Microporous Materials & Mechanochemistry

Hybrid organic-inorganic microporous materials with desired functionalities

The revolutionary process of turning from molecules to supramolecules that took less than half a century has paved the way for the abundance of new applications-oriented fields of endeavor, where metal-organic framework (MOF) chemistry has emerged as the most widely investigated today.1 The basic tenet underlying this area of science is that by taking a one of limitless number of 2D or 3D nets as a blueprint one can construct a crystal framework by a simple combination of carefully chosen inorganic (connectors) and organic (linkers) building blocks,2 with the resulting supramolecular structure exhibiting desired functions and properties. This novel concept in chemistry has captured imaginations of many chemists aware of the growing opportunity for the development of new generation of zeolite-like materials whose structure, chemical composition and functions can be engineered to meet one of several applications. In fact, intensive studies in this area have been particularly fruitful to deliver a range of advanced materials with intriguing novel properties, record-breaking parameters, and wide range of applications to be employed in, including storage and separation of small molecules and highly selective heterogeneous catalysis. The great potential and significance of this technology has not been overlooked by chemical industry, being BASF the first company that produces MOFs with BASOLITE trademark for their experimental purposes.3

We are aimed at synthesis and characterization of novel organometallic building units based on transition or 12 and 13 group metal complexes of multifunctional organic ligands, and further evaluation of their utilities as precursors of hybrid organic-inorganic microporous materials with desired functionalities. The important objectives are to develop novel advantageous methods of materials fabrication by self-assembly processes in liquid or solid state and evaluate the possibility of their subsequent post-synthetic modification by taking advantage of the high reactivity of M-C bonds existing in the obtained metallosupramolecular architectures. The highlighted investigations would significantly contribute to fundamental understanding of the nature of self-assembly and mechanochemical processes providing simultaneously opportunities for original discoveries in the field of materials science.

Development of synthetic procedures of hybrid inorganic–organic materials

The evolution of our research interest towards materials science of metal-organic frameworks and other metallosupramolecular architectures was mainly driven by the effort to exploit our experience and knowledge gained through long-term studies on the 12 and 13 group organometallic complexes in applications-oriented research, and this process has been accelerated recently by the original discoveries that have been done in our group. Importantly, we have been able to generate a series of non-covalent open-channel network materials based on zinc oxocarboxylate or related zinc clusters. Others demonstrated that grinding in the presence of a small quantity of liquid can be utilized as a rapid and efficient method for screening, as well as for the quantitative synthesis of hybrid inorganic–organic materials.

Mechanochemistry as a novel tool for cluster-to-cluster transformation

The interest in mechanochemistry results from the growing interest in environmentally friendly and sustainable chemical processes. The mechanosynthesis method proved to be rapid and provided quantitative yields without solvents or external heating.1 Moreover, the most important benefit is the availability of reactants and products that are difficult to encounter in conventional solution-based synthesis. Very recently our group reported the possibility to obtain new metastable metal alkoxide structures by mechanochemical cluster-to-cluster transformation (Scheme 5).2 Therefore we are going to extend this emerging research area into other metal alkoxides or hydroxides and investigate their transformation under mechanochemical conditions. We are also concerned with developing a novel, unexploited solvent-free synthetic procedure based on grinding in solid state as our primary results clearly indicated viability of this route for the generation of ZnO nanoparticles and organic-inorganic hybrid materials.