Supramolecular and functionnal architectures : towards efficient magnets / Bretosh, Kateryna  

Public ISBD Titre : Supramolecular and functionnal architectures : towards efficient magnets Type de document : texte imprimé Auteurs : Bretosh, Kateryna, Auteur ; Jean-Pascal Sutter, Directeur de thèse ; Béreau, Virginie, Directeur de thèse Année de publication : 2019 Langues : Anglais (eng) Tags : FE(II) - NI(II) - MAGNETIC ANISOTROPY - SCM - SMM - HEPTACOORDINATE - MOLECULAR MAGNETISM Résumé : "This thesis deals with the control of magnetic anisotropy in the design of molecule-based magnetic materials. Magnetic anisotropy is highly related to the coordination environment of a metal ion. Herein we focused on 3d metal ions with pentagonal bipyramid coordination spheres that may exhibit a rather large magnetic anisotropy. A series of seven coordinate Fe(II) and Ni(II) complexes formed with a neutral pentadentate cyclic ligand (LN5PhenMe) were synthesized and their magnetic behaviors investigated. They have been found to exhibit axial (Ising-type) magnetic anisotropy with a negative zero-field splitting axial parameter D. Modulation of magnetic anisotropy was studied for Fe(II) complexes with various substituents in axial position (Fe(II)LN5PhenMeX2, where X= Cl-, Br- , I-, NCS-, ROH, {Ni(CN)4}2-) revealing D values spanning from ca -4 to -17 cm-1. Due to the large axial anisotropy induced by heavier halogen atoms in Br and I derivatives, these complexes showed SMM (Single Molecular Magnet) properties with energy barrier Ueff/kB ~ 70 K. These complexes are structurally robust and can be used as building units to form polynuclear systems. Their combination with a related trans-cyano K[CrLN3O2Ph(CN)2] complex allowed the synthesis of trinuclear complexes [{CrLN3O2Ph(CN)2}2MLN5PhenMe] (M= Fe(II) or Ni(II)), and a 1-D coordination polymer [{CrLN3O2Ph(CN)2}MLN5PhenMe][ClO4]n showing respectively, SMM and SCM (Single Chain Magnets) behaviors. The latter is the first example of SCM made with pentagonal bipyramid Ni centers." Document : Thèse de Doctorat Etablissement_delivrance : Université de Toulouse 3 Date_soutenance : 29/10/2019 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie Organométallique et de Coordination Localisation : LCC En ligne : http://thesesups.ups-tlse.fr/4681/ Supramolecular and functionnal architectures : towards efficient magnets [texte imprimé] / Bretosh, Kateryna, Auteur ; Jean-Pascal Sutter, Directeur de thèse ; Béreau, Virginie, Directeur de thèse . - 2019. Langues : Anglais (eng) Tags : FE(II) - NI(II) - MAGNETIC ANISOTROPY - SCM - SMM - HEPTACOORDINATE - MOLECULAR MAGNETISM Résumé : "This thesis deals with the control of magnetic anisotropy in the design of molecule-based magnetic materials. Magnetic anisotropy is highly related to the coordination environment of a metal ion. Herein we focused on 3d metal ions with pentagonal bipyramid coordination spheres that may exhibit a rather large magnetic anisotropy. A series of seven coordinate Fe(II) and Ni(II) complexes formed with a neutral pentadentate cyclic ligand (LN5PhenMe) were synthesized and their magnetic behaviors investigated. They have been found to exhibit axial (Ising-type) magnetic anisotropy with a negative zero-field splitting axial parameter D. Modulation of magnetic anisotropy was studied for Fe(II) complexes with various substituents in axial position (Fe(II)LN5PhenMeX2, where X= Cl-, Br- , I-, NCS-, ROH, {Ni(CN)4}2-) revealing D values spanning from ca -4 to -17 cm-1. Due to the large axial anisotropy induced by heavier halogen atoms in Br and I derivatives, these complexes showed SMM (Single Molecular Magnet) properties with energy barrier Ueff/kB ~ 70 K. These complexes are structurally robust and can be used as building units to form polynuclear systems. Their combination with a related trans-cyano K[CrLN3O2Ph(CN)2] complex allowed the synthesis of trinuclear complexes [{CrLN3O2Ph(CN)2}2MLN5PhenMe] (M= Fe(II) or Ni(II)), and a 1-D coordination polymer [{CrLN3O2Ph(CN)2}MLN5PhenMe][ClO4]n showing respectively, SMM and SCM (Single Chain Magnets) behaviors. The latter is the first example of SCM made with pentagonal bipyramid Ni centers." Document : Thèse de Doctorat Etablissement_delivrance : Université de Toulouse 3 Date_soutenance : 29/10/2019 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie Organométallique et de Coordination Localisation : LCC En ligne : http://thesesups.ups-tlse.fr/4681/

[M(NCS)6]3(2)- (M=MoIII,ReIV) as building units in molecular magnetism / Mousavi Sangdehi, Maliheh Sadat  

Public ISBD Titre : [M(NCS)6]3(2)- (M=MoIII,ReIV) as building units in molecular magnetism Type de document : texte imprimé Auteurs : Mousavi Sangdehi, Maliheh Sadat, Auteur ; Jean-Pascal Sutter, Directeur de thèse ; Béreau, Virginie, Directeur de thèse Année de publication : 2011 Langues : Anglais (eng) Tags : MOLECULAR MAGNETISM  THIOCYANO  EXCHANGE INTERACTION  MO(III)  RE(IV)  HETERONUCLEAR  DFT CALCULATIONS  MOLECULAR MATERIALS Résumé : "This thesis concerns the field of molecular magnetic materials. Our goal was to investigate the potential of the {M(NCQ)6}3-, (M = MoIII, ReIV; Q = S, Se) anionic complexes for the preparation of thiocyanato-bridged {3d-4(5)d} heterometallic compounds with efficient exchange couplings. Spin density distributions obtained from DFT calculations on {Mo(NCS)6}3-, {Mo(NCSe)6}3-, {Re(NCS)6}2- show that the magnetic information is efficiently transferred from the metal to the ligands. Experimental insights into the magnetic communication mediated by NCS between MoIII and either Co, Ni have been deduced from the magnetic behavior of a series of isomorphic compounds of formula {[M(NCQ}6{M'LN4}2(NCS)] (M = CrIII, MoIII; M' = NiII, CoII ; Q = S, Se). The magnetic studies and their analysis show that Mo-NCS-Ni interaction is strong (JMoNi/Co = -50 cm-1) and twice Cr-Ni interaction. Because S atom can bind preferentially soft metal ions, we have used this property to obtain the mixed valence coordination polymer [{Mo(NCS}6{NiIILN4}]8{CoIIILN4Br2} and the related heterotrimetallic derivative [{Mo(NCS}6{NiIILN4}]8{CoIIILN4Br2}. We also describe a bidimensional system {Mo2Co3} which behaves as a ferri-magnet with TC = 40 K. Two examples of hetero-metallic architectures Mo-Cu are presented and finally, in the last part of this manuscript, the formation of polymetallic aggregates between Ni or Cu-Schiff bases complexes and potassium salts are described." Document : Thèse de Doctorat Etablissement_delivrance : Université de Toulouse 3 Date_soutenance : 08/12/2011 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie organométallique et de coordination Localisation : LCC En ligne : http://thesesups.ups-tlse.fr/1718/ [M(NCS)6]3(2)- (M=MoIII,ReIV) as building units in molecular magnetism [texte imprimé] / Mousavi Sangdehi, Maliheh Sadat, Auteur ; Jean-Pascal Sutter, Directeur de thèse ; Béreau, Virginie, Directeur de thèse . - 2011. Langues : Anglais (eng) Tags : MOLECULAR MAGNETISM  THIOCYANO  EXCHANGE INTERACTION  MO(III)  RE(IV)  HETERONUCLEAR  DFT CALCULATIONS  MOLECULAR MATERIALS Résumé : "This thesis concerns the field of molecular magnetic materials. Our goal was to investigate the potential of the {M(NCQ)6}3-, (M = MoIII, ReIV; Q = S, Se) anionic complexes for the preparation of thiocyanato-bridged {3d-4(5)d} heterometallic compounds with efficient exchange couplings. Spin density distributions obtained from DFT calculations on {Mo(NCS)6}3-, {Mo(NCSe)6}3-, {Re(NCS)6}2- show that the magnetic information is efficiently transferred from the metal to the ligands. Experimental insights into the magnetic communication mediated by NCS between MoIII and either Co, Ni have been deduced from the magnetic behavior of a series of isomorphic compounds of formula {[M(NCQ}6{M'LN4}2(NCS)] (M = CrIII, MoIII; M' = NiII, CoII ; Q = S, Se). The magnetic studies and their analysis show that Mo-NCS-Ni interaction is strong (JMoNi/Co = -50 cm-1) and twice Cr-Ni interaction. Because S atom can bind preferentially soft metal ions, we have used this property to obtain the mixed valence coordination polymer [{Mo(NCS}6{NiIILN4}]8{CoIIILN4Br2} and the related heterotrimetallic derivative [{Mo(NCS}6{NiIILN4}]8{CoIIILN4Br2}. We also describe a bidimensional system {Mo2Co3} which behaves as a ferri-magnet with TC = 40 K. Two examples of hetero-metallic architectures Mo-Cu are presented and finally, in the last part of this manuscript, the formation of polymetallic aggregates between Ni or Cu-Schiff bases complexes and potassium salts are described." Document : Thèse de Doctorat Etablissement_delivrance : Université de Toulouse 3 Date_soutenance : 08/12/2011 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie organométallique et de coordination Localisation : LCC En ligne : http://thesesups.ups-tlse.fr/1718/

---

1 (1 - 2 / 2) Par page : 25 50 100 200