Estudo de topologia e síntese racional de redes metalorgânicas

Abstract

The synthesis of novel, stable and robust metal-organic frameworks has been a major challenge. Particularly, reticular chemistry has proven to be an important source of approximations and principles that can be used in what is known as the "rational design" of these porous structures. The rationalization of synthesis can be achieved through the formation or modulation of building blocks, which can acquire different geometries and connectivity and may allow isoreticulated systems or new topologies. This work aimed to realize the rational synthesis of metal-organic frameworks, leading to the obtaining of novel crystalline systems, among which new coordination networks formed from molecular building blocks (secondary building units - SBUs and metalloligand - ML) stand out. Thus, seventeen new crystal structures are reported in the attempt to build MOFs: a homometallic and 1-periodic coordination polymer based on a dicarboxylate ligand (1); a series of 1-periodic coordinating polymers with mixed ligands, N- and O-donors (2-5); a 1-periodic coordination network involving the formation of a SBU 4-connected with paddle wheel type (7); a 2-periodic, binodal and edge-transitive coordination network with sql topology (8); multicomponent organic crystals (6, 9 and 10); the 3-periodic and binodal coordination network with seh topology (11); a 3-periodic and binodal coordination network with rtl topology (12); a 3-periodic coordination network formed from the closest packing of rods that are infinite SBUs (13); a series of 2-periodic and multicomponent (heterometallic) coordination networks using a metalloligand as a molecular building block (14-16) and the 2-periodic and homometallic coordination network formed from the decomposition of the metalloligand used (17). From the strategies used in the attempt to obtain MOFs by supermolecular building blocks (SBBs) approach, we sought to employ pre-assembled systems such as a two-dimensional coordination network with hcb topology and a metal-organic polyhedra (MOP-1). The products obtained from these synthesis attempts did not result from the increased dimensionality of the systems used as SBBs. All compounds obtained were duly submitted to the physicochemical characterization techniques and the crystalline structures and topology were determined from the single crystal X-ray diffraction.