Figure 32
D,L-Homocysteine thiolactone hydrochloride: there is a clear difference between the projections of the Pbca and Pbc21 phases down [010], while those down [100] (not shown) are barely distinguishable. The O, N ends of adjacent molecules are staggered on opposite sides of the a glide plane in HTL-Pbca, while they are directly opposed in HTL-Pbc21. The chloride ions are the large darkened partially obscured circles. Adapted from Freer & Kraut (1965). |