A square‐planar tellurium(II) complex with Te,Te′‐chelating ligands

While exploring the chemistry of tellurium‐containing dichalcogenidoimidodiphosphinate ligands, the first all‐tellurium member of a series of related square‐planar E^II(E′)₄ complexes (E and E′ are group 16 elements), namely bis(P,P,P′,P′‐tetraphenylditelluridoimidodiphosphinato‐κ²Te,Te′)tellurium(II) (systematic name: 2,2,4,4,8,8,10,10‐octaphenyl‐1λ³,5,6λ⁴,7λ³,11‐pentatellura‐3,9‐diaza‐2λ⁵,4λ⁵,8λ⁵,10λ⁵‐tetraphosphaspiro[5.5]undeca‐1,3,7,9‐tetraene), C₄₈H₄₀N₂P₄Te₅, was obtained unexpectedly. The formally Te^II centre is situated on a crystallographic inversion centre and is Te,Te′‐chelated to two anionic [(TePPh₂)₂N]⁻ ligands in an anti conformation. The central Te^II(Te)₄ unit is approximately square planar [Te—Te—Te = 93.51 (3) and 86.49 (3)°], with Te—Te bond lengths of 2.9806 (6) and 2.9978 (9) Å.     

Three isotypic polymeric complexes with rare earth cations,but‐2‐enoate anions and 4,4′‐(ethane‐1,2‐diyl)dipyridine and 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligands

Three isotypic rare earth complexes, catena‐poly[[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐bis(μ‐but‐2‐enoato)‐κ³O,O′:O;κ³O:O,O′‐[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐μ‐4,4′‐(ethane‐1,2‐diyl)dipyridine‐κ²N:N′], [Y₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], the gadolinium(III) analogue, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], and the gadolinium(III) analogue with a 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligand, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₀N₂)(H₂O)₂], are one‐dimensional coordination polymers made up of centrosymmetric dinuclear [M(but‐2‐enoato)₃(H₂O)]₂ units (M = rare earth), further bridged by centrosymmetric 4,4′‐(ethane‐1,2‐diyl)dipyridine or 4,4′‐(ethene‐1,2‐diyl)dipyridine spacers into sets of chains parallel to the [20] direction. There are intra‐chain and inter‐chain hydrogen bonds in the structures, the former providing cohesion of the linear arrays and the latter promoting the formation of broad planes parallel to (010).     

Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)4](I3)2

Tetra(N,N′‐tetramethylurea)‐beryllium‐triiodide, [Be(TMU)₄](I₃)₂ ( 1 ) was prepared from beryllium powder and iodine in N,N′‐tetramethylurea to give orange crystals, which were characterized by X‐ray diffraction and IR spectroscopy. Compound 1 crystallizes monoclinically in the space group C2/c with four formula units per unit cell. Lattice dimensions at 100(2) K: a = 1906.6(1), b = 1185.7(1), c = 1895.0(1) pm, β = 113.60(1) °, R₁ = 0.0291. The structure of 1 consists of distorted tetrahedral cations [Be(TMU)₄]²⁺ with Be–O bond lengths of 162.5(5) and 160.8(5) pm and triiodide ions without site symmetry.     

One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

Structure determination of three furan‐substituted benzimidazoles and calculation of π–π and C—H...π interaction energies

The synthesis and structural characterization of 2‐(furan‐2‐yl)‐1‐(furan‐2‐ylmethyl)‐1H‐benzimidazole [C₁₆H₁₂N₂O₂, (I)], 2‐(furan‐2‐yl)‐1‐(furan‐2‐ylmethyl)‐1H‐benzimidazol‐3‐ium chloride monohydrate [C₁₆H₁₃N₂O₂⁺·Cl⁻·H₂O, (II)] and the hydrobromide salt 5,6‐dimethyl‐2‐(furan‐2‐yl)‐1‐(furan‐2‐ylmethyl)‐1H‐benzimidazol‐3‐ium bromide [C₁₈H₁₇N₂O₂⁺·Br⁻, (III)] are described. Benzimidazole (I) displays two sets of aromatic interactions, each of which involves pairs of molecules in a head‐to‐tail arrangement. The first, denoted set (Ia), exhibits both intermolecular C—H...π interactions between the 2‐(furan‐2‐yl) (abbreviated as Fn) and 1‐(furan‐2‐ylmethyl) (abbreviated as MeFn) substituents, and π–π interactions involving the Fn substituents between inversion‐center‐related molecules. The second, denoted set (Ib), involves π–π interactions involving both the benzene ring (Bz) and the imidazole ring (Im) of benzimidazole. Hydrated salt (II) exhibits N—H...OH₂...Cl hydrogen bonding that results in chains of molecules parallel to the a axis. There is also a head‐to‐head aromatic stacking of the protonated benzimidazole cations in which the Bz and Im rings of one molecule interact with the Im and Fn rings of adjacent molecules in the chain. Salt (III) displays N—H...Br hydrogen bonding and π–π interactions involving inversion‐center‐related benzimidazole rings in a head‐to‐tail arrangement. In all of the π–π interactions observed, the interacting moieties are shifted with respect to each other along the major molecular axis. Basis set superposition energy‐corrected (counterpoise method) interaction energies were calculated for each interaction [DFT, M06‐2X/6‐31+G(d)] employing atomic coordinates obtained in the crystallographic analyses for heavy atoms and optimized H‐atom coordinates. The calculated interaction energies are −43.0, −39.8, −48.5, and −55.0 kJ mol⁻¹ for (Ia), (Ib), (II), and (III), respectively. For (Ia), the analysis was used to partition the interaction energies into the C—H...π and π–π components, which are 9.4 and 24.1 kJ mol⁻¹, respectively. Energy‐minimized structures were used to determine the optimal interplanar spacing, the slip distance along the major molecular axis, and the slip distance along the minor molecular axis for 2‐(furan‐2‐yl)‐1H‐benzimidazole.     

Poly­[disilver(I)‐μ8‐1,5‐naphthalene­disulfonato]

The title complex, poly­[disilver(I)‐μ₈‐1,5‐naphthalene­di­sulfon­ato‐3,4‐η:7,8‐η:κ⁶O:O′:O′′:O′′′:O′′′′:O′′′′′], [Ag₂(C₁₀H₆O₆S₂)]_n, exists as a three‐dimensional framework of Ag^I atoms connected by η¹⁰,μ₈‐1,5‐naphthalene­di­sulfonate ligands through both Ag–sulfonate and Ag–η²‐arene interactions. Each Ag^I atom exhibits a distorted tetrahedral geometry defined by three O atoms of independent sulfonate groups and one C=C bond of the naphthalene group.     

Dinuclear Complexes of Copper(I) with Crown Ether‐containing N‐Thiophosphorylated Bis‐thioureas and 2,2′‐Bipyridine or 1,10‐Phenanthroline: Synthesis,Characterization, and Picrate Extraction Properties

Reaction of O,O′‐diisopropylthiophosphoric acid isothiocyanate (iPrO)₂P(S)NCS with 1,10‐diaza‐18‐crown‐6, 1,7‐diaza‐18‐crown‐6, or 1,7‐diaza‐15‐crown‐5 leads to the N‐thiophosphorylated bis‐thioureas N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6 ( H₂L^I ), N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,7‐diaza‐18‐crown‐6 ( H₂L^II ) and N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,7‐diaza‐15‐crown‐5 ( H₂L^III ). Reaction of the potassium salts of H₂L^I–III with a mixture of CuI and 2,2′‐bipyridine ( bpy ) or 1,10‐phenanthroline ( phen ) in aqueous EtOH/CH₂Cl₂ leads to the dinuclear complexes [Cu₂(bpy)₂L^I–III] and [Cu₂(phen)₂L^I–III] . The structures of these compounds were investigated by ¹H, ³¹P{¹H} NMR spectroscopy, and elemental analysis. The crystal structures of H₂L^I and [Cu₂(phen)₂L^I] were determined by single‐crystal X‐ray diffraction. Extraction capacities of the obtained compounds in comparison to the related compounds 1,10‐diaza‐18‐crown‐6, N,N′‐bis[C(=CMe₂)CH₂P(O)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6, N,N′‐bis[C(S)NHP(O)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6 towards the picrate salts LiPic, NaPic, KPic. and NH₄Pic were also studied.     

Chemical Bonding and Pressure‐Induced Change of the Electron Configuration of Ytterbium in β‐YbAgGa2

Single‐phase polycrystalline samples of the intermetallic compound β‐YbAgGa₂ were synthesized by inductive heating and subsequent annealing for eight weeks at 670 K. Magnetic properties were characterized by susceptibility measurements and indicated intermediate valence of ytterbium at ambient pressure. Angle‐dispersive X‐ray powder diffraction data of orthorhombic β‐YbAgGa₂ indicate stability of the phase in the investigated pressure range from 0.1 MPa (ambient pressure) to 19 GPa. The pressure‐induced volume decrease is accompanied by an increase of the effective valence from 2.17 at ambient conditions to 2.71 at 16 GPa as evaluated by X‐ray absorption spectroscopy at the Yb L_III threshold. Analysis of the chemical bonding in β‐YbAgGa₂ by integrating the electron density of the polyanion in basins as defined by the electron localization function results in an electron count Yb^2.7+[(Ag^0.2—)(Ga1(3b)^1.0—)(Ga2(4b)^1.5—)]. This finding is close to the expected values calculated by means of the Zintl rules and fits well the results of magnetic susceptibility measurements and XAS investigations.     

Cobalt(II) chloride complexes with 1,1′‐dimethyl‐4,4′‐bipyrazole featuring first‐ and second‐sphere coordination of the ligand

In catena‐poly[[dichloridocobalt(II)]‐μ‐(1,1′‐dimethyl‐4,4′‐bipyrazole‐κ²N²:N^2′)], [CoCl₂(C₈H₁₀N₄)]_n, (1), two independent bipyrazole ligands (Me₂bpz) are situated across centres of inversion and in tetraaquabis(1,1′‐dimethyl‐4,4′‐bipyrazole‐κN²)cobalt(II) dichloride–1,1′‐dimethyl‐4,4′‐bipyrazole–water (1/2/2), [Co(C₈H₁₀N₄)₂(H₂O)₄]Cl₂·2C₈H₁₀N₄·2H₂O, (2), the Co²⁺ cation lies on an inversion centre and two noncoordinated Me₂bpz molecules are also situated across centres of inversion. The compounds are the first complexes involving N,N′‐disubstituted 4,4′‐bipyrazole tectons. They reveal a relatively poor coordination ability of the ligand, resulting in a Co–pyrazole coordination ratio of only 1:2. Compound (1) adopts a zigzag chain structure with bitopic Me₂bpz links between tetrahedral Co^II ions. Interchain interactions occur by means of very weak C—H...Cl hydrogen bonding. Complex (2) comprises discrete octahedral trans‐[Co(Me₂bpz)₂(H₂O)₄]²⁺ cations formed by monodentate Me₂bpz ligands. Two equivalents of additional noncoordinated Me₂bpz tectons are important as `second‐sphere ligands' connecting the cations by means of relatively strong O—H...N hydrogen bonding with generation of doubly interpenetrated pcu (α‐Po) frameworks. Noncoordinated chloride anions and solvent water molecules afford hydrogen‐bonded [(Cl⁻)₂(H₂O)₂] rhombs, which establish topological links between the above frameworks, producing a rare eight‐coordinated uninodal net of {4²⁴.5.6³} ( ilc ) topology.     

Preparation and Crystal Structures of the Hydrous Mercury Tellurates,HgII(H4TeVIO6) and HgI2(H4TeVIO6)(H6TeVIO6)·2H2O

Single crystals of Hg^II(H₄Te^VIO₆) (colourless to light‐yellow, rectangular plates) and Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O (colourless, irregular) were grown from concentrated solutions of orthotelluric acid, H₆TeO₆, and respective solutions of Hg(NO₃)₂ and Hg₂(NO₃)₂. The crystal structures were solved and refined from single crystal diffractometer data sets (Hg^II(H₄Te^VIO₆): space group Pna2₁, Z = 4, a =10.5491(17), b = 6.0706(9), c = 8.0654(13)Å, 1430 structure factors, 87 parameters, R[F² > 2σ(F²)] = 0.0180; Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O: space group P1¯, Z = 1, a = 5.7522(6), b = 6.8941(10), c = 8.5785(10)Å, α = 90.394(8), β = 103.532(11), γ = 93.289(8)°, 2875 structure factors, 108 parameters, R[F² > 2σ(F²)] = 0.0184). The structure of Hg^II(H₄Te^VIO₆) is composed of ribbons parallel to the b axis which are built of [H₄TeO₆]^2— anions and Hg²⁺ cations held together by two short Hg—O bonds with a mean distance of 2.037Å. Interpolyhedral hydrogen bonding between neighbouring [H₄TeO₆]^2— groups, as well as longer Hg—O bonds between Hg atoms of one ribbon to O atoms of adjacent ribbons lead, to an additional stabilization of the framework structure. Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O is characterized by a distorted hexagonal array made up of [H₄TeO₆]^2— and [H₆TeO₆] octahedra which spread parallel to the bc plane. Interpolyhedral hydrogen bonding between both building units stabilizes this arrangement. Adjacent planes are stacked along the a axis and are connected by Hg₂²⁺ dumbbells (d(Hg—Hg) = 2.5043(4)Å) situated in‐between the planes. Additional stabilization of the three‐dimensional network is provided by extensive hydrogen bonding between interstitial water molecules and O and OH‐groups of the [H₄TeO₆]^2— and [H₆TeO₆] octahedra. Upon heating Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O decomposes into TeO₂ under formation of the intermediate phases Hg^II₃Te^VIO₆ and the mixed‐valent Hg^IITe^IV/VI₂O₆.     

Synthesis and Crystal Structures of O‐2′,3′‐Cyclic Cyclopentanone and Cyclohexanone Ketals of the Cytostatic 5‐Fluorouridine

The synthesis of two O‐2′,3′‐cyclic ketals, i.e., 5 and 6 , of the cytostatic 5‐fluorouridine ( 2 ), carrying a cyclopentane and/or a cyclohexane ring, respectively, is described. The novel compounds were characterized by ¹H‐, ¹⁹F‐, and ¹³C‐NMR, and UV spectroscopy, as well as by elemental analyses. Their crystal structures were determined by X‐ray analysis. Both compounds 5 and 6 show an anti‐conformation at the N‐glycosidic bond which is biased from +ac to +ap compared to the parent nucleoside 2 . The sugar puckering is changed from ^2′E to _3′E going along with a reduction of the puckering amplitude τ_m by ca. 10–13° due to the ketalization. The conformation about the sugar exocyclic bond C(4′)? C(5′) of 5 and 6 remains unchanged, i.e., g⁺, compared with compound 2 .     

Energetic propane‐1,3‐diaminium and butane‐1,4‐diaminium salts of N,N′‐dinitroethylenediazanide: syntheses,crystal structures and thermal properties

The acidity of the amine H atoms and the consequent salt formation ability of ethylenedinitramine (EDNA) were analyzed in an attempt to improve the thermal stability of EDNA. Two short‐chain alkanediamine bases, namely propane‐1,3‐diamine and butane‐1,4‐diamine, were chosen for this purpose. The resulting salts, namely propane‐1,3‐diaminium N,N′‐dinitroethylenediazanide, C₃H₁₂N₂²⁺·C₂H₄N₄O₄^2?, and butane‐1,4‐diaminium N,N′‐dinitroethylenediazanide, C₄H₁₄N₂²⁺·C₂H₄N₄O₄^2?, crystallize in the orthorhombic space group Pbca and the monoclinic space group P2₁/n, respectively. The resulting salts display extensive hydrogen‐bonding networks because of the presence of ammonium and diazenide ions in the crystal lattice. This results in an enhanced thermal stability and raises the thermal decomposition temperatures to 202 and 221 °C compared to 180 °C for EDNA. The extensive hydrogen bonding present also plays a crucial role in lowering the sensitivity to impact of these energetic salts.     

Substituent effects in trans‐p,p′‐disubstituted azobenzenes: X‐ray structures at 100 K and DFT‐calculated structures

The crystal and molecular structures of two para‐substituted azobenzenes with π‐electron‐donating –NEt₂ and π‐electron‐withdrawing –COOEt groups are reported, along with the effects of the substituents on the aromaticity of the benzene ring. The deformation of the aromatic ring around the –NEt₂ group in N,N,N′,N′‐tetraethyl‐4,4′‐(diazenediyl)dianiline, C₂₀H₂₈N₄, (I), may be caused by steric hindrance and the π‐electron‐donating effects of the amine group. In this structure, one of the amine N atoms demonstrates clear sp²‐hybridization and the other is slightly shifted from the plane of the surrounding atoms. The molecule of the second azobenzene, diethyl 4,4′‐(diazenediyl)dibenzoate, C₁₈H₁₈N₂O₄, (II), lies on a crystallographic inversion centre. Its geometry is normal and comparable with homologous compounds. Density functional theory (DFT) calculations were performed to analyse the changes in the geometry of the studied compounds in the crystalline state and for the isolated molecules. The most significant changes are observed in the values of the N=N—C—C torsion angles, which for the isolated molecules are close to 0.0°. The HOMA (harmonic oscillator model of aromaticity) index, calculated for the benzene ring, demonstrates a slight decrease of the aromaticity in (I) and no substantial changes in (II).     

Building Functionality into 4′‐Hydrazone Derivatives of 2,2′: 6′,2″‐Terpyridine

The syntheses of the five 2,2′: 6′,2″‐terpyridine (tpy) ligands 5 – 9 functionalized in the 4′‐position with a hydrazone substituent RR′C?N? NH (R=R′=Me; R=H, R′=4‐BrC₆H₄, 4‐O₂NC₆H₄, 4‐MeOC₆H₄, or 3,5‐(MeO)₂C₆H₃) are described. Protonation of the tpy domain of the ligands is facile. Solution behaviour has been studied by NMR and electronic spectroscopies. Representative structural data are presented for neutral and monoprotonated ligands, and illustrate that H‐bonding involving the formal amine NH unit is a dominant structural motif in all cases.     

Acyclic Schiff base salts derived from 1,3‐diaminopropane and 1,3‐diamino‐2‐hydroxypropane

Two salts of acyclic Schiff base cationic ligands, namely N,N′‐bis(2‐nitrobenzyl)propane‐1,3‐diammonium dichloride monohydrate, C₁₇H₂₂N₄O₄²⁺·2Cl⁻·H₂O, (I), and 2‐hydroxy‐N,N′‐bis(2‐nitrobenzyl)propane‐1,3‐diammonium dichloride, C₁₇H₂₂N₄O₅²⁺·2Cl⁻, (II), were synthesized as precursors in order to obtain new acyclic and macrocyclic multidentate ligands and complexes. The cation conformations in compounds (I) and (II) are different in the solid state, although the cations are closely related chemically. Similarly, the hydrogen‐bonding networks involving ammonium cations, hydroxyl groups and chloride anions are also different. In the cation of compound (II), the hydroxyl group is disordered over two sets of sites, with occupancies of 0.785 (8) and 0.215 (8).     

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 two‐dimensional CdII coordination polymer with 2,2′‐(disulfanediyl)dibenzoate and 1,10‐phenanthroline ligands

In poly[[μ₃‐2,2′‐(disulfanediyl)dibenzoato‐κ⁵O:O,O′:O′′,O′′′](1,10‐phenanthroline‐κ²N,N′)cadmium(II)], [Cd(C₁₄H₈O₄S₂)(C₁₂H₈N₂)]_n, the asymmetric unit contains one Cd^II cation, one 2,2′‐(disulfanediyl)dibenzoate anion (denoted dtdb²⁻) and one 1,10‐phenanthroline ligand (denoted phen). Each Cd^II centre is seven‐coordinated by five O atoms of bridging/chelating carboxylate groups from three dtdb²⁻ ligands and by two N atoms from one phen ligand, forming a distorted pentagonal–bipyramidal geometry. The Cd^II cations are bridged by dtdb²⁻ anions to give a two‐dimensional (4,4) layer. The layers are stacked to generate a three‐dimensional supramolecular architecture via a combination of aromatic C—H...π and π–π interactions. The thermogravimetric and luminescence properties of this compound were also investigated.     

A new ZnII coordination polymer based on 4‐(pyridin‐4‐yl)benzoic and formic acids: in‐situ synthesis,crystal structure and luminescence properties

The title compound, poly[(μ₂‐formato‐κ³O,O′:O)[μ₂‐4‐(pyridin‐4‐yl)benzoato‐κ³N:O,O′]zinc(II)], [Zn(C₁₂H₈NO₂)(HCOO)]_n, has been synthesized in situ and characterized by thermogravimetric analysis (TGA) and single‐crystal and powder X‐ray diffraction analyses. The polymer contains two independent structural units in the asymmetric unit. These are constructed from Zn²⁺ ions, 4‐(pyridin‐4‐yl)benzoate (4‐pbc) bridges and in‐situ‐generated formate ligands, forming two similar two‐dimensional (2D) layer structures. These similar 2D layers are arranged alternately and are linked with each other by dense C—H…O hydrogen bonds to generate a three‐dimensional (3D) supramolecular framework. The crystal is pseudomerohedrally twinned about [201]. Compared with free 4‐Hpbc, the polymer exhibits a red shift and significantly enhanced solid‐state luminescence properties.     

Neue Halogenochalkogen(IV)‐Säuren: [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10]

Novel Halogenochalcogeno(IV) Acids: [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] Systematic studies on halogenochalcogeno(IV) acids containing tellurium and bromine led to the new crystalline phases [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] ( 1 ) and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] ( 2 ). The [Te₂Br₁₀]^2‐ anions consists of two edge‐sharing distorted TeBr₆ octahedra, the oxonium cations are stabilized by crownether. ( 1 ) crystallizes in the monoclinic space group P2₁/n with a = 14.520(5) Å, b = 22.259(6) Å, c = 16.053(5) Å, β = 97.76(3)° and Z = 4, whereas ( 2 ) crystallizes in the triclinic space group with a = 11.005(4) Å, b = 12.103(5) Å, c = 14.951(6) Å, α = 71.61(3)°, β = 69.17(3)°, γ = 68.40(3)° and Z = 1.     

Two polymorphs,with Z′ = 1 and 2, of 2‐amino‐4‐chloro‐6‐morpholino­pyrimidine in P21/c,and 2‐amino‐4‐chloro‐6‐piperidino­pyrimidine,which is isomorphous and almost isostructural with the Z′ = 2 polymorph

Crystallization of 2‐amino‐4‐chloro‐6‐morpholino­pyrimidine, C₈H₁₁ClN₄O, (I), yields two polymorphs, both with space group P2₁/c, having Z′ = 1 (from diethyl ether solution) and Z′ = 2 (from di­chloro­methane solution), denoted (Ia) and (Ib), respectively. In polymorph (Ia), the mol­ecules are linked by an N—H⋯O and an N—H⋯N hydrogen bond into sheets built from alternating R(8) and R(40) rings. In polymorph (Ib), one mol­ecule acts as a triple acceptor of hydrogen bonds and the other acts as a single acceptor; one N—H⋯O and three N—H⋯N hydrogen bonds link the mol­ecules in a complex chain containing two types of R(8) and one type of R(18) ring. 2‐Amino‐4‐chloro‐6‐piperidino­pyrimidine, C₉H₁₃ClN₄, (II), which is isomorphous with polymorph (Ib), also has Z′ = 2 in P2₁/c, and the mol­ecules are linked by three N—­H⋯N hydrogen bonds into a centrosymmetric four‐mol­ecule aggregate containing three R(8) rings.