Pyridyl-substituted oxalamides, L1 (4-pyCH2NHCOCONHCH2py-4), L2 (3-pyCH2NHCOCONHCH2py-3), and L3 (2-pyCH2NHCOCONHCH2py-2), with HgI2 and/or CuBr2, form three new supramolecular complexes, [Hg3L1I6]∞ (1), {[Cu2(L2)4Br2]·Br2·4H2O}∞ (2), and [Hg(L3)2I2]∞ (3), respectively. The complexes 1−3 are aligned by the oxalamide−oxalamide N−H···O hydrogen bonds between layers, and their crystal structures have been determined by single-crystal X-ray diffraction. Complex 1 forms a two-dimensional (2D) zigzag sheet architecture extending along the c-direction bridged by L1 ligand and HgI2. Complex 2 forms an interesting planar 2D (4,4) network with the uncoordinated Br− anions and H2O molecules located in the cavities. Complex 3 forms [2 + 2] metallomacrocycles, which are linked with the μ2-bridged I atom and stacked together by intermolecular oxalamide−oxalamide hydrogen bonds and by edge-to-face π-stacking between the pyridyl rings to form the desired supramolecular tubular structure along the a-axis. After the removal of the solvent molecules, solid 2 exhibits a permanent porosity verified by a N2 sorption isotherm with a N2 uptake of approximately 1258 cm3/g (STP) and a Langmuir surface area of 2102 m2/g.