An isoreticular series of two-dimensional MOFs was synthesized using Zr12 clusters and linear ligands with different length scales, namely NDC, BPDC, and AZDC (Figure ). The hexagonal Zr-based clusters led to a triangular lattice with hxl topology when projecting the MOF structure along the c-axis. The respective MOFs, denoted as Zr-NDC, Zr-BPDC, and Zr-AZDC, successfully enabled us to achieve precise and systematic control over the lattice size. The triangular lattices were observed by TEM, revealing inter-cluster distances of 1.7, 1.9, and 2.1 nm for Zr-NDC, Zr-BPDC, and Zr-AZDC, respectively (Figures and). These values were also in excellent accordance with the corresponding cell parameters calculated from Powder X-ray diffraction (PXRD) patterns (Figure ). The PXRD patterns primarily showed (hk0) reflections, confirming the two-dimensional structures. The Zr-MOFs exhibited hexagonal nanosheets with thickness ranging from 1.7 to 20 nm, as confirmed by SEM and AFM images (Figures and). The monolayer thickness of 1.7 nm aligns with the height of the Zr12 cluster. The porosity of Zr-NDC, Zr-BPDC, and Zr-AZDC was examined by N2 adsorption isotherms at 77K, revealing uptakes of 487, 362, and 226 cm 3 /g with corresponding Brunauer-Emmett-Teller (BET) surface areas of 741, 1101, and 762 m 2 /g, respectively (Figure ). After the adsorption measurement, the structural integrity of the MOFs was preserved, as demonstrated by PXRD patterns (Figure ).