The 21st century has seen a reinvention of how modern electronics impact our daily lives; silicon-electronics and organic electronics are currently at the core of modern electronics. Recent advances have demonstrated that conductive metal–organic frameworks (MOFs), as another unique class of electronic materials, are emerging to provide additional possibility for multifunctional electronic devices that brings us “MOFtronics”. Typically, two-dimensional conjugated MOFs (2D c-MOFs) are a novel class of layer-stacked MOFs with in-plane extended π-conjugation that exhibit unique properties such as intrinsic porosity, crystallinity, stability, and electrical conductivity as well as tailorable band gaps. Benefiting from their unique features and high conductivity, 2D c-MOFs have displayed great potential for multiple high-performance (opto)electronic, magnetic, and energy devices. In this review article, we introduce the chemical and synthetic methodologies of 2D c-MOFs, intrinsic influences on their electronic structures and charge transport properties, as well as multifunctional applications of this class of materials for MOFtronics and potential power sources for MOFtronics. We highlight the benefits and limitations of thus-far developed 2D c-MOFs from synthesis to function and offer our perspectives in regard to the challenges to be addressed.

Correction for ‘Two-dimensional conjugated metal–organic frameworks (2D c-MOFs): chemistry and function for MOFtronics’ by Mingchao Wang et al., Chem. Soc. Rev., 2021, 50, 2764–2793, DOI: 10.1039/D0CS01160F.

We present an autonomous, chemical logic gate based on a switchable metal–organic framework (MOF) composite, containing carbon nanoparticles and a Pt catalyst. The switchable MOF composite performs as AND logic gate. Hydrogen and oxygen gas streams serve as binary inputs. Catalytically formed water induces a structural transition (crystal volume expansion) of the MOF, and as a consequence, a detectable drop in conductance of the composite as a ‘true’ output only if both gases come in contact with the composite.

The porous materials discussed in this dissertation are metal-organic frameworks (MOFs) and porous liquids. Due to their high surface areas, tunable structures, and controllable porosities, MOFs have been explored for a wide variety of drug delivery applications. In chapter 2, MOFs have been used as magnetothermal-triggered release carriers through spatially distributed iron oxide nanoparticles within MOF matrix as a magnetic heating mediator and surface-grafted thermal-responsive nanocap as an alternating magnetic field (AMF)-responsive gatekeepers, achieving monitoring of drug release via external AMF by a conformational change of nanocap. In chapter 3, MOF, as a non-toxic loading carrier, encapsulate naringin, a natural product to serve as a multifunctional bio-platform capable of treating Gram-positive bacteria and certain cancers by slowly and progressively releasing the encapsulated naringin as well as improving and modulating immune system functions through the synergies between naringin and MOF. In chapter 4, porous liquid with unique solvent-free fluidity properties as a drug delivery platform for the first time. The interaction between hollow silica nanoparticle and polymerized ionic liquid, followed by ionic grafting brush of poly (ethylene glycol) telomer, makes this designed porous liquid responsible for high drug-loading and pH-responsive drug-releasing abilities along with slow degradation behavior. In addition to their high loading and controlled release, In vitro cell viability and cell uptake are also studied, thus opening up new opportunities for long-term chemotherapy.

The present thesis provides a systematic investigation of coordination polymers of 3d, rare-earth (4f) and main group element (Bi) using both rigid aromatic, flexible aliphatic linkers. Luminescent sensing behavior towards nitro aromatics, metal ions and ferroelectric behavior have been investigated using some of the prepared compounds. The possible usefulness of lone pair on the structure has been investigated using bismuth based coordination polymers. The thermal and optical behavior of lanthanide coordination polymers (Ce, Pr and Nd) have also been studied. Chapter 1 An Overview of Coordination Polymer (CP) Compounds This chapter presents a brief introduction to coordination polymer (CP) compounds. Starting from the brief historical background on coordination compounds, this chapter shed light on some earlier developments in this family of compounds by Yaghi, Robson and others. The usefulness of carboxylate and imidazolates in construction of some important coordination polymer compounds like MOF-5, HKUST-1, ZIFs, MIL-53, UiO-66, CD-MOF-1 etc has been described in detail along with its properties. The coordination polymers exhibit many important properties and some of the properties like sorption, separation, ionic conductivity, catalysis and ferroelectricity have been discussed briefly and summerized. Chapter 1 also provides the general synthetic and characterization approaches that have been employed during the present studies. Chapter 2 Part A: Adenine Based Coordination Polymers with Cyclohexane dicarboxylic acids This chapter presents the synthesis, structure and properties of four new coordination polymers [Zn4(C8H10O4)2.5(C5H4N5)3.2H2O].7H2O.2DMA (I), [Cd3(C8H10O4)2(C5H4N5)2.H2O] (II), [Cd(C8H11O4)2(C5H5N5)2.2H2O] (III), [Cd(C8H10O4)(C7H8N5O).H2O]. 4H2O (IV), (CHDA = cyclohexane dicarboxylic acid, ad = adenine, DMA = dimethylacetamide, 9-HEA = 9-hydroxyethyl adenine). The compound I and II forms three-dimensional structure having distinct arrangements of 1,4-CHDA and adenine units with Zn and Cd metals respectively. The molecular complex unit is observed in compound III with 1,2-CHDA and adenine. Compound IV forms two-dimensional structure with 9-HEA and 1,2-CHDA. The observation of base-pairing interactions in the above compounds is noteworthy. In compounds I, II and IV amino groups are appears to be free and utilized for the detection of nitro aromatic explosives through fluorescence quenching. The results revealed that the emission behavior of the present compounds is greatly influenced by the hydroxyl nitroaromatic analyses like indophenol, dinitrophenyl and trinitrophenols with very low detection limits. The compound I also exhibits considerable sensitivity towards metal ion detection, especially Fe2+/Fe3+, Cr3+, Ag+ and Hg2+ ions in solution. The presence of free nitrogen sites in compound II has been explored for the base catalyzed Knoevenagel condensation reaction, the quantitative yields are observed with various aldehyde substrates. Part B: Adenine Based Coordination Polymer with Oxydiacetic acid: [Cd2(C4H4O5)2(C5H5N5)].H2O.DMA The synthesis, structure and properties of a Cd based coordination polymer with oxydiacetic acid and adenine, [Cd2(C4H4O5)2(C5H5N5)].H2O. DMA is described. The compound has a two-dimensional structure formed by the connectivity involving Cd and oxydiacetic acid. The adenine ligand binds with the Cd metal center through the pyrimidine nitrogen and hangs in the inter layer spaces. The layers are stacked in a ABAB.... fashion and the inter layer spaces occupied by the dimethyl amine and water molecules. The water molecules are very labile and its removal can be accomplished by heating the sample at 100°C, which is also confirmed by the single crystal XRD, PXRD and IR studies. The availability of free amino groups of adenine molecule has been utilized for the detection of nitroaromatics, especially nitrophenols with good sensitivity. The amino group was also found to be useful in catalyzing Knoevenagel condensation reactions. Chapter 3: Rare-Earth Metal Carboxylates: Ln2(µ3-OH)(C4H4O5)2(C4H2O4)].2H2O [Ln=Ce, Pr and Nd] This chapter describes synthesis, structure and properties of series of rare-earth based compounds, [Ln2(µ3-OH)(C4H4O5)2(C4H2O4)].2H2O (Ln = Ce, Pr and Nd). The malic acid and fumaric acid form part of the structure. The lanthanide centers are connected by the malate units to form a two dimensional layers, which are pillared by fumarate units forming the three-dimensional structure. Overall, structure can be described as I2O1 type inorganic in two-dimension (Ln-O-Ln layers) and organic in one dimension. The extra framework water molecules form a dimer and occupy the channels. The robustness of the framework was reflected in terms of facile removal and reinsertion of the water molecules, which is also confirmed by single crystal XRD, variable temperature IR and cyclic TGA study. The presence of water dimers and weakly interacting water chain suggested the possibility of proton migration in these compounds. Proton conductivity studies reveal the conductivity values of ~2.85 x 10-6 Ω-1cm-1 at 98% relative humidity. The optical studies revealed an up-conversion behavior involving more than one photon for the neodymium compound. Chapter 4: Bismuth Carboxylates with Brucite and Fluorite Related Structures The synthesis, structure and properties of three new bismuth based coordination polymers have been described in this chapter. The compounds [C4N2H10][Bi(C7H4NO4)(C7H3NO4)].H2O (I), [Bi(C5H3N2O4) (C5H2N2O4)] (II) and [Bi(µ2-OH)(C7H3NO4)] (III) were isolated employing hydrothermal condition with three different heterocyclicdicarboxylic acids, 3,6-pyridinedicarboxylic acid, 4,5-imidazoledicarboxylic acid and 3,4-pyridinedicarboxylic acid respectively. The structures of all the compounds have linkages between Bi2O2 and the corresponding dicarboxylate forming a simple molecular unit in I, a bilayer arrangement in II and a three-dimensional extended structure in III. The topological arrangement of the nodal building units in the structures resembles brucite related layers in II and fluorite related arrangement in compound III. By utilizing the secondary interactions, the structure of III can be correlated to a Kagome related net. The observation of such classical inorganic related structures in the bismuth carboxylates is noteworthy. Heterogeneous catalytic studies indicate Lewis acidic nature in the bismuth center in all three compounds. Chapter 5: Solvent dependent Delamination, Restacking and Ferroelectric studies in a Two-Dimensional Compound [NH4][Ag3(C9H5NO4S)2(C13H14N2)2].8H2O This chapter describes synthesis, structure, water dependent delamination/restacking and ferroelectric behavior in a layered coordination polymer compound, [NH4][Ag3(C9H5NO4S)2(C13H14N2)2].8H2O. The compound has a two-dimensional structure with the water molecules occupying the inter-lamellar spaces. The lattice water molecules can be fully removed and reinserted, which accompany the crystalline-amorphous-crystalline transformation. This transformation resembles the collapse/delamination and re-stacking of the layers. This transformation has also been investigated by in-situ IR and PXRD studies. The presence of a natural dipole (anionic framework and cationic ammonium ions) along with the non-centrosymmetric space group gives rise to a room-temperature ferroelectric behavior to the compound with saturation polarization (Ps) of 1.95 μC/cm2 and remnant polarization of 0.63 μC/cm2. The temperature dependent dielectric measurements indicate that the ferroelectric-paraelectric transformation occurs at 320 K. The ferroelectric-paraelectric transformation also follows the crystalline-amorphous-crystalline transitions.

Understanding the supramolecular interactions governing the self-assembly of molecular building blocks upon surfaces is fundamental to the design of new devices such as sensors or catalysts. Successful heterogeneous enantioselective catalysts have relied upon the adsorption of ‘chiral modifiers’, usually chiral amino acids, onto reactive metal surfaces. One of the most researched examples is the hydrogenation of β-ketoesters using nickel-based catalysts. The stability of the chiral modifiers upon catalyst surfaces is a major obstacle to the industrial scale-up of this reaction. In this study, the replacement of conventional modifiers with porous, chiral and functionalised self-assembled networks is investigated. Perylene-3,4,9,10-tetracarboxylic diimide (PTCDI) and melamine (1,3,5-triazine,-2,4,6-triamine) have been shown to form hydrogen bonded networks on Ag-Si(111)√3x√3R30° in ultra-high vacuum (UHV) and Au(111) substrates in UHV and ambient conditions, these networks are capable of hosting guest molecules. These networks are investigated further in this study. In UHV, the behaviour of the components and network formation on Ni(111) is probed using scanning tunnelling microscopy (STM) and temperature-programmed desorption (TPD). The stability of the PTCDI-melamine network on Au(111) was analysed using TPD. Metal coordination interactions between each of the network components and nickel upon the Au(111) surface were examined by STM before testing the ability of the network to act as a template for metal growth. Finally, a number of polymerisation reactions are investigated with a view to replacing chiral modifiers with porous, chiral, functionalised covalent networks. Periodic covalent networks should possess the greater chemical and thermal stability required for more widespread use. In UHV and ambient conditions, STM is used to monitor the progress of surface-confined reactions on Au(111) and characterise the resultant covalent structures.

A flexible Metal–Organic Framework Zn4O(BenzTB)3/2 (DUT-13) was obtained by combination of a tetratopic linker and Zn4O6+ as connector. The material has a corundum topology and shows the highest pore volume among flexible MOFs. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

The synthesis of five homoleptic transition metal complexes of bis-(phenyl)-diisoindol-aza-methene is described together with the optical, electrochemical and thermal properties of these compounds. Additionally, crystal structures for the Co and the Zn complex are reported. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

La conception de nouveaux matériaux fonctionnels a une longue histoire. Durant les deux dernières décennies, le domaine des polymères organiques et inorganiques a attiré l'attention des chercheurs. Plus important encore, les matériaux poreux tels que les Metal Organic Frameworks (MOFs), en anglais, Covalent Organic Frameworks (COFs), en anglais, ainsi que des polymères de coordination poreux sont maintenant étudiés de manière intensive en raison de leurs applications potentielles, comprenant le stockage de gaz, la séparation de gaz, la catalyse et la détection. D'un autre côté, les polymères contenant du Pt ont montré l'application potentielle dans les cellules solaires et les diodes électroluminescentes. Le mémoire est divisé en trois sections principales présentant des résultats nouveaux. Dans la première section, le chapitre 2 traite essentiellement de la formation de polymères de coordination (CP) avec des sels CuX (X = Cl, Br, I) et trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1), soit dans le PrCN ou PhCN. Les polymères résultants sont soit 2D (bidimensionel) ou 1D (unidimensionel). Cependant, en presence de PrCN ou de PhCN, le CP 2D obtenu avec le CuBr n'a pas incorporé de solvant dans ses espaces vides. D'autre part, le CP 2D et le reste des CP 1D obtenus avaient soit des molécules de solvant de cristallisation dans leurs cavités ou coordonnés au cuivre sur la chaîne. Les unités cuivre-halogénures étaient soit des rhomboïdes Cu2X2 ou le cubane Cu4I4. Leurs mesures photophysiques en présence et en l'absence de molécules de solvant de cristallisation ont été effectuées. En outre, la porosité du CP a été évaluée par BET (N2 à 77 K). Le vapochromisme du CP 2D sans solvant et des CP 1D ont été étudiés, ainsi que les mesures de sorption du CO2 ont été effectuées. De plus, nous avons utilisé CuCN et L1 dans MeCN pour former de nouveaux CP’s. Ceci est rapporté dans la deuxième section, le chapitre 3. Le CP obtenu était inattendu : L1 s’est rompu et du cyanure CN‾ s’est coordonné sur le Pt. Ceci a conduit à la formation d’un CP 1D zigzag. Généralement, les CP sont formés avec L1 via des liens Cu-S ou/et Cu([éta]2-C≡C), mais pas dans le cas du CuCN qui lui forme une chaîne 1D (CuCN)n où le L1 rompu se lie avec cette chaîne via un lien Cu-N. Les propriétés photophysiques et de stabilité thermique ont été étudiées. La troisième section (Chapitre 4) traite d'une exploration des CP formés par la reaction des sels CuX (X = Cl, Br, I) et le trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) ou le trans-[p-MeSC6H4C≡C-Pt(PEt3)2-C≡CC6H4SMe] (L2) dans du MeCN afin de trouver des tendances. L'utilisation de L1 a donné lieu à un CP 2D ou 1D CPs avec le MeCN piégé à l'intérieur des cavités, il y a de l’espace vide. L2 a conduit uniquement à des CP 1D sans molecules de solvant de cristallisation. Des analyses thermogravimétriques, photophysique et des mesures d’adsorption de gaz (uniquement pour ceux avec du solvant) ont été étudiées. / Abstract: The design of new functional materials has a long history. For the past two decades, the field of organic and inorganic polymers has attracted attention of researchers. More importantly, porous materials such as Metal Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs) as well as porous coordination polymers are now being intensively studied due to their potential applications including gas storage, gas separations, catalyst and sensing. On another hand, Pt-containing polymers have shown potential applications in solar cells and light emitting diodes. The masters’ thesis is mainly divided into three main sections presenting new results. In the first section; Chapter 2 mainly discusses the formation of coordination polymers with CuX salts (X= Cl, Br, I) and trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1), in either PrCN or PhCN. The resulting polymers obtained were 2D (bidimensional) CPs or 1D (unidimensional) CPs in all cases. However, 2D CPs obtained when CuBr salt is used by either using PrCN or PhCN did not incorporate the solvents in their cavities. On the other hand, the 2D CP and the rest of 1D CPs obtained had either the crystallization molecules in the cavities or coordinated to the copper cluster. The copper-halide clusters were either the rhomboids Cu2X2 fragments or the step cubane Cu4I4. The photophysical measurements in the presence and absence of solvent crystallization molecules were performed. In addition, the porosity of the CPs was evaluated by adsorption isotherms. The vapochromism of the solvent-free 2D and 1D CPs were investigated as well as CO2 sorption measurements were perfomed. Furthermore, we then attempted to use CuCN and L1 in MeCN which is reported in the second section as Chapter 3. The obtained CP was unexpected as L1 broke and a cyanide (CN‾) ion coordinated to the Pt atom leading to the formation of zigzag 1D CP. The coordination bonds Cu-S or/and Cu([eta]2-C≡C) were generally observed with L1, but not in the CuCN case. Instead a 1D chain of (CuCN)n was made and the broken L1 now binds the chain via a Cu-N bond. The photophysical and thermal stability properties were studied. Lastly, the third section, Chapter 4 deals with a potential predictability of CP formation by using CuX salts (X= Cl, Br, I) and either trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) or trans-[p-MeSC6H4C≡C-Pt(PEt3)2-C≡CC6H4SMe] (L2) in MeCN as the solvent. The use of L1 resulted in either 2D or 1D CPs with the MeCN trapped inside of the cavities while L2 resulted in 1D CPs without MeCN being present in their cavities. The thermogravimetric, photophysical as well as gas sorption measurements (only for those with crystalisation molecules) were perfomed.

Ce travail de thèse ce focalise sur la croissance et la caractérisation de Nanofils (NFs) et de Microfils (µFs) de GaN. L'élaboration de telles structures est obtenue par épitaxie en phase vapeur d'organométalliques à partir de deux stratégies de croissances: l'une dite auto-organisée, réalisée sur substrat saphir, l'autre appelée sélective ou localisée, obtenue sur template GaN de polarité Ga. Quelque soit la stratégie employée, nous montrons que la croissance de structures verticales suivant l'axe c requièrent l'utilisation d'un flux de NH3 et d'un rapport V/III faible, lorsque nous les comparons avec les valeurs utilisées pour la réalisation de couches planaires de GaN. Les paramètres et les étapes de croissances ayant une influence sur le rapport d'aspect (hauteur/diamètre) sont étudiées et mises en évidence pour chacune des stratégies employées. Par ailleurs, les mécanismes de croissance ainsi que les propriétés structurales et optiques de ces objets sont caractérisés par MEB, MET, CL et µPL. En particulier, les expériences réalisées sur les µFs auto-organisés permettent d'observer et d'expliquer l'origine de la double polarité, de mettre en lueur la différence d'incorporation de dopants/d'impuretés entre les domaines Ga et N, d'identifier la présence de deux sections de propriétés électriques et optiques différentes, et de révéler la présence de deux types de résonances optiques: des Modes de galerie et des Modes de Fabry-Perot. D'autres part, nous étudions la courbure des dislocations vers les surfaces libres des NFs localisés et µFs auto-organisés, et pointons la présence de fautes d'empilement basales dans des régions de faibles dimensions. / This work focus on growth and characterization of GaN Nanowires (NWs) and Microwires (µWs). Such structures are obtained by Metal Organic Vapor Phase Epitaxy with two growth strategies: one called self-organized which is realized on sapphire, and the other named selective area growth which is obtained on a GaN Ga-polar template. Whatever the growth strategies employed, vertical growth of structures along the c axis requires the use of a low NH3 flux and V/III ratio, when they are compared with values used for planar growth of GaN. The influence of growth parameters and growth steps on aspect ratio (height/diameter) are studied and highlight for each growth strategies employed. Beside, growth mechanisms and structural and optical properties of such objects are characterized by SEM, TEM, CL and µPL. In particular, experiments realized on self-organized µWs enable us to observe and explain the origin of the double polarity, to highlight the dopants/impurities incorporation difference between Ga and N-domain, to identify two sections with differences in electrical and optical properties, and to reveal the presence of two types of optical resonances, identify as Whispering Gallery Modes and Fabry-Perot Modes. On the other hand, we study the bending of dislocations on free walls of localized NWs and self-organized µWs, and pointed out the presence of basal stacking faults in regions of small dimensions.