T D 1Q4 ili 2 bi 3 K 4Q1 5 of Ch 6 7 8 9 10 11 12 131415 16 Keywords: 17 6-Chloro-3-aminopyridazine 18 19 20 21 22min 23syn 24ing 25emp 26dat 27activity coefficients and molar enthalpy of dissolution 6-chloro-3-aminopyridazine were obtained. 28© 2013 Published by Elsevier B.V. 2930 31 32 33 34 lN3, CA 35 ate for 36 porin [1 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64lpy of fusion ΔHfus of 65by DSC (differential Journal of Molecular Liquids xxx (2013) xxx–xxx MOLLIQ-03936; No of Pages 6 Contents lists available at ScienceDirect Journal of Mole .e ls U Naminopyridazine in solvents at different temperatures is importantfor optimizing the crystallization process. However, the solubility dataof 6-chloro-3-aminopyridazine in water and (water + ethanol) binary mixtures are not available in the previous publications [5]. In this work, the solubility of 6-chloro-3-aminopyridazine in water and (water + ethanol) binary mixtures was measured from 293.15 to resistivity N 5 MΩ ⋅ cm) was used throughout. 2.2. Fusion property measurements The fusion point temperature Tfus and entha 6-chloro-3-aminopyridazine were obtained C Othe death of the larvae [2–4].In industry, the pure 6-chloro-3-aminopyridazine is mainly purified by crystallization and further recrystallization from the solvents such as water, ethanol or mixtures of those [4]. The solubility of 6-chloro-3- fied sample was analyzed by HPLC (type Shimadzu LC-10AT, Japan), and determined to be more than 0.995. The ethanol used in our exper- iments is analytical reagent grade, and provided by Tianjin Kewei Chemical Reagent Co., Ltd., China. Redistilled deionized water (specific 338.15 K at atmospheric pressure. Themodified and polynomial empirical equationswere chose solid–liquid equilibrium data. The activity coeffi of dissolution of 6-chloro-3-aminopyridazine w ⁎ Tel.: +86 539 8766300; fax: +86 539 8766600. E-mail address:
[email protected]. 0167-7322/$ – see front matter © 2013 Published by Else http://dx.doi.org/10.1016/j.molliq.2013.08.013 Please cite this article as: L. Wang, J. Mol. Liq. ( R]. It is also a useful inter-s which can exhibit larvi- f insect larva, and lead to 6-Chloro-3-aminopyridazine (mass fraction purity N 0.98) supplied by Tongchuang Pharma Co., Ltd., China was purified by recrystallization from an (ethanol + water) mixture. The mass fraction purity of puri- mediate for synthesizing benzoylpyridazyl urea cidal activities against the generation of chitin o Solid–liquid equilibrium 1. Introduction 6-Chloro-3-aminopyridazine (C4H4C is a very important organic intermedi which is the fourth generation cephalos R E C S Registry No. 5469-69-2) synthesizing Cefozopran 2. Experimental 2.1. Materials Synthetic method E SolubilityModel Measurement and correlation of the solub 6-chloro-3-aminopyridazine in water and water + ethanol from 293.55 K to 342.95 Lei Wang ⁎ School of Chemistry & Chemical Engineering, Linyi University, Linyi 276005, People's Republic a b s t r a c ta r t i c l e i n f o Article history: Received 17 April 2013 Received in revised form 26 August 2013 Accepted 27 August 2013 Available online xxxx The solubility of 6-chloro-3-a 293.55 K to 342.95 K using a mined by differential scann Apelblat, λh and polynomial ment with all experimental j ourna l homepage: www Apelblat, λh (Buchowski) n to regress themeasured cients andmolar enthalpy ere estimated. vier B.V. 2013), http://dx.doi.org/10.10 P R O O F ina opyridazine inwater and (water + ethanol) binary systemwasmeasured from theticmethod. The fusion point temperature and enthalpy of fusionwere deter- calorimetry. The experimental solubility data were regressed by modified irical equations. Apelblat and empirical polynomial equations are in good agree- a with the root-mean-square deviation being less than 1.69%. In addition, the ty of nary mixtures of cular Liquids ev ie r .com/ locate /mol l iq 66scanning calorimetry) (Pyris-Diamond DSC, PerkinElmer, USA). The 67pre-calibration of the instrument was made by indium and tin (Tin: 68Tfus is 505.10 K, ΔHfus is 60.21 J g−1. Indium: Tfus is 429.75 K, ΔHfus is 6928.45 J g−1.) before the equipment was used. About 5 mg of 6-chloro- 703-aminopyridazine crystalline powder was added to an aluminum cru- 71cible of DSC. And then the sample was heated under a nitrogen atmo- 72sphere at a heating rate of 2 K/min from 473.15 to 513.15 K. The DSC 73peak integration was achieved using Origin's Peak Analyzer. The DSC 16/j.molliq.2013.08.013 T 74 experiments were repeated three times. The deviation in the tempera- 75 ture is ±0.5 K and in the enthalpy of fusion is no more than 1%. 76 2.3. Solubility measurements 77 The solubility of 6-chloro-3-aminopyridazine was determined by a 78 synthetic method [5–8]. The experimental procedure was described in 79 a previous publication [5], and was slightly improved in this experi- 80 ment, as shown in Fig. 1. 81 All experiments ofmeasuring solubilitywere carried out in a 200 mL 82 jacketed glass vessel. In order to prevent solvent evaporation, a con- 83 denser was linked directly to the vessel. At the outset of each experi- 84 ment, a predetermined mass of 6-chloro-3-aminopyridazine and 85 solvent were weighed on a precision electronic balance (type Sartorius 86 BS210S, Germany)with an uncertainty of±0.0001 g and thenwere put 87 into the vessel. The mixture was heated slowly by the water circulating 88 via the outer jacket provided by a thermostatically water bath (type 89 CS501, China) to a fixed temperaturewith continuous stirring by amag- 90 netic stirrer (type 85-2, China). A mercury-in-glass thermometer (type 91 92 93 94 95 96 97 98 99 100 101 102 103 and the relative uncertainties of measurements were below 1 mol%. 104 105 106 107 108 109 110111 112 113 114 115 116 117 118 119120 121 122 123 124 125 ln 1þ λ 1−x1ð Þ x1 ¼ λh 1 T − 1 T fus ð3Þ 126127where Tfus is the fusion point temperature of solid solute, and λ and h 128are the two constants. 1293.2.3. Polynomial empirical equation 130When the variable factors such as solute, solvent and pressure are 131defined, the solubility will change only when temperature changes. 132So the solubility of solute in solvents can be described by a 4th-order 133polynomial equation of absolute temperature as follows [15–17]: x1 ¼ aþ bT þ cT2 þ dT3 þ eT4 ð4Þ 134135where a, b, c, d, and e are adjustable equation parameters. 1363.3. Solubility data of 6-chloro-3-aminopyridazine 137The solubility data of 6-chloro-3-aminopyridazine in water and 138(water + ethanol) binary mixtures at different temperatures are 139reported in Table 1 and shown in Fig. 3. It can be seen that whether in 140water or in (water + ethanol) binary mixtures, the solubility of 6- 2 L. Wang / Journal of Molecular Liquids xxx (2013) xxx–xxx Fig. 1. Sketch of the experimental determinator for solubility: A, jacketed glass vessel; B, constant pressure funnel; C, mercurial thermometer transistor; D, condensation pipe; E, magnetic stirring apparatus; F, thermostat water bath; G, laser generator; U N C O R R E C3. Results and discussion3.1. Property evaluation of pure components The DSC of 6-chloro-3-aminopyridazine is shown in Fig. 2. The fusion point temperature Tfus and enthalpy of fusion ΔHfus are 493.9 ± 0.5 K[lit. (495.15–496.15) K[9]], and 36.3 ± 0.4 kJ/mol, re- spectively. Using the property of classical thermodynamics: ΔSfus ¼ ΔHfus=T fus ð1Þ WLB, China) with uncertainty of ±0.05 K was used to measure the temperatures of the solid–liquid mixture. Equilibrium points of 6- chloro-3-aminopyridazine were examined by a laser beam penetrating the glass vessel. When solid particles of 6-chloro-3-aminopyridazine just disappeared, the intensity of the laser beam penetrating the glass vessel reached a maximum, an additional 6-chloro-3-aminopyridazine [(2 to 5) mg] was added into the vessel. Repeating the process, until the last addition caused the light intensity being less than 90% of the maximum in 60 min, the mixture was considered as reaching phase equilibrium. The total amount of 6-chloro-3-aminopyridazine added was then recorded. All the solubility data points were determined three or more times, H, photoelectric converter; I, control and digital display. Please cite this article as: L. Wang, J. Mol. Liq. (2013), http://dx.doi.org/10.10 E D P R O O F the entropy of fusion ΔSfus of 6-chloro-3-aminopyridazine is obtained, and its value is 73.45 J/(mol·K). 3.2. Thermodynamic models 3.2.1. Modified Apelblat equation The absolute temperature T dependence of the experimental solubil- ity x1 of 6-chloro-3-aminopyridazine in water and the binary mixtures of water + ethanol can be well correlated by the modified Apelblat equation [10–12]: lnx1 ¼ Aþ B T þ ClnT ð2Þ where A, B and C are adjustable empirical constants. 3.2.2. λh (Buchowski) equation Buchowski et al. [13,14] used the λh (Buchowski) equation original- ly to describe the solubility of solid solute in liquid–solid phase equilib- rium systems. The model has an excellent effect for correlating the temperature and the solubility. The λh equation is given as: � � � � Fig. 2. DSC curve of 6-chloro-3-aminopyridazine. 141chloro-3-aminopyridazine increases with the rise of temperature. At 16/j.molliq.2013.08.013 U N C O R R E C TE D P R O O F Table 1t1:1 t1:2 Solubility x1, activity coefficientsγ1 of 6-chloro-3-aminopyridazine inpurewater and binarymixtures ofwater + ethanol, and the relative deviationsRDs of experimental solubility values t1:3 with the calculated results. t1:4 T/K 103x1 103xApel 102RDApel 103xλhQ2 102RDλh 103xPE 102RDPE γ1 t1:5 w = 0 t1:6 293.65 0.0628 0.0622 0.91 0.0160 74.53 0.0612 2.58 38.49Q3 t1:7 296.05 0.0760 0.0762 −0.21 0.1044 −37.37 0.0789 −3.82 35.89 t1:8 303.05 0.1335 0.1332 0.24 0.1492 −11.73 0.1314 1.60 28.71 t1:9 308.65 0.1965 0.2023 −2.96 0.2239 −14.23 0.1968 −0.16 25.33 t1:10 323.35 0.5563 0.5410 2.75 0.5260 5.44 0.5572 −0.16 17.02 t1:11 328.45 0.7473 0.7349 1.67 0.7359 1.49 0.7458 0.20 15.62 t1:12 333.15 0.9364 0.9604 −2.56 0.9527 −1.74 0.9369 −0.05 15.04 t1:13 w = 0.1001 t1:14 293.65 0.2763 0.2758 0.19 0.2985 −8.04 0.2768 −0.18 8.75 t1:15 298.15 0.3506 0.3482 0.70 0.3710 −5.81 0.3478 0.81 8.63 t1:16 303.35 0.4455 0.4494 −0.88 0.4583 −2.87 0.4507 −1.16 8.73 t1:17 308.65 0.5793 0.5746 0.80 0.5900 −1.85 0.5781 0.20 8.59 t1:18 313.15 0.7083 0.7002 1.15 0.7144 −0.86 0.7043 0.57 8.61 t1:19 317.85 0.8569 0.8521 0.56 0.8552 0.19 0.8552 0.19 8.75 t1:20 322.65 1.023 1.031 −0.70 1.012 1.13 1.032 −0.79 8.98 t1:21 327.75 1.251 1.248 0.23 1.233 1.46 1.247 0.33 9.07 t1:22 332.95 1.502 1.501 0.06 1.474 1.86 1.501 0.03 9.30 t1:23 338.55 1.797 1.810 −0.74 1.784 2.07 1.822 −0.03 9.66 t1:24 w = 0.2043 t1:25 293.55 0.2984 0.2964 0.68 0.3174 −6.37 0.3001 −0.57 8.06 t1:26 298.55 0.3878 0.3862 0.40 0.4050 −4.44 0.3800 2.00 7.96 t1:27 303.45 0.4795 0.4941 −3.04 0.4873 −1.63 0.4878 −1.73 8.12 t1:28 307.75 0.6039 0.6070 −0.51 0.6142 −1.71 0.6044 −0.09 7.91 t1:29 312.65 0.7532 0.7589 −0.76 0.7590 −0.77 0.7610 −1.04 7.92 t1:30 317.85 0.9773 0.9501 2.78 0.9855 −0.84 0.9548 2.30 7.67 t1:31 322.75 1.162 1.161 0.05 1.159 0.27 1.165 −0.25 7.94 t1:32 328.05 1.409 1.427 −1.27 1.397 0.91 1.425 −1.17 8.15 t1:33 333.15 1.716 1.721 −0.29 1.698 1.06 1.714 0.15 8.20 t1:34 339.25 2.127 2.126 0.04 2.100 1.28 2.115 0.54 8.38 t1:35 342.95 2.389 2.401 −0.51 2.354 1.45 2.395 −0.26 8.57 t1:36 w = 0.3001 t1:37 294.15 0.6576 0.6522 0.82 0.6576 0.00 0.6590 −0.22 3.77 t1:38 298.55 0.8399 0.8385 0.16 0.8436 −0.44 0.8311 1.04 3.67 t1:39 303.85 1.076 1.113 −3.44 1.076 0.03 1.104 −2.64 3.70 t1:40 308.15 1.413 1.380 2.34 1.427 −0.97 1.377 2.54 3.44 t1:41 313.55 1.769 1.777 −0.43 1.776 −0.40 1.783 −0.77 3.51 t1:42 319.45 2.292 2.292 0.00 2.297 −0.22 2.304 −0.51 3.50 t1:43 325.65 2.959 2.930 0.98 2.960 −0.05 2.939 0.67 3.52 t1:44 329.35 3.353 3.357 −0.11 3.347 0.17 3.360 −0.22 3.61 t1:45 333.55 3.874 3.884 −0.25 3.862 0.32 3.878 −0.10 3.69 t1:46 338.15 4.4960 4.509 −0.29 4.475 0.46 4.494 0.04 3.80 t1:47 w = 0.3926 t1:48 296.05 0.9771 0.9703 0.70 0.9945 −1.78 0.9777 −0.06 2.79 t1:49 303.65 1.3920 1.422 −2.16 1.398 −0.42 1.394 −0.16 2.83 t1:50 308.35 1.804 1.782 1.20 1.813 −0.50 1.784 1.12 2.72 t1:51 313.65 2.264 2.279 −0.67 2.265 −0.04 2.306 −1.88 2.75 t1:52 318.55 2.890 2.838 1.81 2.892 −0.07 2.862 0.98 2.67 t1:53 323.15 3.472 3.463 0.27 3.467 0.14 3.461 0.32 2.70 t1:54 328.15 4.211 4.269 −1.38 4.199 0.29 4.234 −0.55 2.74 t1:55 332.95 5.160 5.185 −0.48 5.145 0.28 5.150 0.19 2.71 t1:56 337.35 6.201 6.162 0.63 6.185 0.26 6.202 −0.02 2.67 t1:57 t1:58 w = 0.4991 t1:59 293.65 1.548 1.541 0.47 1.559 −0.71 1.561 −0.81 1.56 t1:60 299.25 2.021 2.003 0.86 2.030 −0.48 1.979 2.08 1.58 t1:61 303.25 2.349 2.400 −2.17 2.350 −0.04 2.378 −1.24 1.65 t1:62 307.35 2.873 2.872 0.03 2.877 −0.14 2.867 0.23 1.63 t1:63 313.25 3.658 3.685 −0.73 3.658 0.02 3.704 −1.26 1.67 t1:64 317.85 4.530 4.442 1.93 4.533 −0.07 4.471 1.30 1.65 t1:65 324.55 5.717 5.770 −0.93 5.709 0.13 5.788 −1.25 1.74 t1:66 328.15 6.705 6.607 1.47 6.701 0.06 6.611 1.41 1.72 t1:67 334.35 8.186 8.277 −1.11 8.172 0.17 8.258 −0.88 1.80 t1:68 338.15 9.468 9.458 0.10 9.455 0.15 9.439 0.31 1.80 t1:69 w = 0.5963 t1:70 294.15 1.746 1.736 0.52 1.754 −0.47 1.779 −1.91 1.42 t1:71 297.95 2.153 2.149 0.16 2.164 −0.53 2.083 3.21 1.39 t1:72 303.65 2.827 2.890 −2.26 2.835 −0.31 2.848 −0.77 1.40 t1:73 308.55 3.656 3.651 0.15 3.670 −0.37 3.684 −0.76 1.36 (continued on next page) 3L. Wang / Journal of Molecular Liquids xxx (2013) xxx–xxx Please cite this article as: L. Wang, J. Mol. Liq. (2013), http://dx.doi.org/10.1016/j.molliq.2013.08.013 T142143144 145 146 147 148149 150 151 152 t1:74 Table 1 (continued) t1:75 T/K 103x1 103xApel 102RDApel 10Q2 t1:76 w= 0.5963 t1:77 313.55 4.583 4.545 0.81 4 t1:78 318.05 5.587 5.451 2.43 5 t1:79 323.55 6.645 6.679 −0.51 6 t1:80 328.75 7.844 7.949 −1.33 7 t1:81 333.35 9.008 9.144 −1.51 8 t1:82 338.45 10.68 10.53 1.40 10 t1:83 t1:84 w = 0.6999 t1:85 293.65 2.246 2.256 −0.45 2 t1:86 299.25 3.028 3.000 0.92 3 t1:87 303.25 3.579 3.629 −1.39 3 t1:88 307.65 4.471 4.417 1.20 4 t1:89 312.75 5.544 5.463 1.46 5 t1:90 319.45 6.987 7.052 −0.93 6 t1:91 325.65 8.612 8.733 −1.41 8 t1:92 328.55 9.716 9.584 1.35 9 t1:93 332.85 10.77 10.92 −1.39 10 t1:94 338.15 12.81 12.66 1.16 12 t1:95 t1:96 w = 0.7859 t1:97 293.95 2.532 2.551 −0.73 2 t1:98 298.15 3.108 3.084 0.78 3 t1:99 3 t1:100 4 t1:101 5 t1:102 6 t1:103 8 t1:104 9 t1:105 11 t1:106 12 t1:107 e th t1:108 solu t1:109 4 L. Wang / Journal of Molecular Liquids xxx (2013) xxx–xxx the same temperature, the solubility of solute increases with the increase of the mass fraction of ethanol in (water + ethanol) binary system, and the solubility value in pure water is the minimum. 303.85 3.975 3.936 0.99 308.35 4.739 4.721 0.37 312.95 5.509 5.635 −2.28 317.95 6.741 6.762 −0.32 323.35 8.210 8.145 0.79 328.55 9.647 9.644 0.03 333.05 11.22 11.08 1.26 338.15 12.73 12.86 −0.96 w is the mass fraction of ethanol in mixture of ethanol + water; xApel, xλh, and xPE denot respectively; RDApel, RDλh, RDPE represent the relative deviations between experimental polynomial equations. U N C O R R E C3.4. Comparison among models The relative deviations (RDs) between experimental solubility values and calculated solubility data are given in Table 1. RD ¼ x1;i−x calcd i x1;i : ð5Þ 290 300 310 320 330 340 350 0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.010 0.011 0.012 0.013 0.014 x 1 T/K Fig. 3. Solubility x1 of 6-chloro-3-aminopyridazine in pure water and binary mixtures of water + ethanol (w — the mass fraction of ethanol in mixture of ethanol + water). ■, w = 0; ●, w = 0.1001; ○, w = 0.2043; ★, w = 0.3001; ▲, w = 0.3926; □, w = 0.4991; ▽, w = 0.5963; ☆, w = 0.6999; ◆, w = 0.7859. calculated data based on the modified Apelblat equation. calculated data based on the λh equation. calculated data based on the polynomial empirical equation. Please cite this article as: L. Wang, J. Mol. Liq. (2013), http://dx.doi.org/10.10 E D P R O O F The root-mean-square deviations (RMSDS) between experimental solubility data and calculated values were calculated according to Eq. (6), and are listed in Table 2. 3xλh 102RDλh 103xPE 102RDPE γ1 .594 −0.26 4.624 −0.90 1.35 .598 −0.19 5.512 1.33 1.35 .641 0.06 6.654 −0.14 1.44 .828 0.21 7.837 0.09 1.51 .981 0.31 9.040 −0.35 1.58 .64 0.33 10.66 0.13 1.62 .240 0.26 2.251 −0.26 1.08 .034 −0.18 2.992 1.22 1.05 .582 −0.09 3.640 −1.72 1.08 .483 −0.26 4.450 0.48 1.06 .557 −0.23 5.499 0.82 1.08 .991 −0.05 7.050 −0.90 1.15 .608 0.05 8.682 −0.82 1.21 .715 0.01 9.524 1.98 1.21 .75 0.14 10.88 −1.09 1.29 .79 0.14 12.78 0.17 1.33 .529 0.15 2.551 −0.73 0.97 .112 −0.11 3.084 0.78 0.97 .982 −0.17 3.936 0.99 1.00 .745 −0.13 4.721 0.37 1.04 .508 0.02 5.635 −2.28 1.10 .744 −0.04 6.762 −0.32 1.12 .213 −0.04 8.145 0.79 1.15 .644 0.03 9.644 0.03 1.22 .21 0.03 11.08 1.26 1.25 .72 0.12 12.86 −0.96 1.34 e solubility data of solute calculated by Apelblat, λh and empirical polynomial equations, bility values and calculated results regressed respectively by Apelblat, λh and empirical RMSD ¼ 1 N XN i¼1 xcalcd1;i −x1;i x1;i !224 3 5 1 2 ð6Þ 153154where N denotes the number of solubility data points measured in one 155solvent; x1,icalcd and x1,i are the calculated solubility value and experimen- 156tal data, respectively. 157Tables 1 and 2 show that RDs of Apelblat and empirical polynomial 158equations are less than 3.82%, and RMSDS of the two equations are no 159more than 1.69%. So both the two models have satisfying fitting effects 160for all the experimental data. The λh equation can correlate well with 161the solubility data of solute in (ethanol + water) mixed solvents with 162the root-mean-square deviation being less than 3.33%, but it does not 163fit well for regressing the measured solubility data of 6-chloro-3- 164aminopyridazine in pure water. It is conjectured that the reason for 165poor fitting effects is that the pure water, as the strong polar inorganic 166solvent, can form a comparatively strong non-ideal solution with 6- 167chloro-3-aminopyridazine [13]. 1683.5. Prediction of dissolution properties 169At phase equilibrium, there is a universal solubility model according 170to basic thermodynamic theory [17,18]: lnx1γ1 ¼ ΔH tp R 1 T tp − 1 T ! − ΔCp R ln T tp T − T tp T þ 1 � � −ΔV R P−Ptp � � ð7Þ 171172where γ1 represents the activity coefficient of solute and ΔV is the vol- 173ume difference between phases of solid and liquid. Since the effects of 174the differences upon molar heat capacity under constant pressure ΔCp 175and pressure are very little, they can be ignored. The fusion temperature 16/j.molliq.2013.08.013 U N C O R R E C T O O F 176Tfus is close to triple point temperature Ttp, so Ttp and enthalpy of triple 177point ΔHtp often be replaced by Tm and enthalpy of fusion ΔHfus. Eq. (7) 178can be simplified as: lnx1 ¼ ΔHfus R 1 T fus − 1 T � � −lnγ1: ð8Þ 179180 181For the ideal solution, Eq. (8) can be written as: lnxid1 ¼ ΔH fus R 1 T fus − 1 T � � ð9Þ 182183where x1id denotes experimental mole fraction solubility of solute in 184ideal condition. 185The activity coefficient indicating the degree of deviation between 186real solution and ideal solution [19] is defined as: xid1 ¼ γ1 � x1: ð10Þ 187188 189The values of activity coefficients of 6-chloro-3-aminopyridazine are 190 191 192 193 194195 196Q5 197 198199 200 201 202 203 204 205 Ta bl e 2 t2 :1 t2 :2 Pa ra m et er s of m od ifi ed A pe lb la t, λh an d po ly no m ia le m pi ri ca le qu at io ns fo r 6- ch lo ro -3 -a m in op yr id az in e in pu re w at er an d bi na ry m ix tu re s of w at er + et ha no l, an d th e RM SD s of ex pe ri m en ta ls ol ub ili ty va lu es w it h th e ca lc ul at ed re su lt s. t2 :3 w M od ifi ed A pe lb la t λ h Po ly no m ia le m pi ri ca le qu at io n t2 :4 A B C 10 2 RM SD A p el λ h 10 2 RM SD λ h a b c d e 10 2 RM SD PE t2 :5 0 21 4. 94 − 16 11 4 − 29 .8 73 1. 69 29 .3 83 34 0. 11 32 .3 5 − 3. 35 45 0. 04 28 7 − 2. 05 · 10 − 4 4. 34 · 10 − 7 − 3. 44 · 10 − 1 0 1. 15 t2 :6 0. 10 01 13 6. 14 − 10 23 5 − 19 .2 66 0. 68 0. 18 66 6 25 69 9 3. 33 0. 63 33 7 − 0. 00 81 6 3. 96 · 10 − 5 − 8. 61 · 10 − 8 7. 09 · 10 − 1 1 0. 56 t2 :7 0. 20 43 12 8. 86 − 10 00 4 − 18 .1 10 1. 36 0. 26 94 5 18 71 1 2. 70 0. 96 63 0 − 0. 01 22 1 5. 81 · 10 − 5 − 1. 24 · 10 − 7 9. 95 · 10 − 1 1 1. 23 t2 :8 0. 30 01 23 9. 14 − 15 17 5 − 34 .2 86 1. 39 0. 33 82 5 13 42 6 0. 41 0. 55 20 5 − 0. 00 64 1 2. 81 · 10 − 5 − 5. 61 · 10 − 8 4. 38 · 10 − 1 1 1. 26 t2 :9 0. 39 26 29 .4 63 − 54 65 .8 − 3. 15 20 1. 20 0. 63 66 4 76 20 .3 0. 65 14 .4 88 − 0. 18 49 8 8. 90 · 10 − 4 − 1. 89 · 10 − 6 1. 51 · 10 − 9 0. 83 t2 :1 0 0. 49 91 32 .0 26 − 52 00 − 3. 65 90 1. 19 0. 52 68 2 80 79 .8 0. 29 5. 59 15 − 0. 07 14 6 3. 44 · 10 − 4 − 7. 37 · 10 − 7 5. 98 · 10 − 1 0 1. 19 t2 :1 1 0. 59 63 31 2. 18 − 18 27 2 − 45 .1 11 1. 35 0. 82 32 2 54 71 .7 0. 33 26 .5 94 − 0. 33 67 6 1. 60 · 10 − 3 − 3. 37 · 10 − 6 2. 67 · 10 − 9 1. 34 t2 :1 2 0. 69 99 23 7. 31 − 14 58 4 − 34 .0 95 1. 21 0. 55 75 7 71 35 .0 0. 17 8. 34 23 − 0. 10 60 8 5. 06 · 10 − 4 − 1. 08 · 10 − 6 8. 62 · 10 − 1 0 1. 10 t2 :1 3 0. 78 59 12 1. 37 − 89 98 .4 − 17 .0 19 1. 03 0. 41 67 4 88 73 .9 0. 10 − 23 .4 88 0. 29 95 4 1. 43 · 10 − 3 3. 03 · 10 − 6 − 2. 40 · 10 − 9 0. 71 t2 :1 4 A, B an d C ar e pa ra m et er s of m od ifi ed A pe lb la tm od el ;λ an d h ar e pa ra m et er s of λh m od el ;a ,b ,c ,d an d e ar e pa ra m et er s of po ly no m ia le m pi ri ca le qu at io n m od el ;R M SD A p el ,R M SD λ h an d RM SD PE de no te th e ro ot -m ea n- sq ua re de vi at io ns be tw ee n t2 :1 5 ex pe ri m en ta ls ol ub ili ty va lu es an d ca lc ul at ed re su lt s re gr es se d re sp ec ti ve ly by A pe lb la t, λh an d em pi ri ca lp ol yn om ia le qu at io ns . 5L. Wang / Journal of Molecular Liquids xxx (2013) xxx–xxx Please cite this article as: L. Wang, J. Mol. Liq. (2013), http://dx.doi.org/10.10 E D P Rshown in Table 1. It can be seen that, at the same temperature, the activ-ity coefficient of 6-chloro-3-aminopyridazine decreases with the in- crease of themass fraction of ethanol in themixture of ethanol + water. Eq. (9) can also be written as: lnxid1 ¼− ΔHfus RT þ ΔS fus R ð11Þ For the real solution, taking into account the solvent effect, Eq. (13) can be expressed as [21,22]: lnx1 ¼− ΔHdis RT þ ΔSdis R þ c ð12Þ where ΔHdis and ΔSdis denote enthalpy and entropy of dissolution, respectively; c is a constant. The logarithms of the saturated mole fraction solubility of 6-chloro- 3-aminopyridazine lnx1 and inverse of temperatures are presented in Fig. 4. The enthalpies of dissolution in Eq. (12) were obtained by regressing analysis on the experimental data, and are listed in Table 3. The positive values ofΔHdis in purewater and (water + ethanol) binary 0.0029 0.0030 0.0031 0.0032 0.0033 0.0034 -10 -9 -8 -7 -6 -5 -4 ln x 1 K/T Fig. 4. Relations between the logarithm of solubility lnx1 of 6-chloro-3-aminopyridazine and absolute temperature T. ■, w = 0; ●, w = 0.1001; ○, w = 0.2043;★, w = 0.3001; ▲, w = 0.3926;□, w = 0.4991;▽, w = 0.5963;☆, w = 0.6999; ◆, w = 0.7859. 16/j.molliq.2013.08.013 TE D P R O O F 206 mixtures reveal that 6-chloro-3-aminopyridazine being dissolved in all 207 the solvents we tested is an entropy-driving process. 208 4. Conclusions 209 The experimental solubility data of 6-chloro-3-aminopyridazine 210 in water and binary system of water + ethanol at temperatures 211 ranging from 293.55 K to 342.95 K at atmospheric pressureQ6 . The 212 fusion point temperature and enthalpy of fusion were determined 213 by DSC. The activity coefficients and the molar enthalpy of dissolu- 214 tion of 6-chloro-3-aminopyridazine were obtained. The solubility 215 of 6-chloro-3-aminopyridazine rises with the increase of tempera- 216 ture and the increase of the mass fraction of ethanol in the 217 (water + ethanol) mixture. The modified Apelblat and polynomial 218 empirical equations fit all the experimental solubility data of 6- 219 chloro-3-aminopyridazine well. But the measured solubility data 220 of 6-chloro-3-aminopyridazine in pure water could not be regressed 221 well by λh equation. 222 5.Q7 Uncited reference 223 [20] 224References 225[1] B. Stanovnik, M. Tišler, Tetrahedron 23 (1967) 387–395. 226[2] I. Ishaaya, D. Degheele, Insecticides with Novel Modes of Action: Mechanism and 227Application, 1st ed., Springer-Verlag, Berlin, Germany, 1998. 228[3] H. Oberlander, D.L. Silhacek, Pestic. Sci. 54 (1998) 300–302. 229[4] R.F. Sun, Y.L. Zhang, F.C. Bi, Q.M. Wang, J. Agric. Food Chem. 57 (2009) 6356–6361. 230[5] X.X. Cao, J.Q. Liu, T.T. Lv, J.C. Yao, J. Chem. Eng. Data 57 (2012) 1509–1514. 231[6] X.H. Shi, M. Li, C.R. 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Sun, Study on Engineering Foundation of Comprehensive Utilization of Mixed 246Dibisic Acids, Zhengzhou University, Zhengzhou, China, 2007. 247[17] Y. Zhang, L.S. Wang, R.H. Zhou, X.M. Liu, J. Chem. Eng. Data 56 (2011) 2090–2094. 248[18] M. W. Stanley, Phase Equilibria in Chemical Engineering, Butterworth, New York, 2491985. 250[19] E.M. Gonçalves, M.E. Minas da Piedade, J. Chem. Thermodyn. 47 (2012) 362–371. 251[20] J.R. Bourne, R.J. Davey, J. McCulloch, Chem. Eng. Sci. 33 (1978) 199–204. 252[21] H. Yan, Z. Wang, J.K. Wang, Ind. Eng. Chem. Res. 51 (2012) 2808–2813. 253[22] M. Mirmehrabi, S. Rohani, K.S.K. Murthy, B. Radatus, Int. J. Pharm. 282 (2004) 73–85. 254 255 Table 3t3:1 t3:2 Dissolution enthalpy ΔHdis of 6-chloro-3-aminopyridazine in pure water and binary mixtures of water + ethanol. t3:3 w = 0 w = 0.1001 w = 0.2043 w = 0.3001 w = 0.3926 w = 0.4991 w = 0.5963 w = 0.6999 w = 0.7859 t3:4 ΔHdis//kJ mol−1 56.370 34.540 35.396 36.322 37.157 33.650 33.738 31.966 30.247 6 L. Wang / Journal of Molecular Liquids xxx (2013) xxx–xxx U N C O R R E C Please cite this article as: L. Wang, J. Mol. Liq. (2013), http://dx.doi.org/10.10 16/j.molliq.2013.08.013 Measurement and correlation of the solubility of 6-„chloro-„3-„aminopyridazine in water and binary mixtures of water+ethano... 1. Introduction 2. Experimental 2.1. Materials 2.2. Fusion property measurements 2.3. Solubility measurements 3. Results and discussion 3.1. Property evaluation of pure components 3.2. Thermodynamic models 3.2.1. Modified Apelblat equation 3.2.2. λh (Buchowski) equation 3.2.3. Polynomial empirical equation 3.3. Solubility data of 6-chloro-3-aminopyridazine 3.4. Comparison among models 3.5. Prediction of dissolution properties 4. Conclusions 5. Uncited reference References