The solubilities of decahydropyrazino[2,3-b]pyrazine (DHPP) in methanol, ethanol, and 2-propanol were measured at temperatures ranging from 274.95 to 354.75 K. The last crystal disappearance method was used to determine the solubility of DHPP. The experimental data were correlated by the van’t Hoff plot, λh (Buchowski) equation, modified Apelblat equation, and two local composition models (Wilson and NRTL). Moreover, the densities of (DHPP + water) solution were measured from 274.25 to 355.95 K, and the liquid molar volume of DHPP, V_m1(T), was obtained and used to calculate the parameters in the Wilson model. It was found that NRTL model gave the best correlation results. On the basis of the NRTL model and experimental data, the thermodynamic excess functions (ΔG_E, ΔS_E, and ΔH_E) of DHPP + alcohols (methanol, ethanol, and 2-propanol) systems were determined. Furthermore, the infinite-dilution activity coefficient and the infinite-dilution reduced excess enthalpy (γ₁^∞ and ΔH_E1^∞) were derived.

中文翻译：

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十氢吡嗪并[2,3-b]吡嗪在甲醇，乙醇和2-丙醇中的溶解度的测定及相关性

在274.95至354.75 K的温度范围内测量十氢吡嗪并[2,3-b]吡嗪（DHPP）在甲醇，乙醇和2-丙醇中的溶解度。最后一种晶体消失法用于确定DHPP的溶解度。对实验数据进行由范特霍夫情节相关，λ ħ（Buchowski）方程，修正Apelblat方程，以及两个局部组成模型（Wilson和NRTL）。此外，测量（DHPP +水溶液）的密度为274.25至355.95 K，DHPP的液体摩尔体积V _m1（T），然后将其用于计算Wilson模型中的参数。发现NRTL模型给出了最好的相关结果。根据NRTL模型和实验数据，确定了DHPP +醇（甲醇，乙醇和2-丙醇）系统的热力学过剩函数（ΔG _E，ΔS _E和ΔH _E）。此外，无限稀释活度系数和无限稀释减少过量焓（γ ₁ ^∞和Δ ħ _E1 ^∞）而得。