Backbone group definition
Backbone group. , unless stated otherwise, means the group/groups that has/have the highest content of all groups present in a polymer, preferably with a ratio > 20%, very preferably > 30%, in particular > 40%, most preferably > 50%. Backbone groups can also form electron transporting units, hole transporting units, exciton formation units or emissive units either alone or in combination with other groups. For example, if there are two groups whose contents are clearly higher than those of the other groups present in the polymer, or if there are only two groups present in a polymer, then both groups are considered as backbone groups. Preferably the backbone groups are hole transporting groups or electron transporting groups.