Synthesis and Structural Characterization of Lithium-Based Metal−Organic Frameworks

Two lithium-based metal−organic frameworks, Li2(C14H8O4) [Li2(4,4′-BPDC) [1]; ULMOF-2, UL = ultralight; BPDC = biphenyldicarboxylate]; space group P21/c, a = 12.758(2) Å, b = 5.142(4) Å, c = 8.00(2) Å, β = 97.23°, V = 520.6(14) Å3 and Li2(C14H8O6S) [Li2(4,4′-SDB) [2]; ULMOF-3, UL = ultralight; SDB = sulfonyldibenzoate], space group P21/n, a = 5.5480(11) Å, b = 23.450(5) Å, c = 10.320(2) Å, β = 96.47(3)°, V = 1334.1(5) Å3, were synthesized. Compounds 1 and 2 were synthesized by solvothermal methods and were characterized using single crystal X-ray diffraction. Structure 1 consists of layers of two-dimensional antifluorite related LiO motif connected by BPDC linkers, whereas structure 2 is constructed by a combination of tetrameric lithium polyhedral clusters connected by the sulfonyldibenzoate linker. The frameworks are stable up to 575 and 500 °C, respectively, under N2 atmosphere.