Solubilities of 5,10,15,20-Tetraphenylporphyrin ... - ACS Publications

Article pubs.acs.org/jced

Solubilities of 5,10,15,20-Tetraphenylporphyrin and 5,10,15,20Tetraphenylporphyrin Manganese(III) Chloride in Binary Ethanol + Water Solvent Mixtures Chunlin Li,† Qinbo Wang,*,† Binwei Shen,‡ Zhenhua Xiong,‡ and Chuxiong Chen‡ †

Department of Chemical Engineering, Hunan University, Changsha, 410082, P. R. China Zhejiang Shuyang Chemical Co. Ltd., Quzhou, 312402, P. R. China

‡

S Supporting Information *

ABSTRACT: The solubilities of 5,10,15,20-tetraphenylporphyrin (TPP) and 5,10,15,20-tetraphenylporphyrin manganese(III) chloride (TPPMnCl) in binary ethanol + water solvent mixtures at (303.2 to 333.2) K were determined at atmospheric pressure. The solubility of TPPMnCl in ethanol + water solvent mixtures is much larger than that of TPP. The effects of temperature and mass fraction of ethanol in the solvent mixtures on the solubilities were studied. It was found that the solvent composition has a significant influence on solubility. The solubility of TPP increases apparently with the increasing temperature for a certain solvent composition; however, the solubility of TPPMnCl only slightly increases with the increase of temperature at constant composition. The experimental data were correlated with the Nývlt equation, and good agreement between the experimentally determined and the correlated solubilities was obtained. Furthermore, the thermodynamic parameters including dissolution enthalpy, dissolution entropy, isobaric heat capacity, and Gibbs free energy of TPP and TPPMnCl in ethanol + water mixtures were calculated by the Clark−Glew equation.

1. INTRODUCTION 5,10,15,20-Tetraphenylporphyrin (TPP; molecular mass, 614.74; CAS registry no., 917-23-7; chemical structure drawn in Figure 1) and 5,10,15,20-tetraphenylporphyrin manganese-

Figure 2. Chemical structure of 5,10,15,20-tetraphenylporphyrin manganese(III) chloride.

dioxygen under mild conditions, similar to cytochrome P-450 monooxygenase in biological phenomena. Based on that, the metalloporphyrin presents high catalytic activities and high selectivities in the catalytic oxidation of hydrocarbons without coreducing reagents;14,15 consequently, the compound has received increasing attention from all areas of science. Although much research has been done on TPP and TPPMnCl, the majority of work focused on the method of chemical synthesis and applications of the compounds. Only a

Figure 1. Chemical structure of 5,10,15,20-tetraphenylporphyrin.

(III) chloride (TPPMnCl; molecular mass, 703.11; CAS registry no., 32195-55-4; chemical structure shown in Figure 2), have been widely studied for several decades because of their high importance in many fields involving molecular electronics and sensors,1,2 energy transfer,3 functional organic materials,4,5 field-effect transistors,6 medicine,7,8 and other applications in analytical chemistry.9 In addition, TPPMnCl has attracted great attention as an oxidation catalyst.10−13 This kind of metalloporphyrin has a catalytic effect on the activity of © XXXX American Chemical Society

Received: November 1, 2014 Accepted: January 7, 2015

A

DOI: 10.1021/je501002a J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

Article

GC. All the chemicals were used without further purifications. The detailed information on the used chemicals in the experiment is given in Table 1.

few researchers have attempted to investigate their purification methods to obtain products with high purity and high yield. Commercially, TPP might be obtained from the reaction of benzaldehyde with pyrrole under atmospheric pressure,16 and TPPMnCl might be obtained from the reaction of manganese(II) chloride tetrahydrate with TPP under atmospheric pressure.17 When the reaction is completed, the reaction mixtures are cooled down to room temperature, and TPP or TPPMnCl would crystallized out from the reaction mixtures. Then usually filtration is used to separate the crystallized product TPP or TPPMnCl from the solution. By this way, the crude product TPP or TPPMnCl is obtained. For crude TPP, a small amount of solvent propionic acid, unreacted benzaldehyde and pyrrole, byproducts such as dipyrrylmethenes, open-chain polypyrrylmethanes, and porphyrinogen are usually included. For crude TPPMnCl, small amounts of solvent N,N-dimethylformamide (DMF) and reactant metal-salt are included. To acquire high purity, the crude TPP and TPPMnCl could be thoroughly washed with ethanol + water mixtures, because the above-mentioned impurities usually have large solubilities in ethanol + water mixtures. Furthermore, ethanol is an extremely suitable solvent in crystallization and purification, because it is relatively cheaper and has a lower toxicity and a lower boiling-point, which makes the recovery of the washing solvent easier and economical. According to the above analysis, the solubility characteristics of TPP and TPPMnCl in binary ethanol + water solvent mixtures have a considerable influence on the designation of the corresponding separation and purification equipment, as well as the operation of the crystallization process. The thermodynamic properties of dissolution are also needed. However, besides the very recent studies about the solubility of 5,10,15,20-tetrakis(4-chlorophenyl) porphyrin manganese(III) chloride in N,N-dimethylformamide + water solvent mixtures18 and the solubility of 5,10,15,20-tetrakis(p-chlorophenyl)porphyrin in binary propionic acid + water solvent mixtures at (293.2 to 353.2) K having been published,19 the solubility of TPP and TPPMnCl have scarcely been reported up to date. In this study, the solubilities of TPP and TPPMnCl in ethanol + water solvent mixtures at the temperatures ranging from (303.2 to 333.2) K were determined at atmospheric pressure by the static method.20 The Nývlt equation was used to correlate the experimental data. To understand the solubility behavior of TPP and TPPMnCl in ethanol + water solvent mixtures, the thermodynamic parameters including dissolution enthalpy, dissolution entropy, isobaric heat capacity, and Gibbs free energy were investigated in detail with the Clark−Glew equation.

Table 1. Suppliers and Mass Fraction Purities of the Materials materials

suppliers

TPPa TPPMnClb ethanol CH2Cl2e

synthesized by ourself synthesized by ourself Aladdin Chemistry Co. Aladdin Chemistry Co.

mass fraction > > > >

0.98 0.98 0.997 0.995

analysis method HPLCc HPLCc GCd GCd

a

5,10,15,20-Tetraphenylporphyrin. b5,10,15,20-Tetraphenylporphyrin manganese(III) chloride. cHigh-performance liquid chromatography. d Gas chromatograph. eDichloromethane.

2.2. Apparatus and Procedures. The experimental apparatus and procedures have been described in our previous publications in detail.18−21 Briefly, an excess amount of TPP or TPPMnCl was taken into 100 mL glass bottles, which were placed in a constant temperature bath. The bottles were filled with known mass fraction of aqueous ethanol and sealed by a rubber stopper to stop the solvent from evaporating. The bottles were heated to the desired temperature, and the temperature was kept within ± 0.1 K by thermoelectric controlling system. The mixtures were stirred with Tefloncoated magnetic stirrers to accelerate the dissolution of solute TPP or TPPMnCl. Preliminary experiments indicated that at least 3 h was required to reach solid−liquid equilibrium. After the magnetic stirrer was stopped, the mixtures were allowed to settle for several hours. To verify the attainment of solid−liquid equilibrium, the clear supernatant solutions were sampled once an hour, and the concentration of TPP or TPPMnCl was determined. Results show that 6 h was required after stirring was stopped to allow the solid phase to precipitate down, because repetitive measurements during 5 h to 6 h and 6 h to 7 h indicated the results were reproducible with ± 3 %. For assurance, after stirring was stopped at each temperature, the solutions were kept isothermal and undisturbed for at least 24 h to ensure that the solutions had reached solid−liquid equilibrium. For TPP, in each measurement, a preweighed plastic syringe was prepared, defined as m0. Subsequently, about (0.3 to 1.3) mL of the clear supernatant solution in each bottle was withdrawn with the plastic syringe, the total weight of the syringe was weighed again and recorded as m1, and then the solution in the syringe was transferred quickly into a 25 mL volumetric flask (uncertainty of ± 0.01 mL). The difference between m1 and m0 is the amount of sampled saturated solution. To collect the possibly crystallized solute in the syringe, the syringe was washed with ethanol at least five times. The solution in the volumetric flask was diluted with ethanol to 25 mL, afterward the solubility of TPP in binary ethanol + water solvent mixtures could be determined by the method introduced in section 2.3. For TPPMnCl, the sampling process is the same as for TPP, except that approximately (0.1 to 0.2) mL of the clear upper solution in each bottle was withdrawn, the solution was diluted to 25 mL with CH2Cl2, and afterward about 0.5 mL of solution was withdrawn with a suction pipet and diluted to 25 mL with CH2Cl2 once more. Some of the solubility experiments were measured three times to check the repeatability. The uncertainty of mass measurement was ± 0.0001 g, and the

2. EXPERIMENTAL SECTION 2.1. Materials. TPP and TPPMnCl was synthesized by the method described in detail elsewhere,16,17 with both the chromatographic purity of TPP and TPPMnCl greater than 98 % in mass fraction. Ethanol was obtained from Aladdin Chemistry Co., with a purity greater than 99.7 % in mass fraction. The water content in ethanol was verified to be less than 0.1 % by Karl Fischer method. CH2Cl2 was obtained from Aladdin Chemistry Co., with a purity greater than 99.5 % in mass fraction. The water was purified to the resistivity of 18.2 MΩ·cm by a laboratory ultrapure water machine (Master-Q, purchased from Shanghai Hitech Instrumens Co., Ltd.). In this work, the purity of TPP and TPPMnCl were checked by HPLC, and the purity of ethanol and CH2Cl2 were verified by B



Article

Table 2. Mole Fraction Solubilities (x1) and Thermodynamic Parameters of the Dissolution of TPP in Ethanol + Water Solvent Mixtures at Temperature T = (303.2 to 333.2) K and Pressure p = 0.1 MPaa T K

RD 6

10 x1

6

10 xc1

%

ΔsolG0

ΔsolH0

−1c

kJ·mol

303.2 313.2 323.2 333.2

1.757 2.313 3.057 4.012

1.723 2.251 2.974 3.967

−1.91 −2.69 −2.72 −1.14

33.4 33.8 34.1 34.4

303.2 313.2 323.2 333.2

1.057 1.337 1.732 2.289

1.089 1.387 1.790 2.336

2.99 3.67 3.31 2.05

34.7 35.2 35.6 36.0

303.2 313.2 323.2 333.2

0.755 0.924 1.176 1.519

0.758 0.941 1.187 1.516

0.36 1.88 0.93 −0.24

35.5 36.2 36.7 37.1

303.2 313.2 323.2 333.2

0.581 0.704 0.859 1.067

0.566 0.685 0.843 1.052

−2.63 −2.72 −1.93 −1.37

36.2 36.9 37.5 38.1

303.2 313.2 323.2 333.2

0.466 0.542 0.648 0.798

0.450 0.530 0.637 0.777

−3.57 −2.15 −1.79 −2.62

36.8 37.6 38.3 38.9

303.2 313.2 323.2 333.2

0.371 0.425 0.508 0.598

0.379 0.436 0.511 0.610

2.36 2.45 0.56 1.93

37.3 38.2 38.9 39.7

kJ·mol

−1d

w3 = 1.000b 19.9 22.3 24.6 27.0 w3 = 0.980b 17.9 20.3 22.7 25.1 w3 = 0.960b 15.9 18.3 20.7 23.1 w3 = 0.940b 13.8 16.3 18.7 21.1 w3 = 0.920b 11.8 14.2 16.7 19.1 w3 = 0.900b 9.7 12.2 14.6 17.1

ΔsolS0 −1

J·mol ·K

ΔsolC0p −1e

−1

−1f

J·mol ·K

ζH

ζTS

%

%

−44.4 −36.7 −29.3 −22.3

234.9

59.58 65.98 72.14 78.49

40.42 34.02 27.86 21.51

−55.2 −47.6 −40.1 −32.7

237.7

51.59 57.67 63.76 69.72

48.41 42.33 36.24 30.28

−64.8 −57.1 −49.5 −42.1

240.1

44.79 50.55 56.40 62.26

55.21 49.45 43.60 37.74

−73.7 −65.9 −58.3 −51.0

242.2

38.12 44.17 49.87 55.38

61.88 55.83 50.13 44.62

−82.4 −74.6 −67.0 −59.4

243.9

32.07 37.77 43.60 49.10

67.93 62.23 56.40 50.90

−91.1 −83.2 −75.3 −67.9

245.4

26.01 31.94 37.53 43.07

73.99 68.06 62.47 56.93

a Standard uncertainties u are u(T) = 0.1 K, ur(p) = 0.02, ur(x) = 0.03, ur(ΔsolG0,ΔsolH0,ΔsolS0,ΔsolC0p) = 0.03. bw3 is the mass fraction of ethanol in ethanol + water mixture solvents. cCalculated by eq 8. dCalculated by eq 9. eCalculated by eq 10. fCalculated by eq 11.

uncertainty of temperature was ± 0.1 K. The reliability of the experimental apparatus and method had been verified in our previous work.18−21 2.3. Analysis. The concentration of TPP in the solution was analyzed with an UV-4802 spectrophotometer (Shanghai Unico Instrument Co., Ltd. Shanghai, China) at room temperature at the maximum absorption wavelength 414.5 nm. The typical UV−vis spectrum of TPP in ethanol is shown in Figure S1 in the Supporting Information. The calibration curve, as shown in Figure S2 in the Supporting Information, was prepared using the standard solutions in the appropriate concentration range by linear regression, which was expressed as

y1 = 0.7901c1

where c2 is the concentration of TPPMnCl in a solution, y2 stands for the corresponding absorbance at 477 nm, and the linearity was 0.9999. To verify the reliability of the analysis method, 10 mixtures of TPP + ethanol and TPPMnCl + ethanol of known concentration were analyzed. To check the repeatability, the 10 solutions were measured at least five times, and the repeatability was evaluated with a mean relative deviation of less than 2 %. The estimated associated uncertainty of the measured solubility values based on error analysis and repeated observation was within ± 3 %.

3. RESULTS AND DISCUSSION 3.1. Experimental Results. The mass fraction of ethanol in binary ethanol + water solvent mixtures is defined as w3, which is given in the Supporting Information. The mole fraction solubility of TPP (x1) and the mole fraction solubility of TPPMnCl (x2) in a binary ethanol + water solvent mixture are defined and given in the Supporting Information. Table 2 presents the determined mole fraction solubility of TPP in binary ethanol + water solvent mixtures. It can be seen that the solubility of TPP in ethanol + water solvent mixtures increases with increasing temperature for a certain solvent composition, and increases with increasing mass fraction of ethanol for a certain temperature.

(1)

where c1 is the concentration of TPP in a solution, y1 stands for the corresponding absorbance at 414.5 nm, and the linearity was 0.9999. The typical UV−vis spectrum of TPPMnCl in CH2Cl2 is shown in Figure S3 in the Supporting Information. It can be seen that 477 nm is the maximum absorption wavelength of TPPMnCl in CH2Cl2. In this work, 477 nm was chosen as the measurement wavelength. The calibration curve shown in Figure S4 in the Supporting Information is expressed as

y2 = 0.1670c 2

(2) C



Article

Table 3. Mole Fraction Solubilities (x2) and Thermodynamic Parameters of the Dissolution of TPPMnCl in Ethanol + Water Solvent Mixtures at Temperature T = (303.2 to 333.2) K and Pressure p = 0.1 MPaa T K

RD 6

10 x1

6

10 xc1

%

ΔsolG0 kJ·mol

−1c

303.2 313.2 323.2 333.2

2.993 2.997 3.002 3.012

3.018 3.021 3.027 3.036

0.83 0.93 1.00 1.12

14.6 15.1 15.6 16.1

303.2 313.2 323.2 333.2

2.723 2.729 2.732 2.736

2.683 2.685 2.689 2.696

−1.47 −1.40 −1.44 −1.33

14.9 15.4 15.9 16.3

303.2 313.2 323.2 333.2

2.419 2.420 2.424 2.430

2.397 2.398 2.401 2.406

−0.93 −0.88 −0.80 −0.77

15.2 15.7 16.2 16.7

303.2 313.2 323.2 333.2

2.118 2.119 2.120 2.125

2.142 2.143 2.145 2.149

1.13 1.18 1.25 1.35

15.5 16.0 16.5 17.0

303.2 313.2 323.2 333.2

1.896 1.898 1.896 1.897

1.916 1.917 1.919 1.922

1.05 1.10 1.11 1.40

15.8 16.3 16.8 17.4

303.2 313.2 323.2 333.2

1.712 1.714 1.719 1.722

1.721 1.723 1.725 1.728

0.55 0.62 0.61 0.53

16.1 16.6 17.1 17.6

303.2 313.2 323.2 333.2

1.549 1.551 1.555 1.557

1.546 1.548 1.550 1.553

−0.20 −0.10 −0.10 −0.13

16.3 16.8 17.4 17.9

303.2 313.2 323.2 333.2

1.410 1.410 1.411 1.414

1.396 1.398 1.400 1.403

−0.94 −0.81 −0.68 −0.56

16.5 17.1 17.6 18.2

303.2 313.2 323.2 333.2

1.270 1.272 1.275 1.282

1.261 1.264 1.266 1.269

−0.72 −0.54 −0.46 −0.49

16.8 17.4 17.9 18.4

303.2 313.2 323.2 333.2

1.150 1.151 1.153 1.157

1.144 1.146 1.149 1.152

−0.50 −0.29 −0.16 −0.14

17.1 17.6 18.2 18.7

303.2 313.2 323.2 333.2

1.032 1.034 1.036 1.039

1.041 1.044 1.047 1.050

0.94 1.20 1.24 1.29

17.3 17.9 18.5 19.0

ΔsolH0 J·mol

−1d

w3 = 1.000b 35.1 123.8 212.5 301.3 w3 = 0.980b 14.5 93.0 171.6 250.1 w3 = 0.960b 5.9 75.4 144.9 214.4 w3 = 0.940b 7.3 68.8 130.3 191.8 w3 = 0.920b 17.2 71.6 126.0 180.3 w3 = 0.900b 34.3 82.3 130.2 178.2 w3 = 0.880b 57.3 99.6 141.9 184.2 w3 = 0.860b 85.3 122.5 159.7 196.9 w3 = 0.840b 117.5 150.1 182.8 215.4 w3 = 0.820b 153.1 181.7 210.3 238.9 w3 = 0.800b 191.5 216.5 241.5 266.4

ΔsolS0 −1

ΔsolC0p −1e

J·mol ·K

−1

J·mol ·K

−1f

ζH

ζTS

%

%

−48.2 −47.9 −47.6 −47.4

8.9

0.24 0.82 1.36 1.87

99.76 99.18 98.64 98.13

−49.1 −48.8 −48.5 −48.3

7.9

0.10 0.61 1.08 1.53

99.90 99.39 98.92 98.47

−50.1 −49.8 −49.6 −49.4

7.0

0.04 0.48 0.90 1.29

99.96 99.52 99.10 98.71

−51.2 −51.0 −50.8 −50.6

6.2

0.05 0.43 0.79 1.13

99.95 99.57 99.21 98.87

−52.1 −51.9 −51.7 −51.6

5.4

0.11 0.44 0.75 1.04

99.89 99.56 99.25 98.96

−52.8 −52.7 −52.5 −52.4

4.8

0.21 0.50 0.76 1.01

99.79 99.50 99.24 98.99

−53.6 −53.5 −53.3 −53.2

4.2

0.35 0.59 0.82 1.03

99.65 99.41 99.18 98.97

−54.3 −54.2 −54.1 −54.0

3.7

0.52 0.72 0.91 1.08

99.48 99.28 99.09 98.92

−55.1 −55.0 −54.8 −54.7

3.3

0.70 0.86 1.02 1.17

99.30 99.14 98.98 98.83

−55.8 −55.7 −55.6 −55.5

2.9

0.90 1.03 1.16 1.28

99.10 98.97 98.84 98.72

−56.5 −56.5 −56.4 −56.3

2.5

1.11 1.21 1.31 1.40

98.89 98.79 98.69 98.60

a Standard uncertainties u are u(T) = 0.1 K, ur(p) = 0.02, ur(x) = 0.03, ur(ΔsolG0,ΔsolH0,ΔsolS0,ΔsolC0p) = 0.03. bw3 is the mass fraction of ethanol in ethanol + water mixture solvents. cCalculated by eq 8. dCalculated by eq 9. eCalculated by eq 10. fCalculated by eq 11.

D



Article

experimental and calculated solubilities of TPP and TPPMnCl are plotted in Figure 3 and Figure 4, respectively. As shown in

Table 3 presents the determined mole fraction solubility of TPPMnCl in binary ethanol + water solvent mixtures. It was found that the solubility of TPPMnCl in ethanol + water solvent mixtures increases with increasing mass fraction of ethanol for a certain temperature. However, for a certain solvent composition, the temperature influences the solubility slightly. 3.2. Correlation of Experimental Data. The melting temperature and fusion enthalpy of TPP and TPPMnCl are often unknown or unavailable. For this case, the solubilities were correlated with the Nývlt equation as a function of temperature.22,23 B + C ln T (3) T where x is the mole fraction of solute, T is the absolute temperature, and A, B, and C are the empirical model parameters. To use eq 3 to correlate the solubilities of TPP and TPPMnCl at different solvent compositions, the following empirical correlations were adopted.24 ln x = A +

Figure 3. Mole fraction solubilities (x1) of TPP in ethanol + water solvent mixtures at temperature T = (303.2 to 333.2) K and pressure p = 0.1 MPa: ■, w3 = 1.000; ●, w3 = 0.980; ▲, w3 = 0.960; ▼, w3 = 0.940; ◀, w3 = 0.920; ▶, w3 = 0.900. Scatter, experimental points; solid line, correlated results by eqs 3 and 4

A = A 0 + A1x3 + A 2 x32 B = B0 + B1x3 + B2 x32 C = C0 + C1x3 + C2x32

(4)

where x3 is the mole fraction of ethanol in ethanol + water mixtures, and Ai, Bi, and Ci are model parameters of the Nývlt equation. The model parameters, which employ model eqs 3 and 4, were summarized in Table 4. The optimum algorithm applied Table 4. Parameters of Nývlt Equation for TPP and TPPMnCl in Ethanol + Water Solvent Mixturesa Ai i=0 i=1 i=2 i=0 i=1 i=2

−224.78 −13.907 43.402 −8.4467 5.5369 −10.046

Bi TPP 15147 −11142 2164.2 TPPMnCl −228.95 390.53 157.82

Ci

ARD/%

28.931 5.7841 −6.4584

2.08

−0.001527 −0.40333 1.4722

0.82

Figure 4. Mole fraction solubilities (x2) of TPPMnCl in ethanol + water solvent mixtures at temperature T = (303.2 to 333.2) K and pressure p = 0.1 MPa: ■, w3 = 1.000; ●, w3 = 0.980; ▲, w3 = 0.960; ▼, w3 = 0.940; ◀, w3 = 0.920; ▶, w2 = 0.900; ⧫, w3 = 0.880; ○, w3 = 0.860; ☆, w3 = 0.840; ◊, w3 = 0.820; □, w3 = 0.800. Scatter, experimental points; solid line, correlated results by eqs 3 and 4

a

Table 4, the ARD value of TPP and TPPMnCl is 2.08 % and 0.82 %, respectively. It shows that the calculated results show good agreement with the experimental data, and the Nývlt equation shows a high accuracy in correlating the solubility of TPP and TPPMnCl in ethanol + water solvent mixtures. The results shown in Figure 3 and Figure 4 verified the conclusion. 3.3. Thermodynamic Parameters of Solution. To better understand the dissolution process of TPP and TPPMnCl in ethanol + water solvent mixtures, the thermodynamic parameters of solution such as dissolution enthalpy ΔsolH0 (J· mol−1), dissolution entropy ΔsolS0 (J·mol−1·K−1), Gibbs free energy ΔsolG0 (kJ·mol−1), and isobaric heat capacity ΔsolC0p (J· mol−1·K−1) should be derived from the experimentally determined solubilities by using the Clark−Glew equation19,26,27 and assuming that the values of ΔsolCp0 are temperature-independent for the temperature range studied.19,28 The Clark−Glew equation is written as

Standard uncertainties u are u(T) = 0.1 K, ur(p) = 0.02, ur(Ai, Bi, Ci) = 0.03.

in the parameter estimation program was the Nelder−Mead Simplex approach,25 which had been described and used in detail in our previous work.18,19 Function f minsearch in the optimization toolbox of Matlab (Mathwork, MA) uses the Nelder−Mead Simplex approach. The objective function is the averaged relative deviation (ARD) between the experimental and calculated solubility, which is defined as ARD =

1 n

n

∑ abs(RDi), i=1

RDi =

xci − xi 100 xi

(5)

where n is the total number of experimental points, xci and xi are the ith calculated and experimental solubility, respectively. The correlated results and the corresponding RD values are given in Table 2 and Table 3. The averaged relative deviation (ARD) defined in eq 5 is given in Table 4. For comparison, the E


Journal of Chemical & Engineering Data Δsol Gθ0 Δ H0 ⎡ 1 1⎤ + sol θ ⎢ − ⎥ Rθ R ⎣θ T⎦ Δsol C p0θ ⎡ θ ⎛ T ⎞⎤ + ⎢⎣ − 1 + ln⎜⎝ ⎟⎠⎥⎦ θ R T

Article

On the other hand, the values of ΔsolG0 increase gradually with increasing temperature and decreasing mass fraction of ethanol. While the values of ΔsolS0 are negative in all cases, the negative ΔsolS0 values suggest the dissolving process is not entropydriven. From Table 3 and Figures S8 to S10 in the Supporting Information, the ΔsolH0, ΔsolG0, and ΔsolC0p of TPPMnCl are positive in all cases, indicating that the dissolution process of the studied system is endothermic and not spontaneous. The values of ΔsolH0 show a gradual increase with increasing temperature; however, the ΔsolH0 decline at higher concentrations of ethanol, then increase as the concentration of water increases, and a minimum of the dissolution enthalpy is obtained. The values of ΔsolG0 increase gradually with increasing temperature and increase with decreasing mass fraction of ethanol. This indicates that the water added into the solvent system causes a marked decrease on the solubility of TPPMnCl. However, the values of ΔsolS0 are negative in all cases, which suggest the dissolving process is not entropydriven.

ln x = −

(6)

where x is the mole fraction of solute, R is the gas constant, θ is the reference temperature, T is the experiment temperature, and ΔsolH0θ, ΔsolG0θ, and ΔsolC0pθ are the dissolution enthalpy, Gibbs free energy, and isobaric heat capacity at reference temperature, respectively. Since ΔsolH0 is a well-behaved function of T, the ΔsolH0 can be properly expressed as a perturbation on the value ΔsolH0θ at reference temperature θ using the Taylor’s series expansion26 Δsol H 0 = Δsol Hθ0 + Δsol C p0θ(T − θ )

(7)

Δsol G 0 = −RT ln x

(8)

By combining the Clark−Glew equation with the used Nývlt equation (eq 3), one can obtain Δsol H 0 = R(CT − B) °

Δsol S ° =

(9)

4. CONCLUSIONS The solubilities of TPP and TPPMnCl in ethanol + water solvent mixtures at the temperatures ranging from (303.2 to 333.2) K were determined at atmospheric pressure. The effects of temperature and mass fraction of ethanol in the solvent mixtures on the solubilities were studied. The following conclusions could be reached: (1) The solubility of TPP in ethanol + water solvent mixtures increases with an increase of temperature for a certain solvent composition, and decreases with the decreasing mass fraction of ethanol for a certain temperature. (2) The solubility of TPPMnCl in ethanol + water solvent mixtures decreases with the decreasing mass fraction of ethanol for a certain temperature, while the temperature only slightly influences the solubility. (3) The solubility of TPP in ethanol + water solvent mixtures is quite small, which indicates that ethanol is a suitable solvent to purify TPP. Although the solubility of TPPMnCl in the ethanol + water solvent mixtures is larger than that of TPP, ethanol also can be used to purify TPPMnCl. (4) The Nývlt equation was employed to correlate the experimental data; the solubilities calculated by the model were in satisfactory agreement with experimental data. (5) The thermodynamic parameters (ΔsolH0, ΔsolS0, ΔsolG0, ΔsolC0p) of solution were calculated by the Clark and Glew equation, the ΔsolH0, ΔsolG0, and ΔsolC0p are positive, while the ΔsolS0 is negative in all cases; the dissolving process is endothermic, not spontaneous and not entropy-driven. The experimental solubility and obtained thermodynamic parameters could be helpful in the purification and application of TPP and TPPMnCl.

°

Δsol H − Δsol G = R(A + C + C ln T ) T

Δsol C p0 = CR

(10) (11)

where A, B, and C are the parameters of Nývlt equation. The thermodynamic parameters of dissolution for TPP and TPPMnCl in ethanol + water solvent mixtures are listed in Table 2 and Table 3, respectively. Figures S5 to S10 in the Supporting Information show the obtained thermodynamic parameters as functions of solvent composition at experiment temperature. The relative contribution of enthalpy (ζH %) and entropy (ζTS %) to the Gibbs energy can be calculated from eqs 12 and 13.29−32 ζH% =

ζTS% =

|Δsol H 0| |Δsol H 0| + |T Δsol S 0|

100

|T Δsol S 0| |Δsol H 0| + |T Δsol S 0|

(12)

100 (13)

The values of ζH % and ζTS % are summarized in Table 2 and Table 3. In Table 2 the results show that the values of ζH % are in the range of (26.01 % to 78.49 %), and at higher concentrations of ethanol the main contributor to Gibbs free energy of the dissolving process of TPP is the enthalpy. In Table 3, the values of ζH % range from 0.04 % to 1.87 %, which indicated that in all circumstances the main contributor to the Gibbs free energy of the dissolving process of TPPMnCl is the entropy. From Table 2 and Figures S5 to S7 in the Supporting Information, the ΔsolH0, ΔsolG0, and ΔsolC0p of TPP are positive in all cases, which indicate that the dissolving process is endothermic and not spontaneous. It is additionally consistent with the fact that the solubilities of TPP in ethanol + water solvent mixtures increase with the increasing experimental temperature for a certain solvent composition. The values of ΔsolH0 exhibit an increasing trend with increasing temperature and a decreasing trend with decreasing mass fraction of ethanol.

■

ASSOCIATED CONTENT

S Supporting Information *

Additional calculations; UV−vis spectra; dissolution thermodynamic parameters. This material is available free of charge via the Internet at http://pubs.acs.org.

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. F



Article

Funding

(18) Li, C. L.; Wang, Q. B.; Shen, B. W.; Xiong, Z. H.; Chen, C. X. Solubilities of 5,10,15,20-tetrakis(4-chlorophenyl) porphyrin manganese(III) chloride in N,N-dimethylformamide + water mixtures. Fluid Phase Equilib. 2014, 380, 128−131. (19) Li, C. L.; Wang, Q. B.; Shen, B. W.; Xiong, Z. H.; Chen, C. X. Solubilities of 5,10,15,20-tetrakis(p-chlorophenyl)porphyrin in binary propionic acid + water solvent mixtures at (293.2 to 353.2) K. J. Chem. Eng. Data 2014, 59, 3953−3959. (20) Wang, Q. B.; Hou, L. X.; Cheng, Y. W.; Li, X. Solubilities of benzoic acid and phthalic acid in acetic acid + water solvent mixtures. J. Chem. Eng. Data 2007, 52, 936−940. (21) Shen, B. W.; Wang, Q. B.; Wang, Y. F.; Ye, X.; Lei, F. Q.; Gong, X. Solubilities of adipic acid in acetic acid + water mixtures and acetic acid + cyclohexane mixtures. J. Chem. Eng. Data 2013, 58, 938−942. (22) Nývlt, J. Solubilities of magnesium sulfite. J. Therm. Anal. Calorim. 2001, 66, 509−512. (23) Silva, A. P. M; Silva, J. F. C. Determination of the adipic acid solubility curve in acetone by using ATR-FTIR and heat flow calorimetry. Org. Process Res. Dev. 2011, 15, 893−897. (24) Li, L.; Feng, L.; Wang, Q. B.; Li, X. Solubility of 1,2,4benzenetricarboxylic acid in acetic acid + water solvent mixtures. J. Chem. Eng. Data 2008, 35, 298−300. (25) Nelder, J. A.; Mead, R. A simplex method for function minimization. Comput. J. 1965, 7, 308−313. (26) Clarke, E. C. W.; Glew, D. N. Evaluation of thermodynamic functions from equilibrium constants. Trans. Faraday Soc. 1966, 62, 539−547. (27) Kustov, A. V.; Berezin, M. B. Thermodynamics of solution of hemato- and deuteroporphyrins in N,N-dimethylformamide. J. Chem. Eng. Data 2013, 58, 2502−2505. (28) Takebayashi, Y.; Sue, K.; Yoda, S.; Hakuta, Y.; Furuya, T. Solubility of terephthalic acid in subcritical water. J. Chem. Eng. Data 2012, 57, 1810−1816. (29) Liu, M. J.; Fu, H. L.; Yin, D. P.; Zhang, Y. L.; Lu, C. C.; Cao, H.; Zhou, J. Y. Measurement and correlation of the solubility of enrofloxacin in different solvents from (303.15 to 321.05) K. J. Chem. Eng. Data 2014, 59, 2070−2074. (30) Yang, P. P.; Wen, Q. S.; Wu, J. L.; Zhuang, W.; Zhang, Y. H.; Ying, H. J. Determination of solubility of cAMPNa in water + (ethanol, methanol, and acetone) within 293.15−313.15 K. Ind. Eng. Chem. Res. 2014, 53, 10803−10809. (31) Sun, Z. H.; Hao, H. X.; Xie, C.; Xu, Z.; Yin, Q. X.; Bao, Y.; Hou, B. H.; Wang, Y. L. Thermodynamic properties of Form A and Form B of florfenicol. Ind. Eng. Chem. Res. 2014, 53, 13506−13512. (32) Tao, M. Y.; Wang, Z.; Gong, J. B.; Hao, H. X.; Wang, J. K. Determination of the solubility, dissolution enthalpy, and entropy of pioglitazone hydrochloride (form II) in different pure solvents. Ind. Eng. Chem. Res. 2013, 52, 3036−3041.

The project was granted financial support from Key S&T Special Project of Zhejiang Province (2012C13007-2) and the Fundamental Research Funds for the Central Universities. Notes

The authors declare no competing financial interest.

■

REFERENCES

(1) Liu, Z.; Yasseri, A. A.; Lindsey, J. S.; Bocian, D. F. Molecular memories that survive silicon device processing and real-world operation. Science. 2003, 302, 1543−1545. (2) Papkovsky, D. B.; O’Riordan, T.; Soini, A. Phosphorescent porphyrin probes in biosensors and sensitive bioassays. Biochem. Soc. Trans. 2000, 28, 74−77. (3) Maligaspe, E.; Kumpulainen, T.; Lemmetyinen, H.; Tkachenko, N. V.; Subbaiyan, N. K.; Zandler, M. E.; D’Souza, F. Ultrafast singletsinglet energy transfer in self-assembled via metal−ligand axial coordination of free-base porphyrin−zinc phthalocyanine and freebase porphyrin−zinc naphthalocyanine dyads. J. Phys. Chem. A 2010, 114, 268−277. (4) Li, Q.; Surthi, S.; Mathur, G.; Gowda, S.; Zhao, Q.; Sorenson, T. A.; Tenent, R. C.; Muthukumaran, K.; Lindsey, J. S.; Misra, V. Multiple-bit storage properties of porphyrin monolayers on SiO2. Appl. Phys. Lett. 2004, 85, 1829−1831. (5) Lu, J. T.; Wu, L. Z.; Jiang, J. Z.; Zhang, X. M. Helical nanostructures of an optically active metal-free porphyrin with four optically active binaphthyl moieties: Effect of metal-ligand coordination on the morphology. Eur. J. Inorg. Chem. 2010, 2010, 4000−4008. (6) Huang, X. B.; Zhu, C. L.; Zhang, S. M.; Li, W. W.; Guo, Y. L.; Zhan, X. W.; Liu, Y. Q.; Bo, Z. S. Porphyrin−dithienothiophene πconjugated copolymers: Synthesis and their applications in field-effect transistors and solar cells. Macromolecules 2008, 41, 6895−6902. (7) Sternberg, E. D.; Dolphin, D. Porphyrin-based photosensitizers for use in photodynamic therapy. Tetrahedron 1998, 54, 4151−4202. (8) Konan, Y. N.; Cerny, R.; Favet, J.; Berton, M.; Gurny, R.; Allemann, E. Preparation and characterization of sterile sub-200 nm meso-tetra(4-hydroxylphenyl)porphyrin-loaded nanoparticles for photodynamic therapy. Eur. J. Pharm. Biopharm. 2003, 55, 115−124. (9) Biesaga, M.; Pyrzyńska, K. Trojanowicz, Marek. Porphyrins in analytical chemistry. A review. Talanta 2000, 51, 209−224. (10) Dolphin, D.; Traylor, T. G.; Xie, L. Y. Polyhaloporphyrins: Unusual ligands for metals and metal-catalyzed oxidations. Acc. Chem. Res. 1997, 30, 251−259. (11) Jiang, Q.; Hu, H. Y.; Guo, C. C.; Liu, Q.; Song, J. X.; Li, Q. H. Aerobic liquid-phase oxidation of p-xylene over metalloporphyrins. J. Porphyrins Phthalocyanines 2007, 11, 524−530. (12) Hu, B. Y.; Yuan, Y. J.; Xiao, J.; Guo, C. C.; Liu, Q.; Tan, Z.; Li, Q. H. Rational oxidation of cyclohexane to cyclohexanol, cyclohexanone, and adipic acid with air over metal. J. Porphyrins Phthalocyanines 2008, 12, 27−34. (13) Xiao, Y.; Luo, W. P.; Zhang, X. Y.; Guo, C. C.; Liu, Q.; Jiang, G. F.; Li, Q. H. Aerobic oxidation of p-toluic acid to terephthalic acid over T(p-Cl)PPMnCl/Co(OAc)2 under moderate conditions. Catal. Lett. 2010, 134, 155−161. (14) Meunier, B. Metalloporphyrins as versatile catalysts for oxidation reactions and oxidative DNA cleavage. Chem. Rev. 1992, 92, 1411−1456. (15) Zhang, R.; Horner, J. H.; Newcomb, M. Laser flash photolysis generation and kinetic studies of porphyrin−manganese−oxo intermediates. Rate constants for oxidations effected by porphyrin− MnV−oxo species and apparent disproportionation equilibrium constants for porphyrin−MnIV−oxo Species. J. Am. Chem. Soc. 2005, 127, 6573−6582. (16) Adler, A. D.; Longo, F. R.; Finarelli, J. D.; Goldmacher, J.; Assour, J.; Korsakoff, L. A simplified synthesis for meso-tetraphenylporphyrin. J. Org. Chem. 1967, 32, 476−476. (17) Adler, A. D.; Longo, F. R.; Kim, J. On the preparation of metalloporphyrins. J. Inorg. Nucl. Chem. 1970, 32, 2443−2445. G


Solubilities of 5,10,15,20-Tetraphenylporphyrin ... - ACS Publications

Recommend Documents