2,2',5,5'-Tetracarboxy- and 2,2',5,5'-tetracarbamoyl-substituted biphenyls and also the 2,2',3,3',6,6'-hexacarboxy-substituted analogue behave as Siamese twins of terephthalic tectons in the single crystal self-assembly, giving rise to chiral 2D grid layers. A comparison has been made with the corresponding 2,2',6,6'-tetrasubstituted biphenyls which mimic isophthalic twins in their self-assembly.