Fig. 71. Examining theoretical dye structures. (A) Structure diagram for dye 17 and 28 from the work of Jacquemin.⁴⁷⁷ Light grey – hydrogen, dark grey – carbon, dark blue – nitrogen, green – chlorine, red – oxygen. Calculations on these structures were performed to obtain the magnitude and direction of Δd_m and μ_m. (B) Signal amplitude schematic of a dimer with hopping time, τ_h (“beat time” between the two exciton states) & dephasing time τ_d. J_m,n of 98 meV (790 cm⁻¹) gives ω_h ∼ 47 THz²²² (eqn (23)) or τ_h of 21 fs. A τ_d ∼ 54 fs is obtain from the reduction of homogeneous broadening of ΔE_homog ∼ 18 THz observed in a DNA template rotaxane SQ dimer.⁴⁰³ Assuming 5% of measurable original signal amplitude (i.e., e^{(−t/[3×τ_d])}) gives 3τ_d or 162 fs (time to be able to perform measureable calculations) & n > 7 measurable gate operations. T = 295 K.