APPLICATION OF WALLACHS RULE IN A COMPARISON OF THE X-RAY CRYSTAL-STRUCTURES OF THE RACEMATE AND THE (S) ENANTIOMER OF (1-HYDROXY-3-PHENYL-2-PROPENYL) DIMETHYLPHOSPHONATE

The crystal structures of the racemate and the (S) enantiomer of (1-yd roxy-3-phenyl-2-propenyl) dimethylphosphonate, C11H15O4P, were determi ned by X-ray diffraction. The crystal density of the racemate was foun d to be 6.2% greater than the crystal density of the (S) enantiomer. I n both crystal structures the molecules form chains by hydrogen bondin g between the OH of one molecule and the P double bond O of another. O bserved differences in atomic displacement between the two structures are discussed in view of the C-H ... O interactions.