Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both compounds have been investigated down to 2 K. The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K

Functional ligand designs for the elaboration of magnetic networks based on iron, cobalt or rare earth ions

L’objectif de cette thèse porte sur la conception de nouveaux composés de coordination à partir de ligands imidazolium fonctionnalisés par différentes fonctions de coordination ou de ligands dérivés du motif 1,2,4-triazole et de cations de transition tels que les ions Fe2+ ou Co2+ ou d’ions lanthanides tels que les ions Dy3+. Le but de ces associations est de générer des réseaux fonctionnels pouvant présenter des propriétés magnétiques voire de luminescence. Plusieurs méthodes de synthèse ont été utilisées pour obtenir ces composés : méthode solvothermale, méthode de diffusion ou encore modification post-synthèse lorsque les méthodes directes ne marchaient pas. La mise en oeuvre de ces différentes méthodologies a permis d’obtenir plusieurs composés qui ont été caractérisés structuralement, spectrocopiquement et magnétiquement en exploitant différentes techniques telles que la diffraction de rayons X, la spectroscopie infrarouge et UV-Visible, la microscopie électronique à balayage, les analyses thermiques et élémentaires ou encore la spectroscopie de photoélectrons et la magnétométrie à SQUID.The aim of this thesis is to progress in the design of new coordination networks using imidazolium ligands functionalized with different coordination functions or ligands based on 1,2,4-triazole and transition metals such as Fe2+ or Co2+ or lanthanide ions such as Dy3+. The goal is to generate magnetic and even luminescent networks. Several synthesis strategies have been used to obtain these compounds : solvothermal and non-solvothermal reactions and post-synthesis modifications when direct reactions were not efficient. The use of these strategies has led to several compounds for which structural characterization have been performed using X ray diffraction. Analysis such as infrared and UV-Visible spectroscopies, scanning electronic microscope, thermal and elementary analysis end even X-ray photoelectron spectroscopy as well as SQUID magnetometry have been carried out to fully characterized all these compounds

Functional ligand designs for the elaboration of magnetic networks based on iron, cobalt or rare earth ions

L’objectif de cette thèse porte sur la conception de nouveaux composés de coordination à partir de ligands imidazolium fonctionnalisés par différentes fonctions de coordination ou de ligands dérivés du motif 1,2,4-triazole et de cations de transition tels que les ions Fe2+ ou Co2+ ou d’ions lanthanides tels que les ions Dy3+. Le but de ces associations est de générer des réseaux fonctionnels pouvant présenter des propriétés magnétiques voire de luminescence. Plusieurs méthodes de synthèse ont été utilisées pour obtenir ces composés : méthode solvothermale, méthode de diffusion ou encore modification post-synthèse lorsque les méthodes directes ne marchaient pas. La mise en oeuvre de ces différentes méthodologies a permis d’obtenir plusieurs composés qui ont été caractérisés structuralement, spectrocopiquement et magnétiquement en exploitant différentes techniques telles que la diffraction de rayons X, la spectroscopie infrarouge et UV-Visible, la microscopie électronique à balayage, les analyses thermiques et élémentaires ou encore la spectroscopie de photoélectrons et la magnétométrie à SQUID.The aim of this thesis is to progress in the design of new coordination networks using imidazolium ligands functionalized with different coordination functions or ligands based on 1,2,4-triazole and transition metals such as Fe2+ or Co2+ or lanthanide ions such as Dy3+. The goal is to generate magnetic and even luminescent networks. Several synthesis strategies have been used to obtain these compounds : solvothermal and non-solvothermal reactions and post-synthesis modifications when direct reactions were not efficient. The use of these strategies has led to several compounds for which structural characterization have been performed using X ray diffraction. Analysis such as infrared and UV-Visible spectroscopies, scanning electronic microscope, thermal and elementary analysis end even X-ray photoelectron spectroscopy as well as SQUID magnetometry have been carried out to fully characterized all these compounds

Conception de ligands fonctionnels pour l'élaboration de réseaux magnétiques à base d'ions du fer, du cobalt ou de terre rare

The aim of this thesis is to progress in the design of new coordination networks using imidazolium ligands functionalized with different coordination functions or ligands based on 1,2,4-triazole and transition metals such as Fe2+ or Co2+ or lanthanide ions such as Dy3+. The goal is to generate magnetic and even luminescent networks. Several synthesis strategies have been used to obtain these compounds : solvothermal and non-solvothermal reactions and post-synthesis modifications when direct reactions were not efficient. The use of these strategies has led to several compounds for which structural characterization have been performed using X ray diffraction. Analysis such as infrared and UV-Visible spectroscopies, scanning electronic microscope, thermal and elementary analysis end even X-ray photoelectron spectroscopy as well as SQUID magnetometry have been carried out to fully characterized all these compounds.L’objectif de cette thèse porte sur la conception de nouveaux composés de coordination à partir de ligands imidazolium fonctionnalisés par différentes fonctions de coordination ou de ligands dérivés du motif 1,2,4-triazole et de cations de transition tels que les ions Fe2+ ou Co2+ ou d’ions lanthanides tels que les ions Dy3+. Le but de ces associations est de générer des réseaux fonctionnels pouvant présenter des propriétés magnétiques voire de luminescence. Plusieurs méthodes de synthèse ont été utilisées pour obtenir ces composés : méthode solvothermale, méthode de diffusion ou encore modification post-synthèse lorsque les méthodes directes ne marchaient pas. La mise en oeuvre de ces différentes méthodologies a permis d’obtenir plusieurs composés qui ont été caractérisés structuralement, spectrocopiquement et magnétiquement en exploitant différentes techniques telles que la diffraction de rayons X, la spectroscopie infrarouge et UV-Visible, la microscopie électronique à balayage, les analyses thermiques et élémentaires ou encore la spectroscopie de photoélectrons et la magnétométrie à SQUID

Octahedral Hexachloro Environment of Dy3+ with Slow Magnetic Relaxation and Luminescent Properties

International audienceThe compound [BiCNIm]3[DyCl6] was synthesized from a nitrile-functionalized imidazolium ionic liquid [BiCNIm][Cl] and DyCl3 ⋅ 6H2O in acetonitrile using solvothermal conditions. Structural characterization reveals that the Dy3+ ions are in a quasi-regular octahedral environment, formed by six chloride anions. The magnetic study indicates that this mononuclear compound exhibits a Single Ion Magnet behaviour. This behaviour is compared to that of other mononuclear compounds containing Dy3+ ions in various octahedral environment

Abstracts of 1st International Conference on Computational & Applied Physics

This book contains the abstracts of the papers presented at the International Conference on Computational & Applied Physics (ICCAP’2021) Organized by the Surfaces, Interfaces and Thin Films Laboratory (LASICOM), Department of Physics, Faculty of Science, University Saad Dahleb Blida 1, Algeria, held on 26–28 September 2021. The Conference had a variety of Plenary Lectures, Oral sessions, and E-Poster Presentations. Conference Title: 1st International Conference on Computational & Applied PhysicsConference Acronym: ICCAP’2021Conference Date: 26–28 September 2021Conference Location: Online (Virtual Conference)Conference Organizer: Surfaces, Interfaces, and Thin Films Laboratory (LASICOM), Department of Physics, Faculty of Science, University Saad Dahleb Blida 1, Algeria