as it is bonded to three O atoms from carboxylate groups of three 4‐nitrophthalate ligands and to three O atoms of three non‐equivalent coordinated water molecules. The one‐dimensional chains are aggregated into two‐dimensional layers through inter‐chain hydrogen bonding. The whole three‐dimensional structure is further maintained and stabilized by inter‐layer hydrogen bonds.     

Bis{μ‐2‐[(1,5‐diaza‐1‐cyclooctyl)methyl]phenolato‐N,N′,O:O}bis[chlorozinc(II)] diacetone solvate: design of a square‐pyramidal ZnN2O2Cl complex

The title complex, [Zn₂(C₁₃H₁₉N₂O)₂Cl₂]·2C₃H₆O, resides on a crystallographic inversion center. The two Zn^II centers bridged by the phenoxo groups are in pentacoordinated distorted square‐pyramidal coordination environments with an intramolecular Zn?Zn distance of 3.175 (3) Å. The mesocyclic ligand takes a boat–chair conformation and an H atom from the 1,5‐di­aza­cyclo­octane ring effectively blocks the axial coordination site opposite the Cl ligand to form the ZnN₂O₂Cl geometry. The crystal structure is stabilized by a N—H?O hydrogen bond between the amino group and an acetone mol­ecule.