Abstract: Biphenyl compounds have potential applications in coordination chemistry, bioinorganic chemistry, materials and medicine. A new biphenyl compound(biphenyl-2,2'-dicarboxylic acid-2-methyl ester) was synthesized by refluxing biphenyl-2,2'-dicarboxylic acid with Ln(ClO₄)₃·6H₂O in the mixed-solvent of methanol and water for 5 h. The crystals were characterized by X-ray single crystal diffraction, elemental analysis, IR, and ¹H NMR. It belongs to monoclinic system with space group P2₁/n and cell parameters a=1.237 7(5) nm, b=0.808 2(3) nm, c=1.404 8(6) nm, β=114.410(6)° and Z=2. The strong intermolecular hydrogen bonds observed leads to a centrosymmetric dimmer. The oxygen atoms of carboxylic groups in the title compound have strong coordination abilities. It can perhaps be employed to aggregate with transitional metal atoms or lanthanide atoms and generate new complexes, which may have potential applications in many fields. To the best of our knowledge, the synthesis, structure and characterization of biphenyl-2,2'-dicarboxylic acid-2-methyl ester were first reported.

Key words: Biphenyl compound, Synthesis, Crystal structure