The structures of single crystals of syndiotactic poly(butene-1) in form I,
produced by thin-film growth, are studied by transmission electron microsc
opy and electron diffraction. Bright-field electron microscopy observation
shows that the single crystal exhibits a regular rectangular shape with the
long axis along its crystallographic b-axis. Electron diffraction results
indicate an isochiral C-centered packing of a-fold helical chains in an ort
horhombic unit cell corresponding to the C222(1) space group, according to
the model proposed in the literature. The differences with the polymorphic
behavior of syndiotactic polypropylene concerning the formation and the sta
bility of the isochiral mode of packing are outlined.