Herein, we report the design and crystal growth of the network of K2H2mpba (1) [H4mpba = N,N′-1,3-phenylenebis(oxamic acid)], which exhibits the quite unusual (6,12)-connected alb topology. The characterization of 1 shows the following features: (i) the presence of deprotonated H2mpba2− moieties, (ii) thermal stability up to approximately 300 °C, and (iii) H2mpba2− acting as a 12-c molecular building block (MBB) and occupying the vertices of the double six-membered ring “d6R”. These rings combine with potassium ions, which fill the vertices of a trigonal prism. A discussion is provided on the role played by the type of metal centre (Mn+, M = Mn, Ni, Co, Cu) and countercation [tetrabutylammonium (TBA+) or tetraethylammonium (TEA+)] in a series of structurally characterized Mn+–H2mpba2− systems described in the literature.
