Coordination Polymers with Tetrafluoroterephthalate as Bridging Ligand

Abstract

Seven nonporous coordination polymers with tetrafluoroterephthalate (tfBDC 2À ) as a bridging ligand were synthesized and structurally characterized. Homoleptic ∞ 3 [Tl 2 (tfBDC)] (P1, Z = 1, 1) contains six-coordinated Tl centers, which are connected by the tfBDC 2À ligand to form a three-dimensional (3D) network. Upon heating it decomposes at approximately 200 °C. Nine-coordinated PbO 9 polyhedra are found in ∞ 2 [Pb(tfBDC)(H 2 O) 3 ] 3 1/2 H 2 O (P1, Z = 1, 2), which forms a layer-like structure. These layers are held together by hydrogen bonds involving water molecules. These water molecules are released by heating to 70À100 °C. ∞ 1 [M II (tfBDC)(H 2 O) 4 ] (P1, Z = 1; M II = Zn (3), Co (4), Ni (5)) contains almost undistorted M II O 6 octahedra with the carboxylate groups of the tfBDC ligands in trans coordination so that a chain-like structural unit is formed. These chains are further connected by hydrogen bonds. Upon heating, these water molecules are released in two steps at 100 and 200 °C. ∞ 3 [Mn 2 (tfBDC) 2 (DMF) 2 (EtOH)] (P2 1 , Z = 2, 7) is isostructural to the known Zn compound (6). Both compounds contain dimeric [M II O 6 ] 2 units, which are connected by tfBDC 2À ligands to form a 3D network.All compounds are unprecedented in the crystal chemistry of coordination polymers with nonfluorinated terephthalate (BDC 2À ) as bridging ligand. This is mainly because the planar conformation found for BDC 2À is energetically less favorable for perfluorinated tfBDC 2À .

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

“…These torsion angles are surprising, as the occupancy of F2 was refined to a higher value (65 %) than that of F3 (35 %). Nevertheless, a higher torsion angle is observed with F3 in α position, which is different to most reports in the literature , . In our former work with the monofluorinated 4‐ mF ‐BPTC 4– linker we found a torsion angle of 28.9(9)°, which is significantly larger than those found for anion A in this work.…”

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

“…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 .…”

Two Anhydrous Salts of Tetrafluoroterephthalic Acid (H2tF‐­BDC): K2tF‐BDC and Rb2tF‐BDC

“…Details are given in the Experimental Section. 2 crystallizes in a structure type that was found earlier for Tl 2 tF‐BDC ( P $\bar{1}$ , Z = 1) 8. Selected crystallographic and refinement data are given in Table 2, some interatomic distances and angles are listed in Table 3.…”