Die strukturelle Vielfalt von Metallphosphonaten macht sie zu vielversprechenden Kandidaten für vielzählige Anwendungen, erschwert aber zugleich eine planmäßige Synthese. Die Untersuchung der Bildungsmechanismen kristalliner Übergangs-metallphosphonate stellt Zusammenhänge zwischen Synthesebedingungen und resultierender Struktur her. In dieser Arbeit wurden unterschiedliche Phosphonsäuren mit divalenten Metallionen umgesetzt und so verschiedene Metallphosphonate mit diversen Strukturen erhalten. Die Kristallstrukturen neuer Verbindungen wurden mittels Röntgenpulver-diffraktometrie aufgeklärt. Systematische Untersuchungen zeigten einen direkten Zusammenhang zwischen bestimmten Strukturmotiven und Eigenschaften der Verbindungen. Das Bestreben nach umweltfreundlichen und wirtschaftlichen Synthesemethoden wird durch die Mechanochemie erfüllt. Die zugrundeliegenden Reaktions-mechanismen liegen im Dunkeln, sodass Mechanochemie größtenteils als „trial and error“-Methode funktioniert. In situ Untersuchungen mechanochemischer Reaktionen erlauben die Aufklärung der Reaktionswege und weitere Optimierung der Prozesse. Nach der Optimierung des experimentellen Aufbaus wurde in dieser Arbeit eine Kombination der Methoden Röntgenpulverdiffraktometrie und Thermographie zur Aufklärung der Bildungmechanismen von Metallphosphonaten eingesetzt. Die Ergebnisse der in situ Untersuchungen zeigen die Bildung von Metallphosphonaten als dreistufigen Prozess, der über einen nicht-kristallinen Zustand verläuft. / The structural diversity of metal phosphonates makes them promising candidates for numerous applications, but at the same time makes planned synthesis difficult. The study of the formation mechanisms of crystalline transition metal phosphonates establishes correlations between synthesis conditions and resulting structure. In this work, different phosphonic acids were reacted with divalent metal ions to obtain various metal phosphonates with diverse structures. The crystal structures of new compounds were solved by X-ray powder diffraction. Systematic studies showed a direct correlation between certain structural motifs and properties of the compounds. The search for environmentally friendly and economical synthesis methods is met by mechanochemistry. The underlying reaction mechanisms are unclear, so mechanochemistry functions largely as a "trial and error" method. In situ studies of mechanochemical reactions allow the elucidation of reaction pathways and further optimization of processes. After optimizing the experimental setup, a combination of X-ray powder diffraction and thermography methods was used in this work to elucidate the formation mechanisms of metal phosphonates. The results of the in situ investigations show the formation of metal phosphonates as a three-step process proceeding via a non-crystalline state.

Porous metal phosphonate framework materials were synthesised by solvothermal reaction of bis(α-aminomethylenephosphonic acid) ligands with divalent and trivalent metal cations. The syntheses and characterisation by NMR and, where possible, single crystal X-ray diffraction of seven bisphosphonic acid ligands, including N,N′-piperazinebis(methylenephosphonic acid) (H₄L), its racemic and enantiopure (R) 2-methyl (H₄L′ and R-H₄L′) and 2,5-dimethyl (H₄L′′) derivatives, and N,N′-4,4′-bipiperidinebis(methylenephosphonic acid) (H₄LL) are reported. Syntheses of the known phase Y₂(LH₂)₃·5H₂O and the new phases, STA-13(Y) (St Andrews microporous material No. 13) and Y₂(R-L′H₂)₃·4H₂O, from reactions of Y(AcO)₃ with H₄L, H₄L′ and R-H₄L′ respectively are reported. The as-prepared and dehydrated structures of each phase have been determined from either laboratory or synchrotron powder X-ray diffraction data. Reaction of Y(AcO)₃ and H₄L′′ is shown to form a phase with a different structure. The features determining which structure crystallises are discussed. Syntheses of other rare-earth forms of STA-13 (Sc³⁺, Gd³⁺–Yb³⁺) and the porosity of each phase to N₂ are reported. STA-13(Y) is the most porous form with loadings of ∼3 mmol g⁻¹ and ∼4 mmol g⁻¹ for N₂ and CO₂ respectively. MIL-91(Fe) was synthesised for the first time from reactions of Fe³⁺ cations with H₄L. Its structure was confirmed by Rietveld refinement, but it was not porous. The first syntheses of [Fe₄L₁.₅(AcO)₁.₅(OH,H₂O)₃]·0.5NH₄5.5H₂O (L= L or L′) are reported, from reactions of H₄L or H₄L′ in the presence of an excess of Fe³⁺ cations. The phase is related to a previously reported Co phase. The synthesis of divalent metal bisphosphonate STA-12(Mg) (Mg₂(H₂O)₂L·5.6H₂O) was reported for the first time and its structure determined from single crystal X-ray diffraction. The dehydration behaviour of this material was compared with the known forms of STA-12. STA-12(Mg) is porous to both N₂ (∼5.5 mmol g⁻¹) and CO₂ (~ 8.5 mmol g⁻¹). Reaction of H₄LL with Co²⁺ and Ni²⁺ gave two materials isoreticular with STA-12, labelled STA-16(Co) and STA-16(Ni). The structures of both materials were solved from synchrotron powder X-ray diffraction data. On dehydration, STA-16(Co) undergoes a reversible structural transition to an unknown structure. By contrast, STA-16(Ni) retains the same symmetry in the dehydrated form and its structure was determined from synchrotron powder X-ray diffraction data. Both materials are porous to N₂, with an uptake of up to 22.2 mmol g⁻¹, and CO₂ with maximum loading of 21.7 mmol g⁻¹. NLDFT analysis of N₂ adsorption data confirm the crystallographically determined pore radii. Syntheses of other frameworks with divalent cations and initial reactions of H₄LL with trivalent cations are also reported.