Josefina Perles

Rare-earths as catalytic centres in organo-inorganic polymeric frameworksElectronic supplementary information (ESI) available: selected bond angles and hydrogen interactions in 1, 2, 3; coordination environment of the two scandium atoms in 1; coordination modes of the three crystallographically independent carboxylate groups for 2 and 3. See http://www.rsc.org/suppdata/jm/b3/b314220e/

New 3D polymeric succinates of rare-earths have been synthesised: [Sc2(C4H4O4)2.5(OH)], [Y2(C4H4O4)3(H2O)2]·H2O, [La2(C4H4O4)3(H2O)2]·H2O, and their structures solved by single crystal XRD. They were obtained as single phases, characterised and tested as heterogeneous catalysts as Lewis acids in the acetalization of aldehydes and as redox agents in the oxidation of sulfides showing them to be effective and selective catalysts, easy to recover and reusable. The scandium, yttrium and lanthanum oxides were also tested in the same catalytic reactions to prove the effect of the porous organo-inorganic framework.

3D scandium and yttrium arenedisulfonate MOF materials as highly thermally stable bifunctional heterogeneous catalysts

Three new 3D metal-organic frameworks (MOFs), namely scandium and yttrium naphthalenedisulfonates (nds), have been obtained and their crystal structures have been determined by single crystal X-ray diffraction. The 1,5- and 2,6-nds scandium compounds (RPF-12 and RPF-13, respectively), both with the formula [Sc2(nds)(OH)4]n, and the yttrium naphthalenedisulfonate [Y(1,5-nds)(OH)(H2O)]n, RPF-14, were synthesised under hydrothermal conditions. The frameworks can be described as pillared layered motifs where sheets of sulfonate bridged polyhedra are connected by naphthalene units. The scandium disulfonate [Sc2(2,6-nds)(OH)4]n is the first obtained rare-earth 2,6-nds MOF with the same stoichiometry and arrangement as its 1,5-nds counterpart. The new MOFs, with high thermal stability, act as active and selective bifunctional heterogeneous catalysts in the epoxidation of linalool and oxidation of sulfides.

Bridged 3,5-disubstituted pyrazolate ligands as support of metallomesogens containing [Pd(η3-C3H5)]+ fragments: X-ray crystal structure of [Pd(η3-C3H5)(μ-pzR2)]2·CH2Cl2 (R=C6H4OC12H25). Part III

Abstract The mesomorphic properties of two new long-chain 3,5-(4-n-alkoxyphenyl)pyrazoles HpzR2 (R=C6H4OCnH2n+1, n=16, 18) have been studied and compared with those of related compounds containing shorter chains (n=4, 6, 8, 10, 12, 14). For liquid crystal purposes, the derivative with 14 carbon atoms in the chain behaves as the best compound on the basis of the lowest melting point and the widest stability range of the mesophases. New Pd(II) complexes of formula [Pd(η3-C3H5)(μ-pzR2)]2 (R=C6H4OCnH2n+1, n=8, 10, 12, 14, 16, 18) (1–6) containing the mesomorphic ligands as pyrazolate-bridging groups have been prepared and characterised. In solution, three conformational isomers (two symmetric and one asymmetric corresponding to different orientations of the allyl groups) have been found. In the solid state, the X-ray crystal structure of 3 (n=12) evidenced the asymmetric isomer. The structure shows a bowlic core drawn on the basis of the boat-like conformation of the six-membered ring Pd(NN)2Pd. However, a rod-like shape could also be considered by taking the molecular dimensionality into account (47.80 A in length×4.75 A in wide). The Pd-complexes 2–6 were found to have liquid crystal properties exhibiting enantiotropic smectic phases consistent with the molecular characteristics. Moreover, the molecular packing of 3 is described as the layer-like type in which the molecules are parallel to the c-axis but tilted off the layer, this fact appearing similar to the molecular ordering in the smectic fluid phases.

First microwave synthesis of multiple metal-metal bond paddlewheel compounds

A green and efficient microwave assisted synthesis of elusive tetrakis(diaryltriazenido)diruthenium(II) complexes was carried out under microwave irradiation. It is a simple, clean, and fast method that proceeds with good yield, in contrast with the poor ones reported in previous syntheses.

Copper Complexes with New Pyridylpyrazole Based Ligands

We report the synthesis, characterization, and crystal structures of new ligands of the pyridinylpyrazole type, i.e., 3,5-bis(4-butoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole (L1) and 3,5-bis(4-phenoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole (L2) (Scheme 1), and the study of their coordination behavior towards CuI and CuII. The versatility of this type of ligand, which can give access to different coordination spheres about the metal center, depending on the nature of the copper starting material used in the preparation of the complexes (Scheme 2), is illustrated. Thus, pseudo-tetrahedral CuI as well as six-coordinated tetragonal and distorted tetragonal pyramidal CuII derivatives were obtained for [Cu(L)2]PF6, [Cu(Cl)2(L)2] (L=L1, L2), and [Cu(Cl)(L1)2]PF6, respectively. We also present a crystallographic support of a distorted octahedral cis-bis(tetrafluoroborato-κF)copper(II) compound found for [Cu(BF4)2(L1)2] (3).

Oxidation of anticancer Pt(II) complexes with monodentate phosphane ligands: towards stable but active Pt(IV) prodrugs

The synthesis, characterization and cytotoxicity studies of two novel platinum(IV) complexes, trans-PtCl4(dma)(PPh3), 1, and trans-PtCl4(ipa)(PPh3), 2, where dma is dimethylamine and ipa is isopropylamine, have been carried out. Both complexes contain aliphatic amines trans to phosphane ligands as a good alternative to take advantage of the phosphane group lipophilicity and the stability of platinum(IV) to obtain more effective drugs. Moreover, the complexes are stable in solution and such stability allowed their antitumoral action and DNA interaction to be checked and proved.

Investigation of Structural Characteristics of Bis(β-diketonato)copper(II) Complexes Containing Alkoxy or Aryloxy Side Chains: X-Ray Structures of 1,3-Bis(4-butoxyphenyl)propane-1,3-dione, Bis[1,3-bis(4-butoxyphenyl)propane-1,3-dionato-κO,κO′]copper(II) and Bis[1,3-bis(4-phenoxyphenyl)propane-1,3-dionato-κO,κO′]copper(II)

Copper(II) complexes containing β-diketonato ligands of the general formula [Cu{(4-RO)C6H4COCHCOC6H4(4-OR)}2] 3 (R=Bu) or 4 (R=Ph) were prepared and their structures solved by X-ray diffraction. The crystal structure of the parent ligand (4-BuO)C6H4COCH2COC6H4(4-OBu) 1 was also solved. The influence of the different side chains 4-RO−C6H4 (R=Bu or Ph) on potential liquid-crystal properties was investigated for both the ligands and the copper derivatives. The presence of BuO substituents at the aromatic rings appears to improve the molecular linearity with respect to 1,3-diphenylpropane-1,3-dione (=dibenzoylmethane; DBM), this feature being of interest for rod-like structures. On the other hand, the molecular structure of the copper(II) complexes 3 and 4 showed a flat core almost unmodified by the different peripherical substituents. A columnar arrangement was observed for both compounds 3 and 4, but, additionally, a layer-like disposition was also found in 3, which was proved to be a metallomesogen.

Reversible recrystallization process of copper and silver thioacetamide-halide coordination polymers and their basic building blocks†

Three-dimensional [CuX(TAA)]n (X = Br (1), I (2)) and bi-dimensional [AgX(TAA)]n (X = Cl (3), Br (4)) coordination polymers have been isolated by the direct synthesis from copper(I) and silver(I) halides and thioacetamide (TAA). These are multifunctional materials showing electrical conductivity (values at room temperature ranging from 7 × 10−6 to 2 × 10−9 S cm−1) and luminescence in the blue region. The unusual solubility of 1–4 in different solvents and the recrystallization process observed for 1 and 2 in acetonitrile and for 3 and 4 in pyridine have been measured. We show preliminary results of the processability of 2 on glass for the production of organized thin films. These results are very attractive for the processability of coordination polymers in materials science and nanoscience.

Luminescent Thermochromism of 2D Coordination Polymers Based on Copper(I) Halides with 4‐Hydroxythiophenol

Solvothermal reactions between copper(I) halides and 4-mercaptophenol give rise to the formation of three coordination polymers with general formula [Cu3 X(HT)2 ]n (X=Cl, 1; Br, 2; and I, 3). The structures of these coordination polymers have been determined by X-ray diffraction at both room- and low temperature (110 K), showing a general shortening in Cu-S, Cu-X and Cu-Cu bond lengths at low temperatures. 1 and 2 are isostructural, consisting of layers in which the halogen ligands act as μ3 -bridges joining two Cu1 and one Cu2 atoms whereas in 3 the iodine ligands is as μ4 -mode but the layers are quasi-isostructural with 1 or 2. These compounds show a reversible thermochromic luminescence, with strong orange emission for 1 and 2, but weaker for 3 at room temperature, whereas upon cooling at 77 K 1 and 2 show stronger yellow emission, and 3 displays stronger green emission. DFT calculations have been used to rationalize these observations. These results suggest a high potential for this novel and promising stimuli-responsive materials.

A structural and biological study on the new 3,5-diacetyl-1,2,4-triazol bis(p-chlorophenylthiosemicarbazone) ligand and its bimetallic complexes

Preparation and characterization of the new ligand 3,5-diacetyl-1,2,4-triazol bis(4N-p-chlorophenylthiosemicarbazone), H5L1, and its bimetallic complexes [Pd(μ-H3L1)]2 and [Pt(μ-H3L1)]2, are described. The molecular structure of the complexes, determined by single crystal X-ray crystallography, reveals that each ligand coordinates, in an asymmetric dideprotonated form, to the metal ions in a square planar geometry. The new compounds synthesized have been evaluated for antiproliferative activity in vitro against NCI-H460, T-47D, A2780 and A2780cisR human cancer cell lines. The cytotoxicity data suggest that these compounds may be endowed with important antitumor properties, especially H5L1, since they exhibit excellent antiproliferative activity surpassing the activity of cisplatin against three of the four tumor cell lines studied. The DNA binding ability of H5L1 and [Pt(μ-H3L1)]2 with calf thymus DNA in Tris-HCl buffer solution (pH = 7.2) was explored by UV-Vis absorption spectroscopy and viscosity measurements. These data indicated that both compounds bind to DNA by a groove binding mode.