Design, Synthesis, Characterization, and Evaluation of Boronate Ester-Linked Porous Materials: Covalent Organic Frameworks and Polymers of Intrinsic Microporosity

An array of porous boronate ester-linked materials is presented here. Beginning with evaluation of a series of alkylated covalent organic frameworks (COFs), insight into the influence of alkylation in the hexagonal COF pores on the hydrolytic stability of the B-O linkages led to development of a family of hybrid COFs (HCOFs). These HCOFs were made by incorporating a gradual ladder of alkylation into the COF pores and provided a synthetic method to dial in stability along with porosity for specific COF applications. Parallel research resulted in a new COF with incorporated phthalocyanine groups (CuPC-COF) which could lead to future semiconducting thin films. The synthetic strategy to produce an octahydroxy-phthalocyanine monomer and the typical COF characterizations of PXRD and gas uptake are reported. The newest materials produced are porous yet amorphous and are the first family of boronate ester-linked polymers of intrinsic microporosity (PIMs). This family utilized the kink in a spirobisindane bis-diol monomer along with linear and trigonal boronic acids to produce amorphous solids which are intrinsically microporous. The potential of these materials to form permeable membranes and gas storage/separation devices, along with an abundant list of alternative commercially available monomers, warrant further development and testing of these boronate ester-linked PIMs