1H and 19F shielding and deuteron EFG tensors in tetrafluoroterephthalic acid. NMR and neutron-scattering determination of crystal structure

Optimized Synthesis of Tetrafluoroterephthalic Acid: A Versatile Linking Ligand for the Construction of New Coordination Polymers and Metal-Organic Frameworks

“…Compound 1 crystallizes in the triclinic space group P 1̅ as colorless blocks from acetone. The unit cell constants are quite similar to those previously reported in X-ray and neutron diffraction studies of the deuterated derivative, which have been performed at room temperature . The molecular structure of 1 (Figure ) is almost identical to the reported structures from these studies, although slight deviations occur.…”

“…The unit cell constants are quite similar to those previously reported in X-ray and neutron diffraction studies of the deuterated derivative, which have been performed at room temperature. ( 30 ) The molecular structure of 1 (Figure 1 ) is almost identical to the reported structures from these studies, although slight deviations occur. For instance, the plane of the carboxylate group is twisted by 19.3(1)° around the bond C1−C7 out of the least-squares plane of the aryl ring, which is slightly smaller than reported for the structure of the perdeuterated acid (19.8(1)°).…”

“…The packing of the structures of 1 and its deuterated congener reveal, however, significant differences. ( 30 ) In different layers the infinite chains are arranged in a way that the carboxylate groups are above and below the aryl rings of the neighboring layers for 1 , while in the deuterated variety the aryl rings are stacked above each other. In 1 the planes of the aryl rings of different layers are related by translation along the crystallographic a -axis showing a distance C3−C3′ of 3.294(2) Å, which is significantly shorter than in its perdeuterated analogue (3.377 Å).…”

17O NMR evidence for 180°-flips of (COOH)2units in dimethylmalonic acid

“…The dynamics of hydrogens, i.e., protons or deuterons in hydrogen bonds (H-bonds) is currently a subject of active research [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These hydrogens are usually supposed to move in a double well potential with the reaction coordinate along the line connecting the bonded heavy atoms, O, N, CI, etc., as the case may be.…”

“…The hydrogens in dimeric H-bonds have been shown by measurements and analyses of the H-H dipole-dipole coupling tensors to carry out their jumps along the H-bonds in a concerted manner [3,5,9]. This is schematized in figure !…”