Crystal structure of (E)-undec-2-enoic acid

Crystal and mol-ecular structure of meso-2,6-di-bromo-hepta-nedioic acid (meso-2,6-di-bromo-pimelic acid)

The mol-ecular structure of the title compound, C7H10Br2O4, confirms the meso (2R,6S) configuration. In the crystal, mol-ecules are linked by pairs of O-H⋯O=C hydrogen bonds between their terminal carboxyl groups in an R 2 (2)(8) motif, forming extended chains that propagate parallel to the c axis. Adjacent chains are linked by C=O⋯Br halogen bonds.

Crystal structure of (E)-dodec-2-enoic acid

The crystal structure of (E)-dodec-2-enoic acid, C12H22O2, an α,β-unsaturated carb-oxy-lic acid with a melting point (295 K) near room temperature, is characterized by carb-oxy-lic acid inversion dimers linked by pairs of O-H⋯O hydrogen bonds. The carb-oxy-lic acid group and the following three carbon atoms of the chain of the (E)-dodec-2-enoic acid mol-ecule lie almost in one plane (r.m.s. deviation for the four C atoms and two O atoms = 0.012 Å), whereas the remaining carbon atoms of the hydro-carbon chain adopt a nearly fully staggered conformation [moduli of torsion angles vary from 174.01 (13) to 179.97 (13)°].