Two-dimensional metal-organic layers constructed from Hf 6 /Hf 12 -oxo clusters and a trigonal pyramidal phosphine oxide ligand.

Metal-organic layers (MOLs), a category of two-dimensional materials, have attracted wide interest due to their molecular tunability and the ease of surface modification. Herein, we reported the synthesis and structural determination of a free-standing MOL, {[Hf 6 O 8 H 4 (HCOO) 2 (H 2 O·OH) 4 ] 3 [Hf 12 O 16 H 8 (HCOO) 6.8 (H 2 O·OH) 11.2 ](TPO) 8 } n , constructed from Hf 6 -oxo and Hf 12 -oxo clusters as secondary building units (SBUs) and the tris(4-carboxylphenyl)phosphine oxide (TPO) ligand. We establish a structure model of this new MOL based on the combined information from different characterization methods.