Unsaturated phosphonic acid, a novel precursor to fabricate metal organic frameworks

Investigations on phosphonates metal organic frameworks (MOFs) have attracted interest during the last two decades due to their captivating network topology, structural flexibility and multiple special properties. The synthesis of 1 -phenylphosphonium acid, as precursor of metal organic framework was described. The synthesized compound was analyzed by 'H and 31P-NMR, HPLC, MS, TG and IR spectroscopy. The PM3 semi-empirical analysis of precursor was made in order to establish their design, structural properties, thermodynamic and electronic properties

Synthesis and characterization of a new metal organic framework

The synthesis of a new metal-phosphonate is described in this paper. Mg2+ vinylphosphonate has been synthesized by using an equimolecular ratio of reagents in hydrothermal conditions. The compound has been characterized by X-Ray and IR spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermo gravimetry (TG) and quantum chemical calculations. Last method have been used to establish supramolecular pores size and to predict synthesized compound ability to filter hydrogen, methane, carbon dioxide, carbon monoxide, sulphur dioxide and benzene gases

Structure simulation into a lamellar supramolecular network and calculation of the metal ions/ligands ratio

BACKGROUND: Research interest in phosphonates metal organic frameworks (MOF) has increased extremely in the last two decades, because of theirs fascinating and complex topology and structural flexibility. In this paper we present a mathematical model for ligand/metal ion ratio of an octahedral (O(h)) network of cobalt vinylphosphonate (Co(vP)·H(2)O). RESULTS: A recurrent relationship of the ratio between the number of ligands and the number of metal ions in a lamellar octahedral (O(h)) network Co(vP)·H(2)O, has been deducted by building the 3D network step by step using HyperChem 7.52 package. The mathematical relationship has been validated using X ray analysis, experimental thermogravimetric and elemental analysis data. CONCLUSIONS: Based on deducted recurrence relationship, we can conclude prior to perform X ray analysis, that in the case of a thermogravimetric analysis pointing a ratio between the number of metal ions and ligands number around 1, the 3D network will have a central metal ion that corresponds to a single ligand. This relation is valid for every type of supramolecular network with divalent metal central ion O(h) coordinated and bring valuable information with low effort and cost

Chitosan for fungal diseases control

The use of chitosan is a promising alternative; it can be applied in many fields based on its biological activity and easy-to-obtain procedures. Such it was used in agriculture, environmental protection, pharmaceutical and biomedical applications. The fungicidal activity of the chitosan against Fusarium graminearum, Penicillium chrysogenum and Aspergillus orizae were done by using the plate growth rate method

Cobalt phosphinates as precursors of cobalt phosphide electrocatalysts

https://qies22.icms.us-csic.es/The scarcity and high cost of Pt and Ru/Ir-based noble metal electrocatalysts forces to design alternative low-cost and efficient materials for sustainable energy storage and conversion technologies. Among them, phosphorus-containing coordination polymers, such as phosphinates, have emerged as potential precursors of transition-metal phosphide (TMP) electrocatalysts. The possibility of incorporating two funtionalized organic moieties into the phosphinate ligands makes metal phosphinates highly attractive precursors to obtain core-shell carbon/TMP electrocatalysts. In this research-work, we report the synthesis and crystal structure of two Co2+-phosphinates derived from the (2-carboxyethyl)(phenyl)phosphinic acid (CEPPA), Co2[(O2P(CH2CH2COO)(C6H5)(H2O)]2·2H2O (CoCEPPA-1D) and Co3[O2P(CH2CH2COO)(C6H5)]2(OH)2 (CoCEPPA-2D), synthesized by microwave-assisted method. These solids were used as precursor of cobalt phosphides (Co2P/CoP) by thermal reduction under 5%H2-Ar atmosphere at different temperatures and their electrocatalytic performances were investigated toward Oxygen Evolution Reaction (OER), Oxygen Reduction Reaction (ORR) and Hydrogen Evolution Reaction (HER). The relationship between Co/P molar ratios and/or the Co2+ coordination environment in the precursor structures and the electrocatalytic activity of the prepared cobalt phosphides will be discussed.Proyectos de investigación PID2019-110249RB-I00 (MICIU/AEI, Ministerio de España) y PY20-00416 (Junta de Andalucia, Spain/FEDER). Ayudas para Doctores PAIDI2020 (DOC_00272 Junta de Andalucia, España) y Plan Propio de Investigación de la Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

T A I L O R E D ST A R -SHAPE B I O D E G R A D A B L E P O L Y ( L A C T I C A C I D )

S e r i e s o f C h e m i s t r y 1 9 ( 4 ) ( 2 0 1 0 ) 1 9 -26 T A I L O R E D ST A R -SHAPE B I O D E G R A D A B L E P O L Y ( L A C T I C A C I D ) G. polycondensation method, using as catalyst tin chloride, and phosphorus oxychloride or 2-amino-2-methyl-1,3-propandiol as core. The influence of molar ration and concentration of catalyst on molar masses was studied. Moderately high molecular weight and inherent viscosities values up to 0.60 dl/g were obtained

Imidazole-containing Co2+ and Ni2+ etidronates: crystal structures and electrochemical behaviour

Proyecto Nacional PID2019-110249RB-I00, PAIDI2020 de la Junta de Andalucia, Ayudas del Plan Propio de Investigación de la Universidad de Málaga para la contratación predoctoral (PRE2020-094459).Metal phosphonates-based coordination polymers (CPs) are known to exhibit versatile structural diversity and functionality. Thus, they have been used, among other applications, as electrocatalyst precursors for both, PEMFCs and electrolysers. In this work, we report the synthesis, crystal structure and electrochemical properties of imidazole-containing Co2+, Ni2+ and Zn2+ derivatives of the etidronic acid, (HO)2P(O)-C(CH3)(OH)-P(O)(OH)2 (ETID). Analyses of the crystal structures reveals that these solids are 1D, in which the imidazole molecules form part of the coordination sphere of the cations (Co2+, Ni2+) or act as charge-compensating imidazolium cations (Zn2+). Co2+ and Ni2+ solids were pyrolysed under 5% H2/Ar atmosphere at different temperatures. The resulting metal phosphides were tested as electrocatalysts for the Oxygen Evolution and Reduction Reactions (OER and ORR, respectively) and the Hydrogen Evolution Reaction (HER). Preliminary results indicate that Co2+ derivatives exhibit better performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Exploiting the Multifunctionality of M2+/Imidazole−Etidronates for Proton Conductivity (Zn2+) and Electrocatalysis (Co2+, Ni2+) toward the HER, OER, and ORR

This work deals with the synthesis and characterization of one-dimensional (1D) imidazole-containing etidronates, [M2(ETID)(Im)3]·nH2O (M = Co2+ and Ni2+; n = 0, 1, 3) and Zn2(ETID)2(H2O)2](Im)2, as well as the corresponding Co2+/Ni2+ solid solutions. Depending on the water content, metal ions in the isostructural Co2+ and Ni2+ derivatives are octahedrally coordinated (n = 3) or consist of octahedral together with dimeric trigonal bipyramidal (n = 1) or square pyramidal (n = 0) environments. The imidazole molecule acts as a ligand (Co2+, Ni2+ derivatives) or charge-compensating protonated species (Zn2+ derivative). For the latter, the proton conductivity is determined to be ∼6 × 10−4 S·cm−1 at 80 °C and 95% relative humidity (RH). By pyrolyzing in 5%H2−Ar at 700−850 °C, core−shell electrocatalysts consisting of Co2+-, Ni2+-phosphides or Co2+/Ni2+-phosphide solid solution particles embedded in a N-doped carbon graphitic matrix are obtained, which exhibit improved catalytic performances compared to the non-N-doped carbon materials. Co2+ phosphides consist of CoP and Co2P in variable proportions according to the used precursor and pyrolytic conditions. However, the Ni2+ phosphide is composed of Ni2P exclusively at high temperatures. Exploration of the electrochemical activity of these metal phosphides toward the OER, ORR, and HER reactions reveals that the anhydrous Co2(ETID)(Im)3 pyrolyzed at 800 °C (CoP/Co2P = 80/20 wt %) is the most active trifunctional electrocatalyst, with good integrated capabilities as an anode for overall water splitting (cell voltage of 1.61 V) and potential application in Zn−air batteries. This solid also displays a moderate activity for the HER with an overpotential of 156 mV and a Tafel slope of 79.7 mV·dec−1 in 0.5 M H2SO4. Ni2+- and Co2+/Ni2+-phosphide solid solutions show lower electrochemical performances, which are correlated with the formation of less active crystalline phases.The work at UMA was funded by PID2019-110249RB-I00 (MICIU/AEI, Spain) and PY20-00416 (Junta de Andalucia, Spain/FEDER) research projects. A.V.-C. thanks MICIU for PRE2020-094459 student grant; M.B.-G. thanks PAIDI2020-DOC_00272 research grant (Junta de Andalucia, Spain) and R.M.P.C. thanks University of Malaga under Plan Propio de Investigación for financial support. Funding for open access charge: Universidad de Málaga/CBUA (PMCID# PMC8915163

Synthesis and structural characterization of 2-D layered copper(II) styrylphosphonate coordination polymers

We report the synthesis, physicochemical characterization, and crystal structure of Cu-SP (SP = styrylphosphonic acid, H2O3PCH=CH2(C6H5)), the first reported example of a metal derivative of SP. The starting SP acid was fully characterized by X-ray single-crystal diffractometry, elemental analysis (C and H), 31P-NMR, 13C-NMR, 1H-NMR, HPLC, UV–vis, MS, TG, and FT-IR spectroscopy. The copper(II) derivative was synthesized and characterized by DTA-TG and FT-IR, and also its structure was determined from powder data. The crystal structure was refined by the Rietveld method. The crystal structure of Cu-SP shows a layered 2-D architecture, where the organic moieties are pointed toward the interlamellar space. The inorganic layers are composed of Cu2+ dimers, where the coordination geometry of Cu2+ can be described as distorted trigonal bipyramid. The three coplanar oxygens (O2, O3, and O3) have bond distances of 2.165(9), 1.982(9), and 2.103(11) Å, respectively. The bond lengths for the apical oxygens (O1 and O2) are 1.908(13) and 1.996(11) Å, respectively.Proyecto nacional MAT2010-1517

Synthesis and Electrochemical properties of metal(II)- carboxyethylphenylphosphinates

https://doi.org/10.1039/D1DT00104CWe report herein the synthesis, structural characterization and electrocatalytic properties of three new coordination polymers, resulting from the combination of divalent metal (Ca2+, Cd2+ or Co2+) salts with (2-carboxyethyl)(phenyl)phosphinic acid. In addition to the usual hydrothermal procedure, the Co2+ derivative could be also prepared by microwave-assisted synthesis, in much shorter times. The crystal structures were solved ab initio, from powder diffraction data. Compounds MII[O2P(CH2CH2COOH)(C6H5)]2 {M= Cd (1) or Ca (2)} crystallize in the monoclinic system and display a layered topology, with the phenyl groups pointing toward the interlayer space in a interdigitated fashion. Compound Co2[(O2P(CH2CH2COO)(C6H5)(H2O)]2·2H2O (3) presents a 1D structure composed of zig-zag chains, formed by edge-sharing cobalt octahedra, with phenyl groups pointing outside. Packing of these chains is favored by hydrogen bond interactions via lattice water. In addition, H-bonds along the chains are established with participation of the water molecules and the hydrophilic groups from the ligand. However, the solid exhibits a low proton conductivity, attributed to the isolation of the hydrophilic regions caused by the arrangement of hydrophobic phenyl groups. Preliminary studies on the electrocatalytical performance for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have been conducted for compound 3 and its pyrolytic derivatives, which were previously throughout characterized. By comparison, another Co2+ phosphinate, 4, obtained by microwave-assisted synthesis, but with distinct stoichiometry and known structure was also tested. For OER, the best performance was reached with a derivative of 3, prepared by heating this compound in N2 at 200 °C. This derivative presented overpotential (339 mV, for a current density of 10 mA·cm-2) and Tafel slope (51.7 mV·dec-1) values comparable to other Co2+ related materials.Proyecto nacional del MICINN MAT2016-77648-R; PID2019-110249RB-I00 y FQM-113 proyectos de la Junta de Andalucía. Plan Propio de la UMA y ALBA Sincrotrón por la utilización de la línea BM04 beam-line en el experimento (proposal nº 2016091873