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Zintl phases form hydrides either by incorporating hydride anions (interstitial hydrides) or by covalent bonding of H to the polyanion (polyanionic hydrides), which yields a variety of different compositions and bonding situations. Hydrides (deuterides) of SrGe, BaSi, and BaSn were prepared by hydrogenation (deuteration) of the CrB-type Zintl phases AeTt and characterized by laboratory X-ray, synchrotron, and neutron diffraction, NMR spectroscopy, and quantum-chemical calculations. SrGeD4/3–x and BaSnD4/3–x show condensed boatlike six-membered rings of Tt atoms, formed by joining three of the zigzag chains contained in the Zintl phase. These new polyanionic motifs are terminated by covalently bound H atoms with d(Ge–D) = 1.521(9) Å and d(Sn–D) = 1.858(8) Å. Additional hydride anions are located in Ae4 tetrahedra; thus, the features of both interstitial hydrides and polyanionic hydrides are represented. BaSiD2–x retains the zigzag Si chain as in the parent Zintl phase, but in the hydride (deuteride), it is terminated by H (D) atoms, thus forming a linear (SiD) chain with d(Si–D) = 1.641(5) Å.

Hydrides (deuterides) of the CrB-type Zintl phases AeTt (Ae = alkaline earth; Tt = tetrel) show interesting bonding properties with novel polyanions. In SrGeD4/3–x (γ phase), three zigzag chains of Ge atoms are condensed and terminated by covalently bound D atoms. A combination of in situ techniques (thermal analysis and synchrotron and neutron powder diffraction) revealed the existence of two further hydride (deuteride) phases with lower H (D) content (called α and β phases). Both are structurally related to the parent Zintl phase SrGe and to the ZrNiH structure type containing variable amounts of H (D) in Sr4 tetrahedra. For α-SrGeDy, the highest D content y = 0.29 was found at 575(2) K under 5.0(1) MPa of D2 pressure, and β-SrGeDy shows a homogeneity range of 0.47 < y < 0.63. Upon decomposition of SrGeD4/3–x (γ-SrGeDy), tetrahedral Sr4 voids stay filled, while the Ge-bound D4 site loses D. When reaching the lower D content limit, SrGeD4/3–x (γ phase) with 0.10 < x < 0.17, decomposes to the β phase. All three hydrides (deuterides) of SrGe show variable H (D) content.

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The synthesis and surface modification of upconverting nanoparticles (UCNPs) composed of a host lattice NaYF4 doped with sensitizers (Yb3+, Nd3+) and luminescent emitters (Er3+) were investigated for potential integration in biological applications.The fascination of NaYF4: Nd3+, Yb3+, Er3+ upconverting nanoparticles derives from their capacity to be excited in the biologically transparent window (650-950 nm) enabling deep tissue penetration. In particular, the ability to convert near infrared radiation into visible light (upconversion), which prevents autofluorescence and over-heating effect of biological tissues.In biological applications especially in vivo, morphology and size of the nanoparticles plays a crucial role in determination of cellular responses and fate in living organism. Heterogeneously sized nanoparticles, in contrast to uniform ones, might be distributed unevenly in the organism causing undesirable toxic side effects. Therefore, precise control of the nanoparticle size, distribution, and reproducibility were main tasks in the first part of this work. Colloidal upconverting nanoparticles were synthesized using coprecipitation method. Synthetic parameters such as reaction temperature (280-320 °C), and time (5-30 min) were used to tailor the nanoparticle morphology, crystal phase (cubic or hexagonal) and particle size (sub-10 - 20 nm). Integration of these nanoparticles in biological applications requires dispersibility in aqueous media. Hence hydrophobic UCNPs were surface-modified with low molecular weight ligands including O-phospho-L-threonine, alendronic acid, and PEG-phosphate ligands to generate water-dispersible UCNPs. Furthermore, in this work, photocrosslinking of diacetylenes is presented as an effective way to create robust UCNPs with a crosslinked shell. Finally, the protein corona formation on UCNPs coated with charged, zwitterionic and nearly neutral ligands was investigated. The composition of protein binding to UCNP is notably influenced by the surface charges of the UCNPs. Overall, the results obtained in the frame of this work show that the NaYF4: Nd3+, Yb3+, Er3+ UCNPS have the potential to replace conventional fluorophores in bioimaging applications due to their remarkable optical properties, as well as the derivatization flexibility of their surface

With their three-dimensional macromolecular structure and shape, and with their tuneable properties in both the inner and outer spheres, dendrimers are ideal model compounds in the nanometre range between 1 and 10 nm. The possibility to combine different properties within one macromolecule destines them for use in various high-end research fields such as medicine, pharmacy, biology, supramolecular chemistry, nanotechnology and material sciences. On the basis of their high end-group density and a compact, highly branched molecular structure, dendrimers are successfully investigated as carrier systems for active substances and metal ions (e.g. contrast agents for the visualisation of blood vessels), as templates for metal nanoparticles, as artificial enzymes with defined functions, and as materials for catalysis. / Dendrimere sind aufgrund ihrer dreidimensionalen Makromolekülstruktur und -form und ihrer steuerbaren Eigenschaften sowohl an der Oberfläche als auch im Molekülinneren ideale Modellverbindungen im Nanometerbereich – sie sind zwischen 1 und 10 nm groß –, die vorzugsweise in der Medizin, Pharmazie, Biologie, Supramolekularen Chemie, Nanotechnologie und den Materialwissenschaften eingesetzt werden. Aufgrund ihrer hohen Endgruppendichte und der kompakten, stark verzweigten Molekülform werden Dendrimere unter anderem als Trägermaterialien und Transportsysteme für Wirkstoffe und Metallionen, zum Beispiel als Kontrastmittel zur Visualisierung von Organen und Blutgefäßen, als Template für metallische Nanopartikel, zur Erzeugung künstlicher Enzymfunktionen und in der Katalyse erfolgreich untersucht.

In this dissertation, diverse strategic designs of energy storage materials were explored. The main aims were: affordability and high-performances. I) on eco-efficient synthesis of 1D intercalation compounds was described; a low-temperature aqueous solution synthesis of nanostructured 1D (molybdenum trioxide) MoO3 was developed. Subsequent self-assembly of the fibers to form large-scale freestanding films in paper-like structure was achieved without any assistance of organic compounds. Indeed, the whole processes, from synthesis to assembly of obtained materials, do not require toxic organic solvents. As an example of the application of our synthesized materials, 1D MoO3, having the width in 50−100 nm, with the length in micro scale, and with thickness in ~10 nm, and the macroscopic oxide papers consisting of 1D MoO3 and carbon materials were applied as the cathode and anode to lithium-ion batteries, respectively. As a cathode material, the 1D MoO3 showed a high rate capability with a stable cycle performance up to 20 A/g due to a short Li+ diffusion path along [101] and less grain boundaries which were achieved by the precise nanostructure control. As an anode material, the composite paper showed the first specific discharge capacity of 800 mAh/g. These findings above indicate not only an affordable, eco-efficient synthesis and assembly of nanomaterials but also show a new attractive strategy towards a possible whole aqueous process for a large-scale fabrication of freestanding oxide papers without any toxic organic solvent. II) a new energy storage principle using polymeric frameworks was investigated. The new energy storage concept can deliver both high power and high energy. This is because of the novel energy storage nature of designed artificial polymeric frameworks which is different from classical energy storage mechanisms. The main novel discovery was as follows; since CTF-1 is linear stepwise p- and n-dopable polymer, therefore, this framework can store energy as a cathode in the wide working potential with both cation below 3 V versus Li/Li+ and anion above 3 V versus Li/Li+ by Faradaic reaction. Due to this feature, CTF-1 can store high specific capacity of 540 mAh/g. As the result the new energy storage concept which can deliver both high power and high energy was discovered by using a novel polymeric cathode. Unlike typical organic electrodes in sodium battery systems, the CTF-1 has a high specific power of 10 kW/kg, specific energy of 500 Wh/kg, and over 7,000 cycle life retaining 80 % of its initial capacity in half-cells. Indeed, all-organic energy storage devices based on CTF-1 suggested a possibility towards an extremely affordable energy storage device. Recent research on such artificial polymeric frameworks suggests their huge variability to utilize different functional structures which could even further increase power and energy even further when using different starting monomers. This would significantly extend the possibilities of electrical energy storage devices for a sustainable society based on our result. From this point of view, our research strategy which combined the experimental and theoretical study would be a model for further development of this field.

In summation, this thesis provides a panoramic view of the prevailing challenges and potential solutions associated with achieving unparalleled energy and power densities in GDIBs where graphite reigns supreme as the cathode material of choice. By comprehensively tackling these challenges and integrating the recommended strategies, there lies a promising path ahead for the evolution of advanced dual-ion batteries. Such advancements could redefine benchmarks in en-ergy storage, heralding an era of more efficient and versatile applications.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as a new generation of conduct-ing MOFs for electronics. However, controlled synthesis of thin-film samples with high crystallinity and defined layer orientation, which is beneficial for achieving high-performance devices and reliable structure-property relationship, has remained a challenge. Here we develop a surfactant-directed two-step synthesis of layered 2D c-MOF films based on benzene and triphenylene ligands linked by copper-bis(diimino) complexes (HIB-Cu and HITP-Cu, respectively). The achieved layered 2D c-MOF films are featured as free-standing, in-plane oriented, and polycrystalline films with domain size up to ~ 8000 nm2 and a tunable thickness in the range of 8 - 340 nm. Benefiting from the intrinsic elec-trical conductivity and quasi-one-dimensional pore channels, a HIB-Cu film based chemiresistive sensor is construct-ed, displaying effective humidity sensing with a response as fast as ~ 21 s, superior to the reported MOF-powder-based chemiresistive sensors (in the orders of minutes).

Correction to: Nature https://doi.org/10.1038/s41586-021-03842-3