Synthesis of Sulfonate-Containing Group 13 Metal–Organic Frameworks

The [M(OH)(O2CR)2]∞ infinite chain is a prevalent inorganic building unit in the construction of metal–organic frameworks (MOFs). Knowledge of its mechanism of formation enables the development of more efficient MOF syntheses that are required to advance the applications of these materials. To this end, identifying relevant intermediates is expected to enhance the mechanistic understanding of the formation of the infinite chain. Seeking to investigate the potential intermediary role of "incomplete infinite chains" in the formation of group 13 infinite chain MOFs, we employed linkers containing chelating functional groups to arrest self-assembly along a polymerizable axis. This resulted in the formation of four novel sulfonated frameworks comprised of incomplete infinite chains (YCM-61, -71, -72, and -73, YCM = Youngstown Crystalline Material). Notably, one of the frameworks (YCM-61) presents a solid-state Raman vibration bearing similarity to that previously ascribed to a MIL-53(Al) intermediate.