3,5-Diphosphonobenzoic Acid, a New Rigid Heterotrifunctional Building Block to Design Metal Organic Frameworks. Illustration with the Characterization of Cu 5 [(O 3 P) 2 -C 6 H 3 -CO 2 ] 2 (H 2 O) 6

The synthesis of 1,3-diphophonobenzoic acid (H5L2), a rigid precursor belonging to the family of 1,3,5-trisubstituted benzene compounds, is reported following a straightforward two-step sequence. The new rigid hetero-trifunctional building block has been engaged with Cu(NO3)2·3H2O in hydrothermal synthesis to produce a new metal−organic framework (MOF) Cu5[L2]2(H2O)6 (3). The structure of compound 3 has been solved by X-ray diffraction on single crystal and can be described as inorganic columns running along the c axis and separated by the organic parts. Magnetic measurements have been performed in order to evaluate the magnetic behavior and the moments of the Cu2+ ions in this structure.