Reproducible Synthesis of a Monofluorinated Trimesate: A Versatile Linking Ligand for the Construction of Lanthanide Coordination Polymers

Abstract

Abstract. The synthesis of monofluorinated trimesic acid (H 3 mfBTC = 2-fluoro-1,3,5-benzene-tricarboxylic acid) described in the literature leads in fact to its monopotassium salt K(H 2 mfBTC) (1), which was identified by a single crystal structure analysis (Pc, Z = 2). It is obtained as a single-phase product and shows good solubility in water so that from aqueous solutions fourteen new coordination polymers with Ln III cations were synthesized and structurally characterized.

Two New MOFs Based on Cu2 Paddlewheel Units and Biphenyltetracarboxylate Ligands with a Different Degree of Fluorination

“…As described earlier fluorination of the phenyl rings in ortho position to the carboxylate group leads to an increased torsion angle between the latter and the plane of the phenyl ring due to repulsive interactions between the fluorine atom and the oxygen atoms of the carboxylate group and a reduced aromatic character of the C(phenyl)–COO – bond due to the electron withdrawing fluorine substituent , , . For UoC‐1(1F) this torsion angle was found to be 28.9(9)° and thus significantly larger than in HKUST‐1 and MOF‐505 (cp.…”

“…These angles are summarized in Table for UoC‐1(1F) and selected MOFs with a Cu 2 paddlewheel unit. For the enlarged torsion angles steric effects as well as electronic effects [reduced aromatic character of the C(phenyl)–COO – bond] are discussed , , . In CuMBTC and CuEBTC, methyl and ethyl groups, respectively, were introduced in ortho position to the carboxylate groups of a trimesate ligand .…”

“…In our own work we have concentrated on MOFs based on fluorinated linkers with the intention to investigate the influence of linker fluorination on the chemical and thermal stability of the MOF as well as its adsorption and luminescence properties. The interest in such MOFs with fluorinated linkers is increasing mainly due to their high hydrophobicity .…”

Two New Coordination Polymers with UO22+ Units and Fluorinated Aromatic Carboxylate Linkers

“…Several years ago we started to synthesize fluorinated aromatic carboxylic acids,, which – in a next step – were used to synthesize new CPs and MOFs with these linkers . With respect to their structural chemistry it is a remarkable feature that the torsion angle between the phenyl ring and the carboxylate group is no longer close to 0° as found in most MOFs and CPs with non‐fluorinated ligands, but significantly increased especially for fluoro substituents in α position and even more for perfluorinated ligands , .…”

Completing the Series: New Coordination Networks of Composition 3∞[RE2(ADC)3(H2O)6]·2H2O with RE = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Y and ADC2– = Acetylenedicarboxylate (–O2C–C≡C–CO2–)

“…Especially the Eu 3+ and Tb 3+ compounds are of interest, as strong luminescence is expected for coordination polymers of these RE 3+ cations . Furthermore, it is worthwhile to identify the limit of this structure type (CN = 9), as typically other structure types with smaller coordination numbers (CN) are found with decreasing radii of the RE 3+ cations …”