Abstract

In this seminar, I will present some new results from our ongoing investigations into the synthesis of metal-organic frameworks as ‘solid-state ligands’ for the site-isolated coordination of low-valent metal complexes of industrial relevance to large-scale petrochemical conversions, for electrochemistry, and for chemical sensing of reactive gases (e.g., NH3 , SO2). In recent years, we have expanded our MOF -building ‘toolkit’ from the use of triaryl(phosphine) (PR3) ligands to analogues based on the heavier pnictogens (As, Sb & Bi). Surprisingly to some, SbR3 and BiR3 ligands are directly amenable to MOF synthesis under standard self-assembly conditions, opening-up a broad array of new opportunities to study catalysis in the solid-state, using structurally well-defined, low-valent metal complexes. Further, the MOF -based solid-state ligand approach offers opportunities to utilize donor atoms such as SbIII and BiIII in new ways that circumvent facile ligand de-coordination due to weak Lewis basicity (and often, moderate Lewis acidity). Equally it allows for the preparation of catalysis in uniquely geometrically strained environments, which could be considered as long-lived non-equilibrium states from a molecular coordination. perspective. New examples featured in this presentation will include new MOFs functionalized with ReI,OsI, RhI, IrI, PtII, AgI and AuI.

In a second area of research interest, a subset of phosphine-based MOFs containing mixtures of LnIII ions act as colorimetric chemical sensors, capable of resolving H vs D to fractions of a percent simply upon exposure to H2O /D2O/HOD mixtures. This MOF is presently under corporate development and customer deployment as a easy-to-use, field-deployable test-strip method for the displacement of legacy analytical techniques (e.g., NMR , FT-IR), which are time-consuming and expensive for isotopic chemical analysis.