A small series of partially alkylated bisindolylmaleimide dyes were prepared containing NO2 groups at the ortho, meta, and para position. The effect of substitution position in the aryl ring on the photophysical properties of the dyes is discussed in detail. The highly electron withdrawing NO2 makes different emission behavior of these dyes. Medium quantum yields of fluorescence in toluene solution are observed for derivative with NO2 substituted in the ortho position of aryl ring. Careful analysis of optimized structure and frontier molecular orbitals (HOMO/LUMO) suggests that the electronic rather than steric effect is controlling non-radiative decay.