Synthesis of new polymetallic iron(III) clusters containing polycarboxylate ligands based on cavity-blocked cyclen

The synthesis and magnetic properties of enneametallic and octametallic Fe(III) cage complexes from tetraazamacrocycle ligands (1,7-H2DO2A) and (H3DO3A) respectively, are reported.     

Synthesis and characterization of gold nanoparticles stabilized by palladium(II) phosphine thiol

This work is focused on the synthesis of innovative hybrids made by linking gold nanoparticles to protected organometallic Pd(II) thiolate. The organometallic protected Pd(II) thiolate, i.e. trans-thioacetate-ethynylphenyl-bis(tributylphosphine)palladium(II) has been synthesized, in situ deprotected and linked to Au nanoparticles. In this way new hybrid, with a direct link between Pd(II) and Au nanoparticles through a single S bridge, has been isolated. The combination of the organometallic Pd(II) thiol with gold nanoparticles allows the enhancement and tailoring of electronic and optical properties of the new organic-inorganic nano-compound. Single-crystal gold nanoparticles, uniform in shape and size were obtained by applying a modified two-phase method (improved Brust-Schiffrin reaction). In addition, the chemical environment of the Au nanoparticles was investigated and a covalent bonding between Au nanoparticles and the organometallic thiols was observed.     

One-dimensional and two-dimensional coordination polymers constructed from copper(II) nodes and polycarboxylato spacers: Synthesis,crystal structures and magnetic properties

Four new coordination polymers were obtained by employing polycarboxylato spacers and cationic copper(II) complexes as nodes: ^∞₂[Cu₃(trim)₂(NH₃)₆(H₂O)₃] (1); ^∞₁[Cu(tmen)(dhtp)] (2), ^∞₁[Cu(tmen)(hitp)(H₂O)] (3), ^∞₁[Cu(tmen)(nitp)] (4). (H₃trim = trimesic acid, H₂dhtp = 2,5-dihydroxy-terephthalic acid; H₂hitp = 5-hydroxy-isophthalic acid, H₂nitp = 5-nitro-isophthalic acid; tmen = N,N,N′,N′-tetramethyl-ethylenediamine). The crystal structures of the four compounds have been solved. Compound 1 consists of 2D coordination polymers with heart-shaped meshes, while compounds 2–4 contain infinite zigzag chains. The role of the hydrogen bond interactions in sustaining the supramolecular solid-state architectures in compounds 1 and 3 is discussed. The cryomagnetic investigation of compounds 1, 2, and 4 reveals antiferromagnetic interactions between the copper ions.     

Co-Ln mixed-metal phosphonate grids and cages as molecular magnetic refrigerants

The synthesis, structures, and magnetic properties of six families of cobalt-lanthanide mixed-metal phosphonate complexes are reported in this Article. These six families can be divided into two structural types: grids, where the metal centers lie in a single plane, and cages. The grids include [4 × 3] {Co(8)Ln(4)}, [3 × 3] {Co(4)Ln(6)}, and [2 × 2] {Co(4)Ln(2)} families and a [4 × 4] {Co(8)Ln(8)} family where the central 2 × 2 square is rotated with respect to the external square. The cages include {Co(6)Ln(8)} and {Co(8)Ln(2)} families. Magnetic studies have been performed for these compounds, and for each family, the maximum magnetocaloric effect (MCE) has been observed for the Ln = Gd derivative, with a smaller MCE for the compounds containing magnetically anisotropic 4f-ions. The resulting entropy changes of the gadolinium derivatives are (for 3 K and 7 T) 11.8 J kg(-1) K(-1) for {Co(8)Gd(2)}; 20.0 J kg(-1) K(-1) for {Co(4)Gd(2)}; 21.1 J kg(-1) K(-1) for {Co(8)Gd(4)}; 21.4 J kg(-1) K(-1) for {Co(8)Gd(8)}; 23.6 J kg(-1) K(-1) for {Co(4)Gd(6)}; and 28.6 J kg(-1) K(-1) for {Co(6)Gd(8)}, from which we can see these values are proportional to the percentage of the gadolinium in the core.     

Technical improvement of the TBP (tubulin‐based polymorphism) method for plant species detection,based on capillary electrophoresis

Nowadays, feed and food safety and traceability are of primary importance. Hence, a correct labeling of the different products is highly desirable in general, but mandatory for those people who are suffering from eating disorders and food allergies. Among the technologies that have been developed for feed and food analysis, the patented tubulin‐based polymorphism (TBP) method emerges as an easy, versatile, and inexpensive diagnostic tool. Initially used to fingerprint different plant species and varieties, TBP was then successfully applied to trace species in mixtures of plant origin such as commercial feeds. TBP is a DNA‐based molecular marker, that makes use of PCR for the selective amplification of plant β‐tubulin introns. Amplified fragments are then separated by PAGE and visualized by silver staining. We have now developed an improved version of TBP. Based on capillary electrophoresis and fluorescence detection, it makes the method automatic, more sensible, reproducible, and faster. Compared to the classic TBP, this new version allows to obtain a better data resolution and an easier interpretation of the results, clearing the way to large‐scale feed/food diagnostics.     

A novel piecewise multivariate function approximation method via universal matrix representation

Multivariance in science and engineering causes problematic situations even for continous and discrete cases. One way to overcome this situation is to decrease the multivariance level of the problem by using a divide—and—conquer based method. In this sense, Enhanced Multivariance Product Representation (EMPR) plays a part in the considered scenario and acts successfully. This method brings up a finite expansion to represent a multivariate function in terms of less-variate functions with the assistance of univariate support functions. This work aims to propose a new EMPR based algorithm which has two new features that improves the determination process of each expansion component through Fluctuation Free Integration method, which is an efficient method in evaluating multiple integrals through a universal matrix representation, and increases the approximation quality through inserting a piecewise structure into the standard EMPR algorithm. This new method is called Fluctuation Free Integration based piecewise EMPR. Some numerical implementations are also given to examine the performance of this proposed method.