Within a series of α,α′-diferrocenylthiophenes, the influence of electron-withdrawing substituents at the ferrocenyl moieties and electron-donating functionalities at the thiophene bridge on the electronic behavior was studied. The synthesis of the appropriate 2,5-fc₂-^cC₄H₂S and 2,5-fc₂-3,4-(OCH₂CH₂O)-^cC₄S compounds (fc = Fe(η⁵-C₅H₄)(η⁵-C₅H₄R); R = H (1, 5), 3,5-(CF₃)₂-cC₆H₃ (2, 6), CHO (3, 7), C≡N (4, 8)) was carried out using the Negishi C,C cross-coupling protocol to effect the coupling of the thiophene and the ferrocenyl moieties. The corresponding diferrocenylthiophenes were characterized spectroscopically. Within this context, the structural properties of 2-5, [5][B(C₆F₅)₄], 6, and 8 in the solid state were investigated by single-crystal X-ray diffraction studies. Electrochemical investigations of thiophenes 2-8 demonstrated an increasing redox separation and hence thermodynamic stability of the corresponding mixed-valent species in the series 1 < 3 < 5 < 4 ≈ 2 < 6 < 7 < 8. Moreover, UV/vis/near-IR and infrared spectroelectrochemical studies verify these observations. These studies further reveal a valence trapped situation in corresponding mixed-valent species and allow a class II classification according to Robin and Day.