This research provides a clear structure-property relationship that guides the rational design of functional antiaromatic materials with tunable electronic properties. Although we were unable to isolate the sterically demanding 2,6-dichlorophenyl derivative (1d) which combines strong antiaromaticity with sufficient stability, our results revealed strategies for balancing these competing properties. These insights contribute to the growing field of antiaromatic material design for potential applications in organic electronics and optoelectronic devices. Future work will focus on developing isophlorin derivatives that maintain strong antiaromaticity through appropriate substituent orientation while achieving sufficient stability through electron-withdrawing effects without compromising macrocycle planarity.