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Carbamazepine (CBZ) and aspirin (ASP) drug molecules in their 1:1 cocrystal interact by relatively strong hydrogen bonds and aromatic–aromatic contacts. The crystal structure and the experimental electron density in the CBZ:ASP cocrystal were derived from a high resolution X-ray diffraction experiment at 100 K, and the results are compared to those previously obtained for the CBZ form III. The isobaric thermal expansion tensor appears to be much more anisotropic for the cocrystal than for CBZ form III. The thermal expansion coefficients αV are found equal to 1.3 for CBZ III and 1.5 × 10–4 K–1 for the CBZ:ASP cocrystal. The interactions in the CBZ:ASP cocrystal have also been analyzed through the electrostatic properties derived from both experimental and theoretical electron densities: topological features, atomic charges, and electrostatic potential. A very good agreement was found for the values of the electron density at the critical points ρ(rCP) obtained from both experiment and theory. This is not, ...

The present work describes the synthesis, structural characterization, Hirshfeld analysis, and antibacterial assays of two hydroxy Schiff bases with triazole moiety: N-[(E)-(3-hydroxy)methylidene]-4H-1-2-4 triazol-4-amine (L1) and N-[(E)-(2,4-dihydroxy)methylidene]-4H-1-2-4 triazol-4-amine (L2). The interaction of these two Schiff bases with AgNO3 leads to Ag(I) dimer [Ag(L1)](NO3) in the case of the first ligand (L1) and polymer [Ag(L2)]n(NO3)n(H2O) for (L2). Crystal structure determination and Hirshfeld analysis reveal the presence of two important hydrogen bond interactions in the four compounds, O…H and H…N, involving nitrogen atoms of triazole ring. Contribution of these two types of hydrogen bonds evolves inversely from (L1) which contains one –OH, to (L2) containing two –OH, then to [Ag(L1)](NO3) dimer and finally to [Ag(L2)]n(NO3)n(H2O) polymer. Indeed, we observed an increase of the percentage to the Hirshfeld surfaces of O…H contribution from (L1) to [Ag(L2)]n(NO3)n(H2O) passing by (L2) and [Ag(L1)](NO3), while the percentage of N…H decrease in the same way. Antibacterial activity of the free ligands (L1), (L2) and their silver complexes [Ag(L1)](NO3) and [Ag(L2)]n(NO3)n(H2O) were evaluated against four Gram-negative (E. coli, Salmonella typhimurium, Klebsiella pneumoniae and Serratia marcescens) and two Gram-positive (Staphylococcus aureus, streptococcus) bacteria strains, using the standard antibiotics, Colistin, Fosfomycin, Gentamycin, Erythromycin, Rifampicin, Amikacin, Ofloxacin and Amoxicillin as positive controls. AgNO3 salt was also used as second control test. The results of this evaluation reveal that, while the two Schiff bases inhibit the growth of the Serratia Marcescens bacterium only, the two Ag(I) complexes are active for all bacteria, with activities comparable to the ones of silver nitrate. However, [Ag(L2)]n(NO3)n(H2O) complex appears significantly more efficient than the AgNO3 salt against Klebsiella Pneumoniae.

We report here a one-step synthesis of the new isoxazolyl-benzimidazolones and isoxazolinyl-benzimidazolones by 1,3-dipolar cycloaddition of the p-substituted benzonitrile oxides and mesitonitrile oxide with 1-cyclohex-1-en-1-yl-3-propargyl-benzimidazolone or 1-cyclohex-1-en-1-yl-3-allyl-benzimidazolone. In all cases these cycloadditions are completely regio- and chemoselective. The structures of new cycloadducts obtained are elucidated by their analytical and spectral data. The relative stereochemistry of the cycloadduct 8 was confirmed by single crystal X-ray analysis.

We report herein the diastereoselective C(sp3)–H arylation of glycosides. A wide range of β- and α-glycosides proved able to selectively undergo Pd(II)-catalyzed coupling with diverse aryl iodides to assemble a large library of functionalized 3-arylglycosylamides. DFT calculations were performed to elucidate the unexpected trans stereoselectivity of this reaction.

The two-dimensional (2-D) catena-{Co(amp)3Cr(ox)3·6H2O}(amp = 2-picolylamine, ox = oxalate) compound is built by the [Co(amp)3]3+ (D) and [Cr(ox)3]3– (A) ions via multiple hydrogen bonds and hosts well-resolved R12 dodecameric discrete water cluster rings between its stacked layers. It undergoes reversible single crystal to single crystal transformation upon dehydration and rehydration in air, both processes being correlated to gradual changes from brown (hydrated phase) to green (dehydrated phase) and vice versa. The water uptake mass of this compound is 0.13 g/g of sample, and the rehydration process needs 90 min. The rate limiting step of the rehydration process is the diffusion of the water molecules into the framework of the dehydrated phase because the latter does not have voids. The 2-D catena-{Co(amp)3Cr(ox)3·6H2O} can undergo many cycles of dehydration/rehydration (breathing) processes without losing its crystallinity. During these processes, its unit cell contracts and expands by 9.39% along the...

Two alkaline earth–tetrazole compounds, namelycatena-poly[[[triaquamagnesium(II)]-μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N5] hemi{bis[μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N2]bis[triaquamagnesium(II)]} monohydrate], {[Mg(C2HN9)(H2O)3][Mg2(C2HN9)2(H2O)6]0.5·H2O}n, (I), and bis[5-(pyrazin-2-yl)tetrazolate] hexaaquamagnesium(II), (C5H3N6)[Mg(H2O)6], (II), have been prepared under hydrothermal conditions. Compound (I) is a mixed dimer–polymer based on magnesium ion centres and can be regarded as the first example of a magnesium–tetrazolate polymer in the crystalline form. The structure shows a complex three-dimensional hydrogen-bonded network that involves magnesium–tetrazolate dimers, solvent water molecules and one-dimensional magnesium–tetrazolate polymeric chains. The intrinsic cohesion in the polymer chains is ensured by N—H...N hydrogen bonds, which formR22(7) rings, thus reinforcing the propagation of the polymer chain along theaaxis. The crystal structure of magnesium tetrazole salt (II) reveals a mixed ribbon of hydrogen-bonded rings, of typesR22(7),R22(9) andR24(10), running along thecaxis, which are linked byR24(16) rings, generating a 4,8-cflunet.

The construction of supramolecular architectures based on inorganic–organic coordination frameworks with weak noncovalent interactions has implications for the rational design of functional materials. A new crystalline binuclear copper(II) one-dimensional polymeric chain, namely catena-poly[[[tetrakis(μ-4-azaniumylbutanoato-κ2 O:O′)dicopper(II)(Cu—Cu)]-μ-chlorido-[diaquadichloridocopper(II)]-μ-chlorido] bis(perchlorate)], {[Cu3Cl4(C4H9NO2)4(H2O)2](ClO4)2} n , was obtained by the reaction of 4-aminobutyric acid (GABA) with CuCl2·2H2O in aqueous solution. The structure was established by single-crystal X-ray diffraction and was also characterized by IR spectroscopy and magnetic measurements. The crystal structure consists of [{Cu2(GABA)4}{CuCl4(H2O)2}]+ cations and isolated perchlorate anions. Two symmetry-related CuII centres are bridged via carboxylate O atoms into a classical paddle-wheel configuration, with a Cu...Cu distance of 2.643 (1) Å, while bridging Cl atoms complete the square-pyramidal geometry of the metal atoms. The Cl atoms connect the paddlewheel moieties to a second CuII atom lying on an octahedral site, resulting in infinite helical chains along the c axis. The packing motif exhibits channels containing free perchlorate anions. The crystal structure is stabilized by hydrogen bonds between the perchlorate anions, the coordinated water molecules and the ammonium groups of the polymeric chains. The magnetic analysis of the title compound indicates a nontrivial antiferromagnetic behaviour arising from alternating weak–strong antiferromagnetic coupling between neighbouring CuII centres.

The unit cell contains eight molecules of the title compound, with half a water molecule per main molecule, C23H20N2·0.5H2O. The seven-membered diazepine ring adopts a twist-boat conformation and makes dihedral angles of 85.08 (7) and 32.79 (7)° with the phenyl and styryl substituents, respectively. In the crystal, the organic molecules are linked by C—H...N hydrogen bonds into chains running along the b-axis direction. The water molecule, located on a twofold rotation axis, forms hydrogen bridges, connecting two adjacent chains.

In the title compound, C22H21N5O, the triazole ring is inclined at 16.88 (12)° to its phenyl substituent and is almost normal to the benzimidazole ring system, making a dihedral angle of 88.40 (8)°. The cyclohexenyl ring adopts a half-chair conformation and its mean plane is inclined to the benzimidazole ring system by 78.75 (12)°. In the crystal, molecules are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional network.

The new hybrid compound (C6H14N2)[Cu(H2O)(6)][Cu(SeO4)(2)(H2O)(4)](2) crystallizes in the monoclinic system, space group P2(1)/n, with the unit cell parameters: a = 7.2469(2) angstrom, b = 9.5360(2) angstrom, c = 22.1919(5) angstrom, and beta = 95.789(2)degrees. The structure was solved by conventional direct methods. The R and wR values for 76142 measured reflections were 0.0337 and 0.0625, respectively. Within the structure of this new compound, the transition metal adopts two types of octahedral coordination. Indeed, Cu1 is coordinated by four water molecules and two selenate groups to form the tetraaquadiselenatocuprate(II) anion [Cu(SeO4)(2)(H2O)(4)](2-), whereas Cu2 adopts another octahedral environment formed by six water molecules, but three of them crystallographically independent. The Cu1 and Cu2 atoms display the socalled (4+1+1) and (4+2) type of coordination, respectively, that has often been observed in other compounds containing the same transition metal, which is consistent with a Jahn-Teller distortion. The crystal structure of the title complex consists of isolated metallic polyhedra and disordered dabcodiium cations linked together by two types of hydrogen bond, OW-H center dot center dot center dot O and N-H center dot center dot center dot O, only. The thermogravimetric analysis shows that the dehydration of the compound takes place in four steps. The decomposition leads to the copper oxide in the last stage.

Accepted 19 Nov 2013; International audience; A mixed-valence salt of tTTF-I with ClO4(-), formulated as (tTTF-I)2ClO4, is characterized by the presence of two crystallographically independent donor molecules, segregated in different layers and linked together through I***O interactions with the ClO4(-) anion disordered at room temperature. The tTTF-I donor molecule was prepared by metallation of tTTF (trimethylene tetrathiafulvalene) followed by reaction with iodine to afford the mono and diiodo derivatives tTTF-I and tTTFI2, respectively. The crystal structure of the latter neutral tTTFI2 shows the occurrence of strong type II, II halogen bond interactions. Band structure calculations of the dual-layer structure of the 2 : 1 salt (tTTF-I)2ClO4 show co-existence of both 1D open and 2D closed Fermi surfaces. The salt undergoes a metal-insulator phase transition at T(MI) = 90 K, associated with an electronic dimensionality decrease, since already at 100 K, the 2D part of the Fermi surface transforms into 1D corrugated planes. High resolution X-ray investigations performed at 100 K, combined with multipolar refinements, indicate an approximately equivalent +0.5e charge in both donor molecules, as also deduced from the intramolecular bond distances. On the other hand, Raman spectroscopic investigations show that at ambient temperature the charge is actually distributed non-uniformly in conducting layers of tTTF-I molecules, with the identification of molecules with charges +1, +0.5, 0e, while at low temperature the charge distribution becomes essentially uniform (+0.5e), as confirmed from the X-ray high resolution data. These apparently contradictory behaviors are actually a consequence of a partial electron transfer between the two independent slabs to reach a common Fermi level in the metallic phase.

Trimers based on intermolecular halogen-bonding interactions (Hal3-synthons) have been studied in hexachlorobenzene, hexabromobenzene, pentachlorophenol, and pentabromophenol. Attention is paid to the comparison of Cl3- and Br3-synthons and to their competition with hydrogen bonds (HBs), based on the experimental and theoretical charge density analyses in crystal and gas phases. The main differences between Cl3- and Br3-synthons are established coming from the particular structure of the valence shell charge concentration region in Cl and Br atoms. Electrophilic–nucleophilic interactions take place within the intermolecular regions of Hal3-synthons by putting face-to-face charge depletion (CD) and charge concentration (CC) regions belonging to the valence shell of the halogen atoms. The electrostatic interaction follows the electrophilic and nucleophilic power of these regions and is monitored by the negative Laplacian values normalized to charge density unit (L/ρ) at the corresponding topological critica...

The coordination structure of M(4)L(4)H(-8) macromolecules (M = Ni(II), Cu(II), Pd(II)) containing small peptidic ligands (L = Xaa-His or Xaa-His-Yaa) has been predicted primarily on the basis of spectroscopic and potentiometric data in the literature. In this work, the neutral tetranuclear nickel(II) complex 1 formed with four double-deprotonated ligands (L = α-methyl-alanyl-histamine) was prepared, and its crystal structure was determined (C(36)H(56)N(16)Ni(4)O(4)·4.5CH(3)OH·1.5H(2)O: a = 11.2645(4) A, b = 23.5003(8) A, c = 20.9007(7) A, β = 102.321(1)°, monoclinic, P2(1)/c, Z = 4). In complex 1, the metal ions have a square planar geometry with 4N donor set consisting of the N-terminal amino nitrogen, the deprotonated amide nitrogen, the imidazole N(3) atom, and the deprotonated imidazole N(1) atom of the adjacent ligand. The latter nitrogen atom provides the connection of the four NiLH(-2) units forming a C(1) symmetrical saddle-like shape. The complexation of L with Ni(II) ion has been studied by a potentiometric method combined with UV-visible spectrophotometric titration. At pH 8.0, the predominant species is M(4)L(4)H(-8) with pK(4)(oligomerization) = 5.73. The tetranuclear structure of complex 1 was also studied in solution by (1)H and (13)C NMR spectroscopy suggesting a structure of symmetry S(4). DFT calculations on optimized structure in symmetry C(1) and S(4) have been performed to explain the observed differences in solution and in solid state. The nuclearity was also confirmed in solution by ESI-HRMS analysis.

Correlative studies of three oxalato-bridged polymers, obtained under hydrothermal conditions for the two isostructural compounds {Rb(HC2O4)(H2C2O4)(H2O)2}∞1, 1, {H3O(HC2O4)(H2C2O4).2H2O}∞1, 2, and by conventional synthetic method for {Rb(HC2O4)}∞3, 3, allowed the identification of H-bond patterns and structural dimensionality. Ferroïc domain structures are confirmed by electric measurements performed on 3. Although 2 resembles one oxalic acid sesquihydrate, its structure determination doesn’t display any kind of disorder and leads to recognition of a supramolecular network identical to hybrid s-block series, where moreover, unusual H3O+ and NH4+ similarity is brought out. Thermal behaviors show that 1D frameworks with extended H-bonds, whether with or without a metal center, have the same stability. Inversely, despite the dimensionalities, the same metallic intermediate and final compounds are obtained for the two Rb+ ferroïc materials.

In the two title compounds, cytosinium hydrogen sulfate, C(4)H(6)N(3)O(+).HSO(4)(-), (I), and cytosinium perchlorate, C(4)H(6)N(3)O(+).ClO(4)(-), (II), the asymmetric units comprise a cytosinium cation with hydrogen sulfate and perchlorate anions, respectively. The crystal structures of (I) and (II) are similar; that of (I) is characterized by a three-dimensional N-H...O, O-H...O and C-H...O hydrogen-bonded network. In (I) and (II), two-dimensional layers are formed by N-H...O and C-H...O hydrogen bonds and, in the case of (I), they are linked by O-H...O hydrogen bonds where the anion acts as a donor and the cation as an acceptor. The hydrogen-bonded sheets in (II) form an angle of 87.1 degrees.

Slightly attractive: The attractive and anisotropic nature of the ClCl interaction in C(6)Cl(6) is experimentally demonstrated from an expansion of the electron density rho(r) around the chlorine nuclei. The interaction is explained in a model in which there is a bonding attraction involving electron-deficient (see picture, blue) and electron-rich (red) regions of adjacent Cl atoms.

International audience; Two new polymorphs of Schiff base, (E)-2-((2,6-dichlorobenzylidene)amino)benzonitrile, were prepared from the condensation of 4-amino-benzonitrile and 2,6-dichlorobenzaldehyde. The two polymorphs crystallize in two different space groups: P21/c for polymorph (I) with volume 1264.23(2) angstrom(3) and Pbca for polymorph (II) with volume 2469.3(2) angstrom(3). The two polymorphs have been characterized by FT-IR and UV-VIS spectroscopy. The crystal structures of both compounds were determined by single X-ray analysis. The difference between the two polymorphs was observed at the angle between the two phenyl rings which is 4.81 degrees for the first one and 82.27 degrees for the second one. Both crystal structures are built on the basis of moderate and weak hydrogen bonds. Theoretical calculations on isolated molecules at the MP2 cc-pVDZ level show that the two polymorphs correspond to two molecular conformations that are within less than 1 kJ mol(-1) and DFT periodic calculations indicate that (II) is more stable than (I) by 4.1 kJ mol(-1) of formula unit. Additionally, we performed TD-DFT calculation for free ligands to support the experimental data.

A new Ce(III)-malonate, growth by hetero-nuclearsynthesis, is investigated structurally at 100K. In this oxobridgedmaterial, the bi-anion does not allow the formation ofany synthons, but various bridges form connections displayingtypical sub-features. Cross-linked edge-shared CeO9 and CeO7(H2O)3 polyhedrons built up 3D packing accommodating twowater molecules embedded in extensive H-bonds. Stable at 25°C, it undergoes concomitant dehydration and decarboxylationsequences. By comparison, Ca(II)-hydrogenmalonate and acidicBa-malonate are also oxo-bridged polymers, but obtained differentlyand are much more stable. The former shows face-sharingbinuclear units, and synthons. The protonated ligands present inthe two alkaline-earth materials give peculiar decompositionprocess.Supporting information: TGA/ DTA/ DTTA curves of Cabasedcompound, TGA/ DTA/ DTTA curves of Ba-based compound,Coordination polyhedrons and fragment of 3D frameworkin Ce-malonate, Cross-linked layers in Ce-malonate, TheC(6) synthons in Ca-based compound, The bi-polyhedron stackingin Ca-based compound, Crystal data, collection proceduresand refinement for Ce-malonate, Selected geometric parametersin Ce coordination spheres, Hydrogen-bond geometry in Cemalonate,XRPD(X-ray powder diffraction) patterns of someintermediate and final TG products.

The crystal structures of four compounds X n[Fe(CN)5NO] with the different inorganic and organic cations X n = Pb, (H3O+CH6N+), (C2N2H7)2 and (C16H36N)2 were determined. (H3O+CH6N+)[Fe(CN)5NO] and (C2N2H7)2[Fe(CN)5NO] crystallize in the non-centrosymmetric space groups Cmc21 and Pca21, respectively. Two metastable states can be excited by irradiation with light in each of these two compounds. Pb[Fe(CN)5NO] and (C16H36N)2[Fe(CN)5NO] crystallize in the centrosymmetric space groups Pnma and P21/n, respectively, but only one metastable state can be obtained at 110 K. In (H3O+CH6N+)[Fe(CN)5NO] and (C2N2H7)2[Fe(CN)5NO] the cations are disordered. The disorder is produced by symmetry related hydrogen bonds. The hydrogen bonds are established for all organic cations, but they are weak in (C16H36N)2[Fe(CN)5NO]. The donor-acceptor relation is fulfilled between the hydrogen atoms of the cations and the nitrogen atoms of the cyanide ligands. The light-induced metastable states, created by irradiation with light in the spectral range Δλ = 410–500 nm at 110 K, were investigated by Differential Scanning Calorimetry. The isothermal measurements show that the decay of the metastable states is purely exponential. From the dynamical measurements of heat flow versus temperature the activations energies and frequency factors of the metastable states are obtained.

International audience; The nature of interactions between face-to-face staggered stacked quinoid rings with pi-systems, observed with a short inter-ring centroid. centroid distance, is analyzed by experimental and theoretical methods. Charge density studies based on X-ray diffraction and DFT calculations, complemented by impedance spectroscopy, were employed to define the electronic and structural characteristics of the quinoid rings responsible for their interactions within the crystal packing. The crystal packing is mainly stabilized by strong electrostatic interactions between the K+ cation and the hydrogen chloranilate anion. The proximity and orientation of the stacked quinoid rings in parallel glide-plane arrangement are partly governed by the non-covalent interactions within the dimer. The estimated contribution of dispersion energy to the stacking of the rings about 10 kcal mol(-1), as calculated by DFT methods, is comparable to medium-strong hydrogen bonding. The electronic structure of 3,6-dichloro-2,5-dihydroxyquinone monoanion exhibits alternating electron-rich and electron-poor regions. The calculated electrostatic energy shows variations with the relative orientation of rings within dimers reaching ca. 10-15 kcal mol(-1). Thus, the nature of interactions between pi-systems of quinoid rings can be described by a polar/pi model where electrostatic complementarity plays a determinant role in pi-stacking orientation. These interactions have great potential in crystal engineering and may be employed in the design of functional materials.

Single crystals of the new compound (H2dabco)[Cu(H2O)6] [Cu(SeO4)2(H2O)4]2 are prepared in good yield (not given) from aqueous solutions of CuCO3·2Cu(OH)2, DABCO, and H2SeO4 in the molar ratio of 1:1:2 at room temperature.

The new generation of X-ray detectors, the hybrid pixel area detectors or `pixel detectors', is based on direct detection and single-photon counting processes. A large linearity range, high dynamic and extremely low noise leading to an unprecedented high signal-to-noise ratio, fast readout time (high frame rates) and an electronic shutter are among their intrinsic characteristics which render them very attractive. First used on synchrotron beamlines, these detectors are also promising in the laboratory, in particular for pump-probe or quasi-static experiments and accurate electron density measurements, as explained in this paper. An original laboratory diffractometer made from a Nonius Mach3 goniometer equipped with an Incoatec Mo microsource and an XPAD pixel area detector has been developed at the CRM2 laboratory. MoKα accurate charge density quality data up to 1.21 Å−1resolution have been collected on a sodium nitroprusside crystal using this home-made diffractometer. Data quality for charge density analysis based on multipolar modelling are discussed in this paper. Deformation electron densities are compared to those already published (based on data collected with CCD APEXII and CAD4 diffractometers).

2,4,6-Tribromo-3,5-difluoro-pyridine 1 was used as the starting material for the synthesis of a variety of multifunctional pyridine derivatives. For example, nucleophilic substitution reactions involving appropriate difunctional nucleophiles gave products resulting from intramolecular cyclisation processes and the organolithium derivative 9, readily prepared from 1, could be trapped by various of electrophilic reagents.

The synthesis and full characterization of [(tmc)MnCl]·X (where tmc is 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane and X is BPh4- or BF4-) are reported. The complex is of type I geometry. The manganese ion is pentacoordinated by the four tertiary nitrogen atoms of the macrocycle and one axial chloride. Variable-temperature magnetic susceptibility data indicate that the oxidation state of the manganese ion is +II with S = 5/2. The EPR spectrum exhibits unusual signals, with the main derivative line at g = 3.7 and transitions at more than 900 mT. The cyclic voltammogram of this derivative consists of two reversible systems at +1.14 and +1.36 V vs SCE related by a chemical equilibrium attributed to an isomerization process.

High-resolution single-crystal X-ray diffraction intensities recorded with a charge-coupled device detector at low temperature (100 K) were used to derive the electron density distribution in three Al2SiO5 polymorphs: andalusite, sillimanite, and kyanite. The 27Al nuclear quadrupole coupling tensors were estimated from both the internal polarization contribution of the Al electron density and that of the lattice with electronic multipoles up to octupoles for oxygen atoms and hexadecapoles for Si and Al. Based on new estimations of the 27Al Sternheimer shielding factor, R and the antishielding factor, γ, a close agreement was achieved between the quadrupole coupling tensors at the various Al-sites derived from the X-ray diffraction data for all three polymorphs of Al2SiO5 with those determined previously from single-crystal 27Al NMR spectra.

The metalation of several free base porphyrins by the bismuth salts Bi(NO3)3 and Bi(SO3CF3)3 in DMF or pyridine is described. The resulting stable Bi(III) porphyrin complexes are characterized by electrochemistry, 1H NMR and UV-vis spectroscopy. The structure of ( OEP ) Bi ( SO 3 CF 3) was also determined by single-crystal X-ray diffraction and shows that ( OEP ) Bi ( SO 3 CF 3) exists as a dimer which is stabilized by electrostatic interactions in which the two [(OEP)Bi]+ cations are linked via oxygen atoms of two symmetrically related [Formula: see text] anions, leading to a heptacoordinated bismuth center. Electrochemical oxidation of ( OEP ) Bi ( SO 3 CF 3) and ( T p TP ) Bi ( SO3CF3 ) shows that only the porphyrin macrocycles are oxidized.

X-ray diffraction data sets collected on both Nonius and Siemens (Bruker) goniometers equipped with charge-coupled device (CCD) area detectors have been tested for the electron-density determination of the aluminosilicate mineral compound α-spodumene LiAl(SiO3)2, aluminium lithium silicon oxide. Data collection strategies, reflection intensity peak integration methods and experimental error estimates are different for the two instruments. Therefore, the consistency and quality of the two types of CCD measurements have been carefully compared to each other and to high-resolution data collected on a conventional CAD-4 point-detector diffractometer. Multipole density model refinements were carried out against the CCD data and the statistical factors analysed in terms of experimental weighting schemes based on the standard uncertainties of the diffraction intensities derived by the Nonius and Siemens software programs. Consistent experimental electron-density features in the Si–O–Si and Si–O–Al bridges were found from both CCD data sets. The net atomic charges obtained from the kappa refinements against each CCD data set are also in good agreement and quite comparable with the results of the conventional CAD-4 experiment.

The title compound, [Ca(C3H3O4)2]n, has a polymeric structure, built up from noncentrosymmetric Ca2O12 face-sharing bipolyhedra, linked through the spacers of the ligands and forming a complex three-dimensional framework containing empty channels parallel to the [001] direction. The calcium ion lies on a 2 axis and is coordinated by eight O atoms from six hydrogen malonate ligands in a distorted bicapped dodeca­hedron. The tridentate ligand displays an η5-chelating coordination mode and forms both μ1,1 and μ1,3 bridges. In the extended network, the protonated O atom is involved in a strong hydrogen bond with a deprotonated O atom, forming an infinite array of the ligands. An M—O—M infinite linkage characteristic of metal–organic frameworks is prevented here by cage assembly around the metal.

The title compound, {[Ho2(C4H2O4)3(H2O)4]·3H2O}n, is an open framework formed of corrugated layers built up from noncentrosymmetric binuclear units extended through μ1,3-bridges to give inorganic chains linked in the [100] direction. Additional connections in the [011] direction, through the ligands as spacers, give a three-dimensional structure exhibiting one-dimensional channels occupied by three solvent water mol­ecules. The two independent water-coordinated HoIII atoms each have a nine-coordination mode via seven O atoms from five carboxyl­ate ligands in a tricapped trigonal prism and a monocapped square prism, respectively. Intra­layer hydrogen bonds involve aqua ligands acting as donors, with carboxyl­ate O atoms as acceptors.