19 research outputs found
Synthesis, crystal structures, Hirshfeld surface analysis and physico-chemical characterization of two new ZnII and CdII halidometallates
Two new organic鈥搃norganic hybrid materials, based on 1, 3-CycloHexaneBis-(Methyl Amine), abbreviated CHBMA, namely (H2CHBMA)ZnCl4路2H2O (CP1) and (H2CHBMA)CdI4路2H2O (CP2), have been synthesized under mild conditions in acidic media and characterized by single-crystal X-ray diffraction, spectroscopic techniques (13C NMR, FTIR, RAMAN) and thermal analysis. The crystal structures of the two compounds were solved by single-crystal X-ray diffraction methods. Both compounds show a 3-dimensional supramolecular structure directed by various interactions between tetrahalidometallate anions (ZnCl42-, CdI42-), water molecule and organic cations (H2CHBMA)2+. For both compounds, the cyclohexane ring of the template cation is in a chair conformation with the methylammonium substituent in the equatorial positions and the two terminal ammonium groups in a cis conformation but with two different orientations (upward for CP1 and downward for CP2) which influences the supramolecular architecture of the two structures. Hirshfeld surface analysis and the associated two-dimensional finger print plots were used to explore and quantify the intermolecular interactions in the crystals
Single-crystal-to-single-crystal transformation and catalytic properties of new hybrid perhalidometallates
Two new organic鈥搃norganic salts of perhalidometallates with protonated organic amine cations have been synthesized and characterized by X-ray diffraction and thermal analysis. (CHBMAH2) ZnBr4路3/2H2O 1 and (CHBMAH2 )ZnCl4 4 [(CHBMAH2 )2+: 1, 3-cyclohexanebis(methylammonium)] were obtained in single-crystal form. The crystal packing in all of the obtained compounds is governed by the formation of various non-covalent intermolecular forces between tetrahalidometallate anions and organic cations, assisted by water molecules in the hydrates. Hirshfeld surface analysis denotes that the most important contributions to the crystal packing are X路路路H/H路路路X (X: Cl, Br, I) and H路路路H interactions. Interestingly, the compound 1, 3-cyclohexanebis(methylammonium)tetrachlorido-zincate (II) dihydrate, (CHBMAH2 )ZnCl4路2H2O 2, undergoes thermally-triggered single-crystal-to-single-crystal (SCSC) transformation upon dehydration to produce a supramolecular solid compound, 1, 3-cyclohexanebis(methylammonium) tetrachloridozincate (II), (CHBMAH2 )ZnCl4 4. The SCSC transformation causes changes in the lattice parameters and a structural rearrangement. Furthermore, the catalytic properties of (CHBMAH2 )ZnCl4路2H2O 2 and (CHBMAH2 )CdI4路2H2O 3 have been explored in the acetalization process using various uncommon alcohols, beyond methanol or ethanol, for the first time in the literature, with outstanding results, and opening the door to the formation of alternative acetals. 漏 2021 by the authors. Licensee MDPI, Basel, Switzerland
Research of the origin of a particular Tunisian group using a physical marker and Alu insertion polymorphisms
The aim of this study was to show how, in some particular circumstances, a physical marker can be used along with molecular markers in the research of an ancient people movement. A set of five Alu insertions was analysed in 42 subjects from a particular Tunisian group (El Hamma) that has, unlike most of the Tunisian population, a very dark skin, similar to that of sub-Saharans, and in 114 Tunisian subjects (Gabes sample) from the same governorate, but outside the group. Our results showed that the El Hamma group is genetically midway between sub-Saharan populations and North Africans, whereas the Gabes sample is clustered among North Africans. In addition, The A25 Alu insertion, considered characteristic to sub-Saharan Africans, was present in the El Hamma group at a relatively high frequency. This frequency was similar to that found in sub-Saharans from Nigeria, but significantly different from those found in the Gabes sample and in other North African populations. Our molecular results, consistent with the skin color status, suggest a sub-Saharan origin of this particular Tunisian group
A Decision Support System for Optimal Use of Irrigation Water and Crop Selection
We propose a Decision Support System (DSS) for optimal cropping patterns and irrigation water management. The development of the DSS has three objectives. The first is to use mathematical models in order to optimize cropping decisions and irrigation policies under shortage of water in the Kingdom of Saudi Arabia. The second is to help growers exploit optimally their lands in places suffering from water scarcity. The third is to provide authorities with decision tools for water pricing and allocation. The optimization models are designed to determine which ones among competing crops to select for a given season/year, and how much land and irrigation water to allocate to each selected crop. In particular, some crops may be deliberately under irrigated to save water and hence to maximize the total area to be irrigated. The computer package estimates the expected yield of each of the competing crops in each irrigation level to be considered. Then, it implements the optimization models to provide the optimal cropping decisions as well as the corresponding irrigation policies. While the package is very sophisticated, its implementation is very simple and practical. Keywords:: Linear programming, Dynamic programming, Cropping patterns, Irrigation management, Decision support system
Single-crystal-to-single-crystal transformation and catalytic properties of new hybrid perhalidometallates
This article belongs to the Special Issue Catalytic Approaches to Selective Elaboration of Organic Molecules.Two new organic鈥搃norganic salts of perhalidometallates with protonated organic amine cations have been synthesized and characterized by X-ray diffraction and thermal analysis. (CHBMAH2)ZnBr4路3/2H2O 1 and (CHBMAH2)ZnCl4 4 [(CHBMAH2)2+: 1,3-cyclohexanebis(methylammonium)] were obtained in single-crystal form. The crystal packing in all of the obtained compounds is governed by the formation of various non-covalent intermolecular forces between tetrahalidometallate anions and organic cations, assisted by water molecules in the hydrates. Hirshfeld surface analysis denotes that the most important contributions to the crystal packing are X路路路H/H路路路X (X: Cl, Br, I) and H路路路H interactions. Interestingly, the compound 1,3-cyclohexanebis(methylammonium)tetrachloridozincate (II) dihydrate, (CHBMAH2)ZnCl4路2H2O 2, undergoes thermally-triggered single-crystal-to-single-crystal (SCSC) transformation upon dehydration to produce a supramolecular solid compound, 1,3-cyclohexanebis(methylammonium) tetrachloridozincate (II), (CHBMAH2)ZnCl4 4. The SCSC transformation causes changes in the lattice parameters and a structural rearrangement. Furthermore, the catalytic properties of (CHBMAH2)ZnCl4路2H2O 2 and (CHBMAH2)CdI4路2H2O 3 have been explored in the acetalization process using various uncommon alcohols, beyond methanol or ethanol, for the first time in the literature, with outstanding results, and opening the door to the formation of alternative acetals.This research was funded by Agencia Estatal de Investigaci贸n (AEI), projects CTQ2017-88091-P, PID2019-104379RB-C21, PID2020-117455GB-I00 and PGC2018-093451-B-I00 and Gobierno de Arag贸n-Fondo Social Europeo (Research Groups E07_20R and E17_17R).Peer reviewe
Propiedades catal铆ticas de nuevos perhalidometalatos h铆bridos
Resumen del p贸ster presentado a la 9陋 Jornada de J贸venes Investigadores de Qu铆mica y F铆sica de Arag贸n, celebrada el 16 de diciembre de 2021 en la Universidad de Zaragoza.Peer reviewe
Decision support system for optimal use of irrigation water and crop selection
We propose a decision support system (DSS) for formal cropping patterns and irrigation water management. The development of the DSS has three objectives. The first is to use mathematical model in order to optimize cropping decisions and irrigation policies under storage of water in the Kingdom Of Saudi Arabia. The second is to help growers exploit optimally their lands in places suffering from water scarcity. The third is to provide authorities with decision tools of water pricing all location. The optimization model are designed to determine which ones among competing crops may be deliberately under irrigated to save water and hence to maximize the the total area to be irrigated. The computer package estimates the expected yield of each of the computing crops in each irrigation level to be considered. Then, it implements the optimization models to provide the optimal cropping decisions as well as the corresponding irrigation policies. While the package is very sophisticated, its implementation is very simple and practical
Catalytic properties of new hybrid perhalidometallates
Resumen del p贸ster presentado a la XXIV Virtual Conference of Organometallic Chemistry (EuCOMC XXIV), celebrada del 1 al 3 de septiembre de 2021.Peer reviewe