The methyl orange [C₁₄H₁₄N₃SO₃Na], an azo dye exhibited strong emission and large Stokes shift in various solvents, and the largest shift (Δλ = 125.51nm or Δν = 9297cm^-1) was obtained in the water. The UV-visible spectra of the dye showed the absorption in the range (33,333 – 20,000) cm^-1. We found that solvent effects on the absorption wavelength are consistent. The bathochromic shift in water and the hypsochromic shift in methanol observed in the absorption (43 nm) as well as in the fluorescence (42 nm) spectra predict the strong solute-solvent interaction. The fluorescence quantum yield (ɸ_f) was decreased from 24% in DMSO to 5% in water. The fluorescent properties of this dye are strongly solvent dependent, the wavelength of minimum fluorescence emission (λ_em = 435.51nm) shifts to the red. The maximum and minimum calculated oscillator strength is 32% with (Ɛ_max = 29011 M^-1cm^-1) and 11% (Ɛ_max = 6682 M^-1cm^-1) in methanol and DMSO, respectively. Protonated solvents without exception give a shorter lifetime and lower quantum yield. The average excited-state lifetime of the dye was found maximum (τ_av = 5.36 ns) in DMSO. Also, fluorescence lifetime was combined to deduce the radiative and non-radiative decay rate.

甲基橙[C ₁₄ H ₁₄ N ₃ SO ₃ Na]，一种偶氮染料，在各种溶剂中表现出强发射和大斯托克斯位移，在水中获得最大位移（Δλ = 125.51nm 或Δν = 9297cm ^-1） . 染料的紫外-可见光谱显示在 (33,333 – 20,000) cm ^-1范围内的吸收。我们发现溶剂对吸收波长的影响是一致的。在吸收 (43 nm) 和荧光 (42 nm) 光谱中观察到的水中红移和甲醇中的减色移预示着强烈的溶质-溶剂相互作用。荧光量子产率 (ɸ _f) 从 DMSO 中的 24% 减少到水中的 5%。这种染料的荧光特性强烈依赖于溶剂，最小荧光发射波长 (λ _em = 435.51nm) 向红色移动。在甲醇和 DMSO 中，最大和最小计算的振荡器强度分别为 32%（Ɛ _max = 29011 M ^-1 cm ^-1）和 11%（Ɛ _max = 6682 M ^-1 cm ^-1）。质子化溶剂无一例外地提供更短的寿命和更低的量子产率。发现染料的平均激发态寿命在 DMSO 中达到最大值 (τ _av = 5.36 ns)。此外，结合荧光寿命来推断辐射和非辐射衰减率。