A series of soft-chemistry, topotactic, multistep synthesis methods were developed to synthesize a variety of metastable functional materials. Throughout the thesis, a focus is placed on how crystal structure, bonding, and atomic interactions play a role on determining function or properties of the material. Materials synthesized were fully characterized, including Rietveld refinement (when high-resolution diffraction was available), stoichiometry characterization by ICP and titration, thermal stability, and decomposition products. Properties investigation was completed where applicable, including electrochemical cycling of Li-ion cathode material candidates and magnetic properties characterization for frustrated systems with competing coupling pathways. The first method presented - solvothermal reduction - was used for the exploratory synthesis of materials with NiO2 square planar units in an extended lattice. As phases with square planar CuO2 units garnered much attention in the 1990s as high-temperature superconductors, NiO2 analogs may exhibit similar properties. Synthesis of the infinite-layer compound La4Ni3O8 was used as the test case for the solvothermal reduction method. A full discussion on reaction variables as well as reactions routes is presented.A family of fluorinated materials is also presented, prepared using multistep fluorination methods. The oxyfluoride SrFeO2F was prepared via the infinite-layer intermediate SrFeO2, the first phase with FeO2 square planar units in an extended lattice. An investigation in the effects of experimental conditions on local coordination is presented for this material. The multistep fluorination of La4Ni3O8 is also presented, where two different fluorinated phases were prepared - La4Ni3O8F1 and La4Ni3O8F2. The complex and anisotropic structure of these phases is discussed, including the interesting T to T' transformation. Lastly, a solvothermal fluorination method is developed and demonstrated in the synthesis of Sr2Co2O5F. The effect of the low-temperature synthesis on product purity is discussed as well as the importance of experimental conditions.The third technique described in this thesis is the MuRE method for the synthesis of novel layered materials with spin frustrated Cd-I2 type layers. A series of materials with different transition metals is presented, focusing on the topotactic nature of the reactions. The synthesis of a group of Co2+/3+ phases allowed for the further exploration of the low temperature magnetic phase diagram for Co2.5+/Co4+ in layered phases with Cd-I2 type layers. Thermal stability, electrochemical characterization, and reaction kinetics are also investigated.Lastly, the Whole Powder Pattern Modeling algorithms are described and shown to be a powerful tool in the nanoparticle analysis. Particle size and strain values were extracted from powder patterns of nanoparticles with high accuracy.
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