ALBERT

Beschreibung: The novel hemilabile ferrocenylbisphosphane 1,1′-bis(bis{2-[(dimethylamino)methyl]phenyl}phosphanyl)ferrocene, [Fe{C5H4P(C6H4CH2NMe2-o)2}2] (1), was synthesized by reacting bis(dichlorophosphanyl)ferrocene, [Fe{C5H4(PCl2)}2] with LiC6H4CH2NMe2-o. Treatment of 1 with gray selenium and anhydrous ZnCl2 yielded, respectively, the bisselenide (ferrocene-1,1′-diyl)bis(bis{2-[(dimethylamino)methyl]phenyl}phosphine selenide), [Fe(C23H28N2PSe)2] (2), and the dizinc complex [μ-1,1′-bis(bis{2-[(dimethylamino)methyl]phenyl}phosphanyl)ferrocene-κ2 N,P:κ2 N′,P′]bis[dichloridozinc(II)] dichloromethane monosolvate, [FeZn2Cl4(C23H28N2P)2]·CH2Cl2 (3), and both have been structurally characterized. Both compounds crystallized with the asymmetric unit containing half a molecule and with the Fe atom on an inversion centre. A Hirshfeld surface analysis indicated that the most significant contributions to the crystal packing of 2 are from H...H (76.7%), C...H/H...C (13.2%) and Se...H/H...Se (7.1%) contacts, while those for 3 are from H...H (62.3%), Cl...H/H...Cl (24.4%) and C...H/H...C (10.9%) contacts.

Beschreibung: The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.

Beschreibung: A novel three-dimensional (3D) CdII coordination polymer, namely, poly[[μ2-4,4′-bis(2-methylimidazol-1-yl)-[1,1′-biphenyl]](μ2-5-methylisophthalato)cadmium(II)], [Cd(C9H6O4)(C20H18N4)] n or [Cd(MIP)(4,4′-BMIBP)] n , (I), was synthesized by the hydrothermal method using 5-methylisophthalic acid (H2MIP), 4,4′-bis(2-methylimidazol-1-yl)-[1,1′-biphenyl] (4,4′-BMIBP) and Cd(NO3)2·6H2O, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. Compound (I) exhibits a novel fivefold interpenetrating 3D diamondoid framework. Additionally, it shows fluorescence emission in the solid state and promising photocatalytic activities for the degradation of methylene blue (MB) in water at room temperature.

Beschreibung: The self-assembly reaction of (+)-dibenzoyltartaric acid (D-H2DBTA) with 2,2′-bipyridine (bpy) and Mn(CH3CO2)2·4H2O yielded a new coordination polymer, namely, catena-poly[[[diaqua(2,2′-bipyridine-κ2 N,N′)manganese(II)]-μ-2,3-bis(benzoyloxy)butanedioato-κ2 O 2:O 3] dihydrate], {[Mn(C18H12O8)(C10H8N2)(H2O)2]·2H2O} n or {[Mn(DBTA)(bpy)(H2O)2]·2H2O} n , (I). Complex (I) has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA) and single-crystal and powder X-ray diffraction. It crystallizes in the orthorhombic space group P212121. In the complex, the Mn2+ cation displays a distorted octahedral {MnO4N2} geometry, formed from two carboxylate O atoms of two DBTA2− ligands, two cis-oriented N atoms from one chelating 2,2′-bipyridine ligand and two trans-oriented O atoms from coordinated water molecules. The polymer displays a 1D chain with an Mn...Mn distance of 9.428 (1) Å. Due to the presence of flexible polycarboxylate and rigid bipyridyl ligands in the molecular structure, a high thermal stability of the complex is attained. The magnetic properties of (I) were analyzed based on the mononuclear Mn2+ model due to the long intramolecular Mn...Mn distance. The zero field splitting (ZFS) contribution in the high-spin Mn2+ cation is almost negligible and there are weak antiferromagnetic couplings between 1D chains [zJ′ = −0.062 (5) cm−1], corresponding to an intermolecular Mn...Mn distance of 7.860 (2) Å.

Beschreibung: The structure determinations of phases (II) and (III) of barium dicalcium hexakis(propanoate) {or poly[hexa-μ4-propanoato-bariumdicalcium], [BaCa2(C3H5O2)6] n } are reported at 240 and 130 K, respectively [phase (I) was determined previously by Stadnicka & Glazer (1980). Acta Cryst. B36, 2977–2985; our structure determination of phase (I) at room temperature is included in the supporting information]. In the high-temperature phase, the Ba2+ cation is surrounded by six carboxylate groups in bidentate bridging modes. In the low-temperature phases, five carboxylate groups act in bidentate bridging modes and one acts in a monodentate bridging mode around Ba2+. The Ca2+ cations are surrounded by six carboxylate O atoms in a trigonal antiprism in all the structures. The Ba2+ and Ca2+ cations are underbonded and significantly overbonded, respectively, in all the phases. The bonding of the Ba2+ cation increases slightly at the cost of the bonding of Ca2+ cations during cooling to the low-temperature phases. The phase transitions during cooling are accompanied by ordering of the ethyl chains. In room-temperature phase (I), all six ethyl chains are positionally disordered over two positions in the crossed mode, with additional splitting of the ethyl α- and β-C atoms. In phase (II), on the other hand, there are three disordered ethyl chains, one with positionally disordered ethyl α- and β-C atoms, and the other two with positionally disordered ethyl β-C atoms only, and in the lowest-temperature phase (III) there are four ordered ethyl chains and two disordered ethyl chains with positionally disordered ethyl β-C atoms only.

Beschreibung: The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. A new twofold interpenetrated three-dimensional (3D) MOF, namely, poly[[triaqua(μ4-(2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionato-κ7 O 1:O 1,O 1′:O 4:O 4,O 4′,O 4′′)(μ3-(2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionato-κ3 O 1:O 4:O 4)dicadmium(II)] dihydrate], {[Cd2(C14H14N2O6)2(H2O)3]·2H2O} n , (I), has been synthesized by the reaction of Cd(CH3COO)2·2H2O with the synthesized ligand (2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionic acid (H2 L). Single-crystal X-ray diffraction analysis reveals that the carboxylate groups from two crystallographically independent L 2− dianions link the cadmium cations into a one-dimensional helical secondary building unit (SBU). The resulting SBUs are extended into a 3D metal–organic framework via the terephthalamide moiety of the ligand as a spacer. In the crystal, two independent MOFs interpenetrate each other, thus producing a twofold interpenetrated 3D architecture, which shows an unprecedented 2-nodal (7,9)-connected net with the point (Schläfli) symbol (37·46·58)(38·411·516·6). MOF (I) was further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. The photoluminescence properties and UV–Vis absorption spectrum of (I) have also been investigated. The MOF exhibits enhanced fluorescence emission with a high photoluminescence quantum yield of 31.55% and a longer lifetime compared with free H2 L.

Beschreibung: Four new solvates of the anti-HIV compound etravirine [systematic name: 4-({6-amino-5-bromo-2-[(4-cyanophenyl)amino]pyrimidin-4-yl}oxy)-3,5-dimethylbenzonitrile, C20H15BrN6O] with dimethyl sulfoxide (C2H6OS, two distinct monosolvates), 1,4-dioxane (C4H8O2, the 0.75-solvate) and N,N-dimethylacetamide (C4H9NO, the monosolvate), which exhibit conversion to the same anhydrous etravirine phase upon desolvation, and a stable etravirinium oxalate salt {6-amino-5-bromo-4-(4-cyano-2,6-dimethylphenoxy)-2-[(4-cyanophenyl)amino]pyrimidin-1-ium hemioxalate, C20H16BrN6O+·0.5C2O4 2−} were obtained. The crystal structures were solved by single-crystal X-ray diffraction and analyzed by powder X-ray diffraction, and the intermolecular interactions were explored by Hirshfeld surface analysis. Lattice energies were evaluated using the atom–atom force field Coulomb–London–Pauli (AA CLP) approximation, which distributes the total energy as four separate contributions: Coulombic, polarization, dispersion and repulsion. The formation of the solvates and the oxalate salt was further characterized by thermal analysis and IR spectroscopy.

Beschreibung: A new two-dimensional (2D) coordination polymer, namely, poly[[diaqua-[μ4-2,2′-[terephthaloylbis(azanediyl)]diacetato]calcium(II)] monohydrate], {[Ca(C12H10N2O6)(H2O)2]·H2O} n , (I), has been synthesized by the reaction of CaCl2 with 2,2′-[terephthaloylbis(azanediyl)]diacetic acid (H2 L). The title compound was structurally characterized by single-crystal X-ray diffraction analysis, elemental analysis and IR spectroscopy. In the crystal structure of (I), each CaII cation binds to six carboxylate groups from four symmetry-related L 2− dianions. The hexadentate L 2− ligand links four symmetry-related calcium cations into a 2D layer-like structure, which can be simplified as a uninodal SP 2-periodic (3,6)III net with the point symbol (43·63). In the lattice, all layers pack in parallel arrays through weak interlayer hydrogen bonding and π–π interactions. The thermal stability and photoluminescence properties of (I) have been investigated. Thermogravimetric analysis reveals the different thermal stabilities of the two coordinated water molecules due to their different hydrogen-bonding interactions. The title coordination polymer exhibits an excitation-wavelength-dependent fluorescence in the solid state.

Beschreibung: The synthesis, crystal structure and spectroscopic and electronic properties of N-(2-methyl-5-nitrophenyl)-4-(pyridin-2-yl)pyrimidin-2-amine (NPPA), C16H13N5O2, a potential template for drug design against chronic myelogenous leukemia (CML), is reported. The design and construction of the target molecule were carried out starting from the guanidinium nitrate salt (previously synthesized) and the corresponding enaminone. X-ray diffraction analysis and a study of the Hirshfeld surfaces revealed important interactions between the nitro-group O atoms and the H atoms of the pyridine and pyrimidine rings. A crystalline ordering in layers, by the stacking of rings through interactions of the π–π type, was observed and confirmed by a study of the shape-index surfaces and dispersion energy calculations. Quantitative electrostatic potential studies revealed the most positive value of the molecule on regions close to the N—H groups (34.8 kcal mol−1); nevertheless, steric impediments and the planarity of the molecule do not allow the formation of hydrogen bonds from this group. This interaction is however activated when the molecule takes on a new extended conformation in the active pocket of the enzyme kinase (PDB ID 2hyy), interacting with protein residues that are fundamental in the inhibition process of CML. The most negative values of the molecule are seen in regions close to the nitro group (−35.4 and −34.0 kcal mol−1). A molecular docking study revealed an energy affinity of ΔG = −10.3 kcal mol−1 for NPPA which, despite not having a more negative value than the control molecule (Imatinib; ΔG = −12.8 kcal mol−1), shows great potential to be used as a template for new drugs against CML.

Beschreibung: The present report lists selected publications on centrosymmetric compounds that manifest second harmonic generation responses in a laser, along with a few publications that dispute the laser outcomes. Two studies provide a plausible explanation for this apparent contradiction between second-order nonlinear susceptibility and inversion symmetry: the crystals are noncentrosymmetric and are twinned by inversion. If crystal structures of SHG-active compounds are presented in centrosymmetric settings, the authors of the publications may consider stipulating that the true space group is likely to be one of the noncentrosymmetric sub-space groups.