The similarity in redox behavior between the polymers and bare PCT as well as thiophenesubstituted PCT derivatives provided some indication that the ability of the PCT units to become globally aromatic (cf. Scheme 1, top right) is not affected by the integration into the conjugated polymer backbone. To study the effect of neighboring PCT units on the redox behavior and on the local and global aromaticity in different charge and spin states in more detail, we computed the redox potentials and carried out nucleus-independent chemical shift (NICS) calculations for polymer fragments composed of two PCT units linked by either a thiophene (PCT-T-PCT, Figure ) or bithiophene unit (PCT-2T-PCT, Supporting Information section 10.3.2). The NICS tensors were then represented graphically using the visualization of chemical shielding tensors (VIST) method. The results of these computations on PCT-T-PCT, which consider the neutral ground state, the doublet monoanion, the singlet and triplet of the dianion, the doublet trianion as well as the singlet and triplet of the tetraanion, are presented and discussed here.