Pioneered by Fujita and coworkers, this approach involves the assimilation of square planar complexes with a 90° angle achieved by blocking two of the coordination sites with another cis-coordinating ligand (e.g. ethylenediamine) and 2D panels (e.g. triangles, squares, and pentagons) representing the organic ligands (Figure ).for example, a tetrahedron can be designed by stitching together four triangular panel, while an octahedron can be generated by bringing together eight such triangular panels (Figure ).