2D MHPs incorporating diammonium cations not only show this rich and fascinating structural chemistry but also offer appealing functional properties for optoelectronic applications. Diammonium ligands have been considered in the photovoltaics field with, for example, the incorporation of propylenediammonium and trimethylenediammonium in FASnI3 leading to improved film morphology and optoelectronic properties. Ortho-, metaand para-isomers of (phenylene)di(ethylammonium) iodide have been used as passivating layers in perovskite solar cells boosting the efficiency and long-term stability. Recent reports showed improved charge transport properties using diammonium cations in 2D Dion-Jacobson (DJ) MHPs, likely caused by decreasing the gap between the 2D MHPs with charge transport layers. Even more interestingly, broadband white light emission has been observed in (N-