Unravelling the spin-state of solvated [Fe(bpp)2] 2+ spin-crossover complexes: structure-function relationship

This is the Accepted Manuscript of the following article:M. D. C. Gimenez Lopez, M. Clemente Leon and C. Giménez-Saiz, Dalton Trans., 2018, DOI: 10.1039/C8DT01269EThe authors acknowledge the Royal Society (DH110080 fellowship for M.C.G-L.), the European Research Council (ERC StG-679124 for M.C.G-L.) and the Generalitat Valenciana for funding this workS

Fe(II) spin crossover complexes of a derivative of 2,6-bis(pyrazol-1-yl)pyridine (1-bpp) functionalized with a carboxylic acid in the 3-pyridyl position

The preparation of a new bis(pyrazol-1-yl)pyridine (1-bpp) derivative functionalized with a carboxylic acid in the 3-pyridyl position, bpp3-COOH ligand is reported together with the structure and spin-crossover (SCO) properties of [FeII(bpp3-COOH)2](ClO4)2·0.5EtOH·0.5H2O (1). Magnetic properties of 1 indicate that LS is favored. Desolvation leads to a gradual and incomplete SCO. Solvated and desolvated compounds show LIESST effect

Intercalation of decamethylferrocenium cations in bimetallic oxalate-bridged two-dimensional magnets

The structure and magnetic properties of novel hybrid molecule-based magnets formed by combination of two magnetically active sublattices, the bimetallic oxalatobridged honeycomb net [MnIIMIII(ox)3] (MII = Mn, Fe, Co, Cr, Ni, Cu; MIII = Cr, Fe) and the organometallic cation decamethylferrocenium, are reported.Clemente Leon, Miguel, [email protected] ; Coronado Miralles, Eugenio, [email protected] ; Galan Mascaros, Jose Ramon, [email protected] ; Gomez Garcia, Carlos Jose, [email protected]

Electrochromic polyoxometalate material as a sensor of bacterial activity

L. fermentum, a bacterium of human microbiota, acts as an electron donor to the electrochromic [P2MoVI18O62]6. Since, the reductive capacity of L. fermentum correlates with its metabolic activity, the reaction with [P2MoVI18O62]6- affords a means of evaluating its activity. Following this logic, we have concluded that vancomycin severely affects the activity of L. fermentum whereas omeprazole does not.FQM368 Bionanopartículas Metálicas (BioNanomet)Departamento de Química InorgánicaThis work was funded by MINECO and FEDER (project CTQ2012-32236

Spin-crossover iron (II) complex showing thermal hysteresis around room temperature with symmetry breaking and an unusually high T(LIESST) of 120 K

We report a Fe(II) complex based on 4′,4′′ carboxylic acid disubstituted dipyrazolylpyridine that shows a spin-crossover close to room temperature associated to a crystallographic phase transition and the LIESST effect with a high T(LIESST) of 120 K

Spin-Crossover Grafted Monolayer of a Co(II) Terpyridine Derivative Functionalized with Carboxylic Acid Groups

The synthesis and characterization of a new Co(II) spin-crossover (SCO) complex based on 4′-(4-carboxyphenyl)−2,2′:6′,2″-terpyridine ligand are reported. This complex can be successfully grafted on silver surface maintaining the SCO behavior. Thus, atomic force microscopy (AFM), matrix assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF MS), Raman spectroscopy, and XPS measurements, upon surface deposition, evidence the formation of a monolayer of intact molecules grafted through carboxylate groups to the Ag surface. Three different techniques: Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), supported by first-principles calculations, confirm that the deposited molecules undergo a gradual spin transition with temperature. This phenomenon is unprecedented for a monolayer of molecules directly grafted onto a metallic surface from solution

Spin-crossover compounds based on iron(II) complexes of 2,6-bis(pyrazol-1-yl)pyridine (bpp) functionalized with carboxylic acid and ethyl carboxylic acid

Four new salts of the iron(II) complex of the 2,6-bis( pyrazol-1-yl)pyridine ligand functionalized with a carboxylic acid group (bppCOOH) of formulas [Fe(bppCOOH)2](BF4)2 (1(BF4)2), [Fe(bppCOOH)2] (CF3SO3)2·yMe2CO (1(CF3SO3)2·yMe2CO), [Fe(bppCOOH)2](AsF6)2·yMe2CO (1(AsF6)2·yMe2CO) and [Fe (bppCOOH)2](SbF6)2·yMe2CO (1(SbF6)2·yMe2CO) have been prepared and characterized together with a more complete structural and photomagnetic characterization of the previously reported [Fe (bppCOOH)2](ClO4)2 (1(ClO4)2). Furthermore, the iron(II) complex of the ethyl ester derivative of bppCOOH (bppCOOEt) has been prepared and characterized (compound [Fe(bppCOOEt)2] (ClO4)2·yMe2CO, 2(ClO4)2·yMe2CO). Isostructural 1(BF4)2 and 1(ClO4)2 show an abrupt and reversible spin transition with a much lower T1/2 for the BF4− salt. CF3SO3 , SbF6 and AsF6 counteranions and the bppCOOEt ligand lead to the incorporation of solvent molecules in the structures, which play an important role in the spin-crossover properties of these compounds. In the case of 1(CF3SO3)2·yMe2CO, a spin transition is obtained after desolvation. All these compounds show a LIESST effect

Influence of Proton Conducting Cations on the Structure and Properties of 2D Anilate-Based Magnets

The syntheses, structures, magnetic, and proton conductivity properties of a family of bimetallic anilate-based compounds with inserted alkylammonium cations are presented. The structures of (Me2NH2)[MnIICrIII(Br2An)3]·2H2O (1), (Et2NH2)[MnIICrIII(Br2An)3] (2), (Et3NH)[MnIICrIII(Cl2An)3] (3), and [(Et)(i-Pr)2NH]-[MnIICrIII(Br2An)3]·(CHCl3)0.5·(H2O) (4) contain a 2D anionic network formed by Mn(II) and Cr(III) ions linked through anilate ligands. In 1, 2, and 3, the hexagonal holes of this network are occupied by Me2NH2+, Et2NH2+, or Et3NH+ cations. Interestingly, the small increase of size of the templating cation in 4 ([(Et)(i-Pr)2NH]+ in the place of Me2NH2+, Et2NH2+ or Et3NH+), gives rise to a different structure with half of the cations placed within the layers and the other one in the space between the layers. This leads to bilayers with an interlayer separation similar to those of 1, 2, and 3 separated by larger interbilayer distances. Compounds 1, 2, and 3 show a ferrimagnetic ordering with a Tc of 8.0 K (1), 8.9 K (2), and 8.0 K (3). In 4, the presence of different interlayer distances leads to a metamagnetic behavior when the sample is measured in contact with the mother liquor. The behavior changes in the dry sample, which shows a ferrimagnetic ordering as that of 1, 2, and 3 due to collapse of the structure as confirmed by powder X-ray diffraction. Interestingly, the metamagnetic behavior is recovered after reimmersing the crystals in the mother liquor proving the reversibility of the process. All solids are Grotthuss-type proton conductors with conductivity values ranging between 2.3 × 10−6 S·cm−1 for 3 and 2.4 × 10−5 S·cm−1 for 1 measured at 70 °C and 95% relative humidity and activation energies of ∼0.2 eV.EU (ERC Advanced Grant SPINMOL) CTQ2014-52758-P, MAT-2014-56143-R y MAT2016-77648-R del MINECO Unidad de Excelencia María de Maeztu MDM-2015-0538 de la Generalitat Valenciana P12-FQM-1656 de la Junta de Andalucí

O conhecimento matemático do professor sobre a parábola: desenho de um instrumento para investigação

Research in mathematics education usually focuses on sharing results from the application of instruments to obtain data. Even though these instruments are usually described in the methodology section, their development process tends to not be transparent for the reader. The objective of this paper is to study this problem and describe in detail the process of creating a questionnaire based on the MTSK model, in order to explore the teacher's knowledge of parabolas, understood as conic sections. We present the design of a qualitative instrument that allows for the approximation of the teacher's mathematical knowledge of parabolas, emphasizing on the use of theory, as well as both internal and external triangulation, as key elements in the methodological design. The main contribution of this paper is to give guidelines for the design of questionnaires based on the MTSK model, which can be taken into account regardless of the mathematical contents.La investigación en Educación Matemática suele centrarse en compartir los resultados de la aplicación de instrumentos de obtención de información. Si bien dichos instrumentos suelen describirse en la sección de metodología, el proceso de su desarrollo no suele ser muy transparente para el lector. En esta investigación el objetivo es abordar dicha problemática y describir con todo detalle el proceso de generación de un cuestionario, basado en el modelo MTSK, para la exploración del conocimiento del profesor acerca de la parábola, entendida como cónica. Se presenta el diseño de un instrumento de carácter cualitativo que permite hacer una aproximación al conocimiento matemático del profesor acerca de la parábola, poniendo énfasis tanto en el uso de la teoría, como de la triangulación, interna y externa, como elementos clave en el diseño metodológico. El principal aporte fue determinar pautas para el diseño de cuestionarios basados en el modelo MTSK, las cuales pueden ser tomadas en cuenta al margen de los contenidos matemáticos.A pesquisa na Educação Matemática tende a estar centrada no compartilhamento dos resultados da aplicação de instrumentos de alcance de informação. Embora tais instrumentos se inclinem a estar descritos na seção de metodologia, o processo de seu desenvolvimento tende a não ser muito transparente para o leitor. Nesta pesquisa o objetivo é abordar essa problemática e descrever detalhadamente o processo de criação de um questionário, com base no modelo MTSK, para a exploração do conhecimento do professor sobre a parábola, entendida como cônica. É apresentado o desenho de um instrumento de carácter qualitativo, que permite fazer uma aproximação ao conhecimento matemático do professor sobre a parábola, colocando ênfase tanto no uso da teoria quanto da triangulação, interna e externa, como elementos-chave no desenho metodológico. A principal contribuição foi determinar pautas para o desenho de questionários baseados no modelo MTSK, que podem ser levadas em consideração independentemente dos conteúdos matemáticos