Solubilities of organic semiconductor compounds are of great importance in controlling the coating, crystallization, and phase-separation processes in the fabrication of organic thin-film devices. Here we measured the solubility of N,N′-di(1-naphthyl)-N,N′-diphenyl benzidine (NPB), a typical hole-transport material, in 23 organic solvents by UV absorption spectroscopy. The solubility of NPB in mole fraction unit x₂ ranged widely from 2.4 × 10^–7 in methanol to 2.8 × 10^–3 in chloroform. The solubility data was correlated with the Hansen solubility parameter (HSP) as a function of the solute–solvent distance R_a in the 3D HSP space. A least-squares regression to the equation −log x₂ = aR_a² + b, based on the Scatchard–Hildebrand regular solution theory, was carried out to determine the coefficients (a = 0.0102 MPa^–1 and b = 2.16) and the HSP of NPB (δ_D = 22.6 MPa^1/2, δ_P = 6.8 MPa^1/2, and δ_H = 5.8 MPa^1/2 for the dispersion, polarity, and hydrogen-bonding interactions, respectively). The correlation enabled us to describe the solvent dependence of the solubility of NPB within the root-mean-square deviation of 0.47 in log x₂ from the experimental data.

中文翻译：

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的溶解度Ñ，Ñ ' -二（1-萘基） - ñ，ñ '在各种有机溶剂-二苯基联苯胺（NPB）：测定与关联与Hansen溶解度参数

有机半导体化合物的溶解度在控制有机薄膜器件制造中的涂层，结晶和相分离过程中非常重要。在这里，我们通过紫外吸收光谱法测量了一种典型的空穴传输材料N，N'-二（1-萘基）-N，N'-二苯基联苯胺（NPB）在23种有机溶剂中的溶解度。NPB的摩尔分数单位x ₂的溶解度范围从甲醇中的2.4×10 ^–7到氯仿中的2.8×10 ^–3。溶解度数据与Hansen溶解度参数（HSP）相关，该参数是溶质-溶剂距离R _a的函数在3D HSP空间中。根据Scatchard–Hildebrand正解理论，对方程-log x ₂ = a R _a ² + b进行了最小二乘回归，以确定系数（a = 0.0102 MPa ^–1和b = 2.16），并且NPB的HSP（δ _d = 22.6兆帕^1/2，δ _P = 6.8兆帕^1/2，和δ _ħ = 5.8兆帕^1/2分别用于分散，极性和氢键相互作用）。相关性使我们能够描述NPB溶解度的溶剂依赖性，从实验数据得出log x ₂的均方根偏差为0.47 。