The impact of ligand design on the structural properties and thermal stability of metal-organic frameworks MOFs is significant. MOFs are a class of porous materials composed of metal ions or clusters connected by organic ligands. The choice of ligands and their design can greatly influence the overall properties of the resulting MOF, including its structure, porosity, and thermal stability.1. Structural properties: The geometry, size, and functionality of the ligands can affect the overall structure of the MOF. For example, ligands with different geometries can lead to different topologies and coordination environments for the metal ions. Additionally, the size of the ligands can influence the pore size and shape, which in turn affects the MOF's ability to adsorb and store gases or other molecules.2. Thermal stability: The choice of ligands can also impact the thermal stability of MOFs. Stronger coordination bonds between the metal ions and the ligands can lead to higher thermal stability. Moreover, the presence of functional groups on the ligands can influence the overall stability of the MOF. For instance, ligands with electron-donating groups can enhance the stability of the MOF by strengthening the metal-ligand bonds.3. Tunability: The design of ligands allows for the tunability of MOFs' properties. By modifying the ligands' structure or introducing functional groups, researchers can tailor the MOF's properties for specific applications, such as gas storage, catalysis, or drug delivery.In summary, ligand design plays a crucial role in determining the structural properties and thermal stability of metal-organic frameworks. By carefully selecting and designing ligands, researchers can create MOFs with desired properties and functions for various applications.