Adjective
English Wikipedia has an article on:syndiotacticWikipedia
syndiotactic (not comparable)
(chemistry, of a polymer) Having substituents arranged in alternating (rather than random) configuration in each repeat unit.
Both isotactic and syndiotactic polypropylene are crystalline, whereas atactic polypropylene, which can also be prepared with special Ziegler–Natta catalysts, is amorphous. Source: Internet
Short segments of polypropylene, showing examples of isotactic (above) and syndiotactic (below) tacticity The concept of stereoregularity in polymer chains is illustrated in the picture on the left with polypropylene. Source: Internet
If a special catalyst is used in its synthesis it is possible to obtain the syndiotactic version of this polymer, but most industrial polystyrene produced is atactic. Source: Internet
There are three types: isotactic (all substituents on the same side), atactic (random placement of substituents), and syndiotactic (alternating placement of substituents). Source: Internet
The result is that, whereas syndiotactic PS is a semicrystalline material, the more common atactic version cannot crystallize and forms a glass instead. Source: Internet