in polymers
Also contains definition of: enantiomorphous structures in polymers
https://doi.org/10.1351/goldbook.I03299
In the crystalline state, polymer chains are generally parallel to one another but neighbouring chains of equivalent , the first atom of the . For certain chain symmetries (helical, for instance) the bond vectors have the same components (positive or negative) along the c axis for every .
Two equivalent (isomorphous or enantiomorphous) chains in the crystal lattice, having identical components of the bond vectors along c, both positive or both negative, are designated isoclined; two equivalent chains having bond vectors along c of the same magnitude but opposite sign are designated anticlined.
conformation
may differ in chirality
and/or orientation. Chains of identical chirality
and conformation
are isomorphous. Chains of opposite chirality
but equivalent conformation
are enantiomorphous. For example, two ...TG+TG+TG+... helices of isotactic poly(propylene) are isomorphous. Isotactic poly(propylene) chains of the ...TG+TG+TG+... and ...G−TG−TG−T... types are mutually enantiomorphous. With regard to orientation, consider a repeating side group
originating at atom side group
being ![Not defined](/img/inline/I03299.png)