Anilate-based Molecular Building Blocks for Metal-Organic Frameworks and Molecular Conductors

This work reports on the design, synthesis and characterization of novel anilate-based functional molecular materials showing luminescent, magnetic and/or conducting properties. The family of anilate ligands comprises several derivatives obtained by introducing various substituents (H, F, Cl, Br, I, CN, etc.) at the 3 and 6 positions of the common 2,5-dihydroxy-1,4-benzoquinone framework. Their electronic/structural features, coordination modes, ability to mediate magnetic exchange interactions between coordinated d and/or f-metal centers, and to work as efficient antenna ligands towards NIR lanthanide ions, make them suitable candidates for the preparation of the materials reported. In Chapter 1, the synthesis of a multifunctional mixed-valence FeIIFeIII anilate-based coordination polymer, obtained by using the chlorocyanilate ligand (ClCNAn2-), formulated as [TAG][FeIIFeIII(ClCNAn)3]•(solvate) (TAG = tris(amino)-guanidinium) is reported. This compound is characterized by single crystal X-Ray, at 150K and 10K, magnetic, mössbauer and conductivity measurements. Moreover, correlation of conductivity difference between anilate and pioneer oxalate based FeIIFeIII 2D coordination polymers are explained using theoretical calculations (small-polaron hopping model). In Chapter 2, the series of 2D layered coordination polymers based on chlorocyanilate ligand as building blocks formulated as [Ln2(ClCNAn)3(DMF)6]•(DCM)x (LnIII = Yb (1) (x = 0), Nd (2) and Er (3) (x = 2)) are reported. The synthesis, structural characterization, photophysical studies, time-resolved photoluminescence studies performed on both the bulk and nanosheets, effects induced by the exfoliation process on the photo-physical properties of the nanosheets are discussed. In Chapter 3, the new family of NIR-emitting lanthanide coordination polymers based on chlorocyanilate ligand and carboxylate ligands (di-hydroxy-terephthalic acid (DOBDC) and tetrafluoroterephthalic acid (F4-BDC)), which are the commonly used ligands to obtain 2D layered materials are reported. These systems are formulated as [Ln4(ClCNAn)5(DOBDC)1(DMSO)10]•(DMSO)2 (LnIII - Yb (1), Er (2)) [Ln2(ClCNAn)2(F4-BDC)(DMSO)6] (LnIII – Yb (3), Er (4)). Structural characterizations along with time-resolved photoluminescence studies on these compounds are described. In Chapter 4, series of 2D layered coordination polymers based on chlorocyanilate ligand and DyIII are reported. These compounds are formulated as [Dy2(ClCNAn)3(DMSO)6] (1), [Dy2(ClCNAn)6(DMSO)6] (1'), [Dy2(ClCNAn)3(DMF)6](CH2Cl2) (3), (Me2NH2)2[Dy2(ClCNAn)4(H2O)2]•(DMF) (4). The synthesis, structural characterization along with its magnetic characterization is described. In Chapter 5, using the above-mentioned anilate ligands with the BEDT-TTF organic donor, purely organic semiconductors formulated as [BEDT-TTF]2[HClCNAn] (1) and [BEDT-TTF][HCl2An] (2) are obtained by electrocrystallization. Their structural characterization, transport properties and band structure calculation are reported. In Chapter 6, structural diversity and physical properties of П-d hybrid multifunctional paramagnetic molecular conductors obtained by combining BEDT-TTF and [Fe(ClCNAn)3]3- as conducting and magnetic carrier respectively are reported. These compounds are formulated as [BEDT-TTF]4[Fe(ClCNAn)3]•3H2O (1) and [BEDT-TTF]5[Fe(ClCNAn)3]2•2CH3CN (2). Their structural characterization, transport properties and magnetic properties are described. The framework of the thesis is as follows: Part I - General Introduction on Molecular Materials, State of the Art on Anilate-based MOFs and Coordination Polymers and Molecular Conductors together with aim of the work. Part II - Results and discussions, which is divided into 6 Chapters whose content has been summarized above. Part III - Conclusions and the Perspectives. Part IV - Annexes for additional information