Exploring the Solid-State Properties of Phosphine Coordination Materials

University Of Texas At Austin, Austin TX

Investigators

Abstract

Non-Technical Summary This project involves the preparation of a new family of crystalline porous materials that display desirable properties, which can be exploited in a range of applications relating to energy and the environment. Porous materials are of critical importance in many large-scale processes, such as water purification, the separation and purification of gases, polymer synthesis, environmental protection by trapping of toxic chemicals in waste streams, and many others. It is important to explore the synthesis of new porous materials that can be designed to offer enhanced properties. With support of the Solid State and Materials Chemistry Program in the Division of Materials Research, the major goals of this research activity directly relate to this challenge, and include the synthesis and application testing of new materials that incorporate previously unexplored chemical functionalities. This project incorporates a new and innovative international student exchange program, which is aimed at inspiring undergraduate students to become engaged in research-based studies. The program also provides students a unique and invaluable opportunity to become fully acquainted with the culture of international collaboration in the sciences, through a period of study abroad at one of several outstanding partner universities across the globe. Technical Summary The goals of this research activity involve the preparation of a new family of metal-organic framework (MOF) materials, using a specific synthetic strategy that provides access to materials with previously inaccessible chemical reactivity. MOFs are crystalline, polymeric solids that contain precise molecular architectures and exhibit inter-connected networks of small pores (0.5-5.0 nm), which are accessible to a broad range of 'guest' adsorbates. MOFs have already shown great promise as materials for high capacity gas storage, and for sequestration of small molecules and other species such as heavy metal ions. Their broad applicability is derived from extreme design flexibility, as a function of the components used in their preparation. The Humphrey group has established synthetic approaches to prepare MOFs based on tailored organophosphine and metallic complexes based on phosphine ligands. Phosphine-based complexes are important as reactive catalytic species that can induce small molecule activation; it is therefore of timely interest to incorporate such reactivity into MOF-type materials. In this project, phosphine complexes with well-defined open (unsaturated) metal sites are first synthesized and then used to construct porous MOFs. Subsequently, these materials are studied under a range of conditions to assess the binding and selective sequestration behavior toward guest species of direct relevance to future energy applications, and for molecular sensing. The project is ideally suited to teach young researchers a range of skills from molecular synthesis to solid-state materials chemistry and characterization.