## 2 Metal-Organic Frameworks
One of the most important characteristics of MOFs, which has brought them to the forefront of porous materials, is their crystallinity and the ability to be isolated in the form of single crystals. This allows their detailed structural characterization and the in depth understanding of their structure while enabling the strong correlation between structure and properties. This is enabled through Single Crystal X-ray Diffraction (XRD) [57], which is usually combined with Powder X-ray Diffraction (XRD), contributing to the verification of phase purity, especially in up-scaled reactions, as well as the estimation of the structure stability under different environments (e.g., solvents, temperature, air) [58]. Furthermore, the porosity of these materials, which usually present complex porous networks with smaller and larger interconnected cavities, is mapped through detailed Ar or N\({}_{2}\) sorption experiments at 87 K and 77 K, respectively. Through these measurements we can calculate the total pore volume of the materials, their specific surface area employing the Brunauer-Emmett-Teller (BET) method [59] and their pore size distribution. Additionally, the morphology of the materials can be studied using microscopy methods, such as Scanning Electron Microscopy (SEM). Also, their thermal stability in air or under an inert atmosphere is studied employing Thermogravimetric Analysis. Spectroscopic studies as Fourier transform infrared (FT-IR) and UV-Vis spectroscopy can also be employed to further comprehend the physicochemical characteristics of such materials. Furthermore, as far as their antimicrobial assay is concerned, microscopy as SEM or Transmission electron microscopy (TEM) can also be employed to study the damage on the pathogens' cells after their treatment with MOF formulations. Furthermore, protocols such as ASTM E2149-13a [60] and the microtiter broth dilution technique [61; 62] can be utilized. In this framework, MOFs' utilization in agriculture and pesticide technology represents a rapidly expanding area of application [63]. Specifically, their controlled pore size, high surface area, ease of chemical modification, and unique network structure render them promising candidates for the loading and controlled release of pesticides and other plant-protective compounds [64; 65]. Also, their physicochemical profile allows the potential for \"smart\" combination with a multitude of functional ingredients [66], such as nanoparticles, active organic molecules (photosensitizers, catalysts), and polymers, allowing for the development of intelligent platforms with improved stability and enhanced responsiveness under specific conditions, related to the soil and plant growth environment (e.g., pH, salinity, temperature). These characteristics make them suitable for loading selected active substances and releasing them under controlled conditions to ensure maximum effectiveness [37; 38]. Additionally, the freedom afforded by these materials regarding the selection of their building blocks enables not only the design of efficient active substance release systems but also the incorporation of molecules with desirable plant-protective action (e.g., aspartic acid, coumarin, fumaric acid, amino acids, zinc, copper) into their very framework, thereby enhancing the development of multifunctional systems with simultaneous action in different targeting areas [67]. To date, the international literature is continuously enriched with promising MOF-based materials aiming to crop protection through the control of phytopathogens, pest management, and weed management [68]. The first report on the use of MOFs as carriers for pesticide release dates back to 2015 (OPA-MOF, OPA: oxalate-phosphate-amine) for the gradual release of nutrient trace elements such as nitrogen (N) and phosphorus (P) [69]. Another significant contribution to the field was the MOF-1201 ([Ca\({}_{14}\)(I-lactate)\({}_{20}\)(acetate)8X] (X: C\({}_{2}\)H\({}_{5}\)OH, H\({}_{2}\)O)), based on the organic substituent L-Lactate and calcium metal ions.