The electronic effects of varying the nature of the carbonyl groups in a series of perylene-3,4,9,10-tetracarbonyl compounds have been investigated. The four carbonyl groups comprise of esters, imides and anhydrides and combinations thereof. The series has been extensively characterised by electrochemical methods and it is found that the combination of imide and anhydride groups enhances the electron accepting properties of the perylene core. In contrast, the perylene core is the most electron rich when each of the four peri-positions is functionalised with an ester group. In the case of tetra-esterified perylene a reversible oxidation process can also be observed. The nature of the carbonyl species provides a degree of redox potential tunability whilst maintaining similar optical properties of the chromophores. This suggests that careful selection of peri-substituents is important in the fabrication of optoelectronic devices incorporating 3,4,9,10-tetracarbonyl perylene species.