Poly[tris­(μ3-5-amino­isophthalato)diaqua­dicerium(III)]

In the title complex, [Ce2(C8H5NO4)3(H2O)2]n, each Ce ion is in nine-coordinated environment. Eight O atoms from six ligands participate in coordination, in addition to one O atom from a water mol­ecule. Both carboxyl­ate groups from the ligands chelate the Ce atoms, forming two four-membered rings. The 5-amino­isophthalate ligands also bridge the Ce centers, forming a two-dimensional network, and O—H⋯O and N—H⋯O hydrogen bonds complete the structure

catena-Poly[[(1,10-phenanthroline-κ2 N,N′)praseodymium(III)]-di-μ-phenoxy­acetato-κ4 O:O′-[(1,10-phenanthroline-κ2 N,N′)praseodymium(III)]-di-μ-phenoxy­acetato-κ4 O:O′-di-μ-phenoxy­acetato-κ3 O,O′:O;κ3 O:O,O′]

The title complex, [Pr2(C8H7O3)6(C12H8N2)2]n, which has an inversion centre midway between the two PrIII atoms of the structural unit, forms a one-dimensional polymer bridged alternately by either two bidentate, or two bidentate and two terdentate, phenoxy­acetate carboxyl­ate groups. Each PrIII atom is thus nine-coordinated by two N atoms of a 1,10-phenanthroline ligand and seven O atoms from six phenoxy­acetate ligands. The coordination geometry at the PrIII atom is distorted tricapped trigonal prismatic. One phenyl ring is disordered over two positions; the site occupancy factors are ca 0.6 and 0.4

Luminescence tuning of MOFs via ligand to metal and metal to metal energy transfer by co-doping of 2∞[Gd2Cl6(bipy)3]*2bipy with europium and terbium

The series of anhydrous lanthanide chlorides LnCl3, Ln=Pr–Tb, and 4,4'-bipyridine (bipy) constitute isotypic MOFs of the formula 2∞[Ln2Cl6(bipy)3]*2bipy. The europium and terbium containing compounds both exhibit luminescence of the referring trivalent lanthanide ions, giving a red luminescence for Eu3+ and a green luminescence for Tb3+ triggered by an efficient antenna effect of the 4,4'-bipyridine linkers. Mixing of different lanthanides in one MOF structure was undertaken to investigate the potential of this MOF system for colour tuning of the luminescence. Based on the gadolinium containing compound, co-doping with different amounts of europium and terbium proves successful and yields solid solutions of the formula 2∞[Gd2-x-yEuxTbyCl6(bipy)3]*2bipy (1–8), 0≤x, y≤0.5. The series of MOFs exhibits the opportunity of tuning the emission colour in-between green and red. Depending on the atomic ratio Gd:Eu:Tb, the yellow region was covered for the first time for an oxygen/carboxylate-free MOF system. In addition to a ligand to metal energy transfer (LMET) from the lowest ligand-centered triplet state of 4,4'-bipyridine, a metal to metal energy transfer (MMET) between 4f-levels from Tb3+ to Eu3+ is as well vital for the emission colour. However, no involvement of Gd3+ in energy transfers is observed rendering it a suitable host lattice ion and connectivity centre for diluting the other two rare earth ions in the solid state. The materials retain their luminescence during activation of the MOFs for microporosity

Protein crystallization in short-peptide supramolecular hydrogels: A versatile strategy towards biotechnological composite materials

Protein crystallization in hydrogels has been explored with the main purpose of facilitating the growth of high quality crystals while increasing their size to enhance their manipulation. New avenues are currently being built for the use of protein crystals as source materials to create sensors and drug delivery vehicles, to name just a few. In this sense, short-peptide supramolecular hydrogels may play a crucial role in integrating protein crystals within a wider range of applications. In this article, we show that protein crystallization in short-peptide supramolecular hydrogels is feasible and independent of the type of peptide that forms the hydrogel and/or the protein, although the output is not always the same. As a general trend, it is confirmed that hydrogel fibers are always incorporated within crystals so that novel composite materials for biotechnological applications with enhanced properties are produced.This research was funded by the MICINN (Spain) projects BIO2010-6800 (JAG), CTQ2012-34778 (JJDM), and “Factoría Española de Cristalización” Consolider-Ingenio 2010 (JAG & MCM), and by Junta de Andalucía (Spain) project P12-FQM- 2721 (LAC). EDRF funds JAG, LAC & JMC. JJDM thanks MICINN for a Ramon y Cajal Fellowship and MCM thanks CSIC for her JAE Fellowshi

Three-dimensional lanthanide-organic frameworks based on di-, tetra-, and hexameric clusters

Three-dimensional lanthanide-organic frameworks formulated as (CH3)2NH2[Ln(pydc)2] · 1/2H2O [Ln3+ ) Eu3+ (1a) or Er3+ (1b); pydc2- corresponds to the diprotonated residue of 2,5-pyridinedicarboxylic acid (H2pydc)], [Er4(OH)4(pydc)4(H2O)3] ·H2O (2), and [PrIII 2PrIV 1.25O(OH)3(pydc)3] (3) have been isolated from typical solvothermal (1a and 1b in N,N-dimethylformamide - DMF) and hydrothermal (2 and 3) syntheses. Materials were characterized in the solid state using single-crystal X-ray diffraction, thermogravimetric analysis, vibrational spectroscopy (FT-IR and FT-Raman), electron microscopy, and CHN elemental analysis. While synthesis in DMF promotes the formation of centrosymmetric dimeric units, which act as building blocks in the construction of anionic ∞ 3{[Ln(pydc)2]-} frameworks having the channels filled by the charge-balancing (CH3)2NH2 + cations generated in situ by the solvolysis of DMF, the use of water as the solvent medium promotes clustering of the lanthanide centers: structures of 2 and 3 contain instead tetrameric [Er4(μ3-OH)4]8+ and hexameric |Pr6(μ3-O)2(μ3-OH)6| clusters which act as the building blocks of the networks, and are bridged by the H2-xpydcx- residues. It is demonstrated that this modular approach is reflected in the topological nature of the materials inducing 4-, 8-, and 14-connected uninodal networks (the nodes being the centers of gravity of the clusters) with topologies identical to those of diamond (family 1), and framework types bct (for 2) and bcu-x (for 3), respectively. The thermogravimetric studies of compound 3 further reveal a significant weight increase between ambient temperature and 450 °C with this being correlated with the uptake of oxygen from the surrounding environment by the praseodymium oxide inorganic core

Influence of the chirality of short peptide supramolecular hydrogels in protein crystallogenesis

For the first time the influence of the chirality of the gel fibers in protein crystallogenesis has been studied. Enantiomeric hydrogels 1 and 2 were tested with model proteins lysozyme and glucose isomerase and a formamidase from B. cereus. Crystallization behaviour and crystal quality of these proteins in both hydrogels are presented and compared.MICINN (Spain) projects BIO2010-16800 (JAG), CTQ-2011.22455 (LAC & JMC), CTQ2012-34778 (JJDM & ALG), “Factoría Española de Cristalización” Consolider-Ingenio 2010 (JAG & MCM) and EDRF Funds (JAG, LAC & JMC), P12-FQM-2721 (LAC) Junta de Andalucía.MINECO,Project No. FIS2013-41821-R

Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.Kang Liang, Raffaele Ricco, Cara M. Doherty, Mark J. Styles, Stephen Bell, Nigel Kirby, Stephen Mudie, David Haylock, Anita J. Hill, Christian J. Doonan, Paolo Falcar

Structural and Near-IR Luminescent Properties of Erbium-Containing Coordination Polymers

International audienceThe near-IR luminescence properties of two ErIII-containing coordination polymers, namely, [Er(btc)(H2O)5·3.5H2O] [(btc)3– = 1,3,5-benzenetricarboxylate] and [Er2(bdc)3- (H2O)4] [(bdc)2– = 1,4-benzenedicarboxylate] were investigated with the aim of testing their potential use as optical materials. Because both present relatively small quantum yields and short excited-state lifetimes, factors influencing their luminescent properties were deciphered in an effort to improve their luminescent properties. Thus, three other families of compounds were also investigated: (i) the two corre-sponding dehydrated compounds with respective chemical formula [Er(btc)] and [Er2(bdc)3] for evaluating the importance of O–H vibrators, (ii) the heterodinuclear compounds [Er2–2xY2x(bdc)3(H2O)4] (x = 0.2, 0.5, 0.8 and 0.9) for estimating the role of intermetallic quenching and (iii) the heterodinuclear compounds [Er2–2xYb2x(bdc)3(H2O)4] (x = 0.2 and 0.5) for checking whether YbIII-sensitized up-conversion can be induced or not. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

MATERIAUX MOLECULAIRES A BASE DE LANTHANIDES (DE LA SYNTHESE A L'ARCHITECTURE CRISTALLINE)

CE DOCUMENT CONSACRE A LA CHIMIE DES SYSTEMES MOLECULAIRES A BASE D'IONS LANTHANIDES EST ORGANISE EN TROIS PARTIES. LA PREMIERE PARTIE EST CONSTITUEE D'UNE COURTE REVUE DES PROPRIETES CHIMIQUES ET PHYSIQUES DES IONS LANTHANIDES EN SOLUTION, D'UNE REVUE EXHAUSTIVE DES SYSTEMES MOLECULAIRES MIXTES 4F-3D DECRITS DANS LA LITTERATURE DEPUIS 1995 ( 100 REF.). ELLE SE TERMINE PAR UN EXPOSE DE NOS TRAVAUX CONSACRES A LA CRISTALLOGENESE. LA SECONDE PARTIE EST CONSACREE A LA SYNTHESE D'OXALATES MIXTES LN I I I-CR I I I, LN I I I-CU I I, LN I I I-FE I I I ET A LEUR IDENTIFICATION PAR DIAGRAMME DE RAYONS X SUR POUDRE. ELLE COMPORTE, DE PLUS, LA CARACTERISATION STRUCTURALE ET LA DESCRIPTION DES PROPRIETES MAGNETIQUES DU PREMIER COMPOSE MOLECULAIRE MIXTE LN I I I-CU I I BIDIMENSIONNEL : LE SYSTEME LN 2(CUOPBA) 1 / 2(CUOX 1 / 2 3.9DMF.4,5DMF AVEC LN = LA-GD. LA TROISIEME PARTIE, ENFIN, EST CONSACREE A L'ETUDE CRISTALLOCHIMIQUE ET THERMIQUE DES SYSTEMES LNTMA.NH 2O ET LNCHA.NH 2O, OU H 3TMA REPRESENTE L'ACIDE BENZENE-1,3,5-TRICARBOXYLIQUE ET H 3CHA L'ACIDE CYCLOHEXANE-1,3,5-TRICARBOXYLIQUE. CETTE ETUDE COMPREND LA SYNTHESE ET LA CARACTERISATION STRUCTURALE DE SIX FAMILLES DE COMPOSES DE FORMULE : 1 LNTMA(H 2O) 6 AVEC LN = LA A DY, Y ET ER ; 2 LNTMA(H 2O) 3.1,5H 2O AVEC LN = GD, TB, DY ET ER ; 3 LNTMA(H 2O) 5.3,5H 2O AVEC LN = HO, Y, ER ET YB ; 4 LN 3TMA 3(H 2O) 8.4H 2O AVEC LN = ER ; 5 LN 2(CO 3) 3.8H 2O AVEC LN = LA ET CE ; 6 LNCHA(H 2O) 2.2,5H 2O AVEC LN = DY A YB. L'ETUDE CRISTALLOCHIMIQUE DETAILLEE DE CES COMPOSES A ETE EFFECTUEE A L'AIDE DU CONE PACKING MODEL QUI EST UNE ADAPTATION DU MODELE DE C.A. TOLMAN ET SEMBLE INDIQUER QUE L'OBTENTION DE SYSTEMES TRIDIMENSIONNELS EST IMPOSSIBLE SANS L'UTILISATION DE LIGANDS NON PLANS EN MILIEU AQUEUX OU CELLE DE SOLVANTS DE TAILLE COMPARABLE A CELLE DES LIGANDS. ENFIN, L'ETUDE THERMIQUE DU SYSTEME LNTMA.NH 2O MET EN AVANT L'EXISTENCE D'UN CYCLE DE DESHYDRATATION-REHYDRATATION CONTENANT PLUSIEURS DES STRUCTURES CARACTERISEES PRECEDEMMENT AINSI QU'UNE PHASE ANHYDRE DE FORMULE LNTMA.RENNES-INSA (352382210) / SudocSudocFranceF