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Reaction between Mn(NO3)2 ⋅ 6H2O, Zn(NO3)2 ⋅ 6H2O, 1,3,5‐tri(2‐hydroxyethyl)‐1,3,5‐triazacyclohexane (H3L) and pyrazole in MeOH under basic conditions leads to the formation of the decanuclear complex [MnIII6MnII2ZnII2(L)2(pyr)4O4(OH)4(NO3)2 (MeOH)2(H2O)4](NO3)2 ⋅ Η2Ο (1 ⋅ Η2Ο). The metallic core of the cationic cluster consists of a central hexagonal‐bipyramidal {MnIII4MnII2ZnII2} unit connected to two peripheral trivalent Mn centers arranged in a "trans" fashion, with one MnIII center lying above and one MnIII center below the hexagonal plane. Replacing Mn(NO3)2 ⋅ 6H2O with MnBr2 ⋅ 4H2O and repeating the same reaction leads to the formation of the related, neutral decanuclear complex [MnIII6MnII2ZnII2(L)2(pyr)4O4(OH)4Br4(H2O)2] (2), displaying the same metallic core as 1. Addition of THF to the reaction mixture that produces (2) affords the neutral dodecanuclear complex [MnIII6MnII2ZnII4(L)2(pyr)6O4(OH)4Br6(H2O)4] ⋅ 8THF (3 ⋅ 8THF), whose metallic skeleton retains the central hexagonal‐bipyramidal {MnIII4MnII2ZnII2} unit found in 1 and 2 but is now connected to two peripheral {MnIIIZnII} units. Magnetic susceptibility and magnetization measurements carried out in the T=2–300 K temperature range and in fields up to B=7.0 T for all three complexes reveal dominant antiferromagnetic exchange interactions. [ABSTRACT FROM AUTHOR]

Reaction of Co(OAc)2·4H2O and Hsal in a basic MeCN solution affords the hexadecanuclear wheel [Co16(sal)16(OAc)16]·16MeCN (1·16MeCN) that displays ferromagnetic nearest neighbour exchange and has pseudo-calixarene character. Symmetry equivalent wheels self-assemble to form remarkable tubular networks of capsules in the extended structure. [ABSTRACT FROM AUTHOR]

Blue Ru(o-cat)[(P[Ph.sub.3].sub.3] (5; o-cat = ortho-catecholate), obtained in 94% yield by reaction of Ru[Cl.sub.2][(P[Ph.sub.3].sub.3] (4) with dithallium catecholate, was characterized by NMR, MALDI-MS, IR, and single crystal X-ray analysis, and by a combined electronic spectroscopy and time-dependent density functional theory (TD-DFT) study. The frontier orbitals in 5 participate in a low-energy charge transfer excitation involving donation from the Ru-catecholate π bond (largely localized on catecholate) to a low-lying σ* orbital on Ru-P[Ph.sub.3(apical)]. The energy of this transition increases on binding a pyridine ligand in the sixth site. Key words: ruthenium aryloxide, catecholate, phosphine, electronic spectroscopy, time-dependent DFT. Le Ru(o-cat)(P[Ph.sub.3]) bleu (5; o-cat = ortho-catecholate) qui est obtenu avec un rendement de 94% par reaction du Ru[Cl.sub.2][(P[Ph.sub.3]).sub.3] (4) avec le catecholate de dithallium a ete caracterise par RMN, spectrometrie de masse 'MALDI', spectroscopie IR et par diffraction des rayons X par un cristal unique ainsi que par une combinaison de spectroscopie electronique et d'une etude de theorie de la fonctionnelle de densite en fonction du temps. Les orbitales frontieres du produit 5 participent dans une excitation par transfert de charge de basse energie impliquant le don d'electron a partir de la liaison π du catecholate de ruthenium (principalement localisee sur le catecholate) vers une orbitale σ* de basse energie du Ru-P[Ph.sub.3(apical)]. L'energie de cette transition augmente lors de la fixation d'un ligand pyridine sur le sixieme site. Mots-cles : aryloxyde de ruthenium, catecholate, phosphine, spectroscopie electronique, theorie de la fonctionnelle de densite en fonction du temps. [Traduit par la Redaction] Monfette et al. 367, Introduction Olefin metathesis is now one of the most powerful methods in use for the construction of C=C bonds (1). Of the many well-defined catalysts developed for this versatile reaction, [...]

Naphthalene derived compounds that belong to the polycyclic aromatic hydrocarbons have significant importance in medicinal chemistry owing to their interesting biological activities. The structural knowledge of new naphthalene derived compounds can help in the understanding of their mechanism of action. In this study, we have investigated the molecular and structural landscape of three naphthalene-derived dications, namely, 1,1′-(naphthalene-2,6-diylbis(methylene))bis(3-methyl-1H-imidazolium), 1,1′-(naphthalene-2,7-diylbis(methylene))bis(3-methyl-1H-imidazolium) and 1,1′-(naphthalene-2,6-diylbis(methylene))bis(1-butylpyrrolidinium) as bromide salts. The structural details and non-covalent interactions for these structures were carefully examined using X-ray crystallography. Contributions to crystal packing from various types of intermolecular contacts were investigated and quantified using the Hirshfeld surface analysis. The backgrounds of these differences were analysed in terms of the key factors such as hydrogen bonding, the position of substituents appended on the naphthyl ring, and the presence of aromatic and non-aromatic moieties as substituents. The present work not only demonstrates how the position of the substituent group on the bicyclic ring influences the geometric conformation and overall packing, but also contributes toward a better understanding of how molecules self-assemble with respect to different functional groups (aromatic vs. non-aromatic). [ABSTRACT FROM AUTHOR]

The reaction of MnCl2·4H2O, H8L (2,2′-bis-p-tBu-calix[4]arene) and NEt3 in a dmf/MeOH solvent mixture results in the formation of a mixed valent decametallic cluster of formula [Mn II6 Mn III4 (L)2(μ3-OH)4(μ-OH)4(MeOH)4(dmf)4(MeCN)2]·MeCN (3). Complex 3 crystallises in the monoclinic space group P21/n with the asymmetric unit comprising half of the compound. Structure solution reveals that the bis-calix[4]arene ligands are arranged such that one TBC[4] moiety in each has undergone inversion in order to accommodate a [Mn III4 Mn II6 ] metallic skeleton that describes three vertex-sharing [Mn III2 Mn II2 ] butterflies. The structure is closely related to the species [Mn III6 Mn II4 (L)2(μ3-O)2(μ3-OH)2(μ-OMe)4(H2O)4(dmf)8]·4dmf (4), the major difference being the oxidation level of the Mn ions in the core of the compound. DFT calculations on the full structures reveal that replacing the MnIII ions in 4 for MnII ions in 3 results in a significant decrease in the magnitude of some antiferromagnetic exchange contributions, a switch from ferromagnetic to antiferromagnetic in others, and the loss of significant spin frustration. [ABSTRACT FROM AUTHOR]

Four multi-component complexes based on p-sulfonatocalix[4]arene anion, the methyltriphenylphosphonium cation, lanthanide ions (Gd(III)) and different ionic liquid-based cations (1-methyl-3-butylimidazolium, 1-methyl-3-octylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene) were synthesised and structurally characterised. Common bilayer arrangements are formed in the extended structures of all four complexes, though the bilayer thicknesses varies depending on the components involved. Molecular capsule formation is facilitated by the inclusion of methyltriphenylphosphonium, 1-methyl-3-butylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene cations, but not in the case of the 1-methyl-3-octylimidazolium cation. Molecular capsule size depends on the nature of the included guest cation, and methyltriphenylphosphonium cations fill compact spaces between calixarenes in these new bilayer arrays. [ABSTRACT FROM AUTHOR]

Two multi-component crystal structures comprising a carboxylic acid-functionalized imidazolium zwitterion, a p-sulfonatocalix[4]arene anion and aquated metal ion (Na+ or Y3+) with or without an auxiliary component (the 3-methoxyphenyl-triphenylphosphonium cation) are reported. The carboxylic acid-functionalized imidazolium ion binds either as a monodentate or a bidentate ligand depending on the nature of the metal ions, and a bi-layer arrangement prevails in the extended structure regardless of the type of metal ion employed or presence/lack of auxiliary component. [ABSTRACT FROM AUTHOR]

Reaction of 2,2′-bis-p-tBu-calix[4]arene (H8L) with MnCl2·4H2O, GdCl3·6H2O and 2,6-pyridinedimethanol (H2pdm) affords [MnIIIMnIIGdIII(H3L)(pdmH)(pdm)(MeOH)2(dmf)]·3MeCN·dmf (3·3MeCN·dmf) upon vapour diffusion of MeCN into the basic dmf/MeOH mother liquor. 3 crystallises in the tetragonal space group P41212 with the asymmetric unit comprising the entire cluster. The highly unusual core contains a triangular arrangement of MnIIIMnIIGdIII ions housed within a [MnIIIMnIIGdIII(OR)4]4− partial cubane. Magnetic susceptibility and magnetisation data reveal best fit parameters JMn(II)–Mn(III) = +0.415 cm−1, JMn(III)–Gd(III) = +0.221 cm−1, JMn(II)–Gd(III) = −0.258 cm−1 and DMn(III) = −4.139 cm−1. Theoretically derived magnetic exchange interactions, anisotropy parameters, and magneto-structural correlations for 3 are in excellent agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The reaction between MnCl2·4H2O, 2,2′-bis-p-tBu-calix[4]arene (H8L1) and 2-(hydroxymethyl)pyridine (hmpH) in a basic dmf/MeOH solution results in the formation of the complex [Mn III10 Mn II4 (L1)3(hmp)4(μ3-O)4(μ3-OH)2(MeOH)4(dmf)6](dmf)4 (6) upon vapour diffusion of petroleum ether into the mother liquor. The crystals are in the monoclinic space group C2/c, with the asymmetric unit (ASU) comprising one half of the molecule. The structure describes a large S-shaped cluster (∼40 Å top to tail) where the unusual syn and anti conformations of the calixarene ligands results in two binding pockets each containing a [Mn III5 Mn II2 ] moiety comprised of two perpendicular, vertex-sharing [Mn4] butterflies. One butterfly possesses a [Mn III4 O4] core and the second a [Mn III2 Mn II2 O3] unit with the MnII ions in the central body positions. Magnetic susceptibility and magnetisation measurements reveal weak exchange interactions between the metal centres. [ABSTRACT FROM AUTHOR]

The use of methylene-bridged calix[4]arenes in 3d/4f chemistry which produces a family of clusters of general formula [[Mn.sup.III.sub.4][Ln.sup.III.sub.4][(OH).sub.4][(C4).sub.4][(N[O.sub.3]).sub.2][(DMF).sub.6][([H.sub.2]O).sub.6]](OH)2 (where C4 = calix[4]arene and Ln = Gd , Tb, Dy) is demonstrated. The replacement of the isotropic [Gd.sup.III] ions with the anisotropic [Tb.sup.III] and [Dy.sup.III] ions 'switches' the magnetic properties of the cluster to make the complexes Tb and Dy to behave as low-temperature molecular magnets and could be applied as an excellent magnetic refrigerant for low-temperature applications.

Clarithromycin is an antibiotic that is present in various polymorphic forms. This molecule is sublimed to produce a guest-free form that has displayed the unexpected transport of molecules of water or carbon dioxide to voids within the channel-free crystal lattice.

Experiments have shown that metal ions and ion pairs can move through aqueous structural gates to the interior of pyragallo[4]arene metal-organic nanocapsules. The action of metal-organic polyhedra is described as synthetic ion channels that can transport alkali metal ions across lipid membranes.

Coordination solids are designed and developed based on a tetrahedral organic linker, tetrakis[4-(carboxyphenyl)oxamethyl]methane, as a building block to generate metal-organic frameworks (MOFs) with metal salts and organic pillars. High selectivity for C[O.sub.2] over [H.sub.2] and [N.sub.2] is a necessity if these materials should be used for C[O.sub.2] separations from synthesis gas and flue gas mixtures.

The investigation of inner phase properties of the pyrogallol[4]arenes hexamer by using the solvent-dependent properties of 1-(9-anthryl)-3-(4-dimethylaniline) propane (ADMA) indicated the majority of ADMA to be sequestered in an extended conformation with the crystallization solvent.