| Popis: |
Crystal structures of chloral 4-bromo-, 4-methyl-, 2,4-dichlorobenzylhemiacetals, and iso-butylhemiacetal were determined by the single crystal X-ray method at room temperature. Two modifications were found for the 2,4-dichlorobenzyl derivative. A chiral chain of molecules formed by OH … O hydrogen bonds (H-bonds) along a 21 axis is common to the crystals studied, except for iso-butyl derivative where a centrosymmetric dimer is formed by H-bonds. Conformation analyses were made using molecular mechanics. The crystal structures and IR spectra indicated that the H-bonds in these crystals except for the 2,4-dichlorobenzyl derivate were bifurcated ones. An intramolecular OH…Cl interaction was found in the iso-butyl derivative. The relationship between the 35Cl NQR spectrum and the molecular structure are discussed. |
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