Supporting Information

Solubility and Solid Phase Studies of Isomeric Phenolic Acids in Pure Solvents

Sérgio M. Vilas-Boasa,b,c, Paula Brandãod, Mónia A.R. Martinsa,b,d, Liliana P.

Silvad, Tatiana La Banca Schreinera,b, Luciano Fernandesc, Olga Ferreiraa,b,*,

Simão P. Pinhoa,b

aCentro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal

bLaboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal

cUTFPR- Departamento de Engenharia Química, Universidade Tecnológica Federal do Paraná, 84016-210 Ponta Grossa, Brazil

dCICECO − Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal

*Corresponding author: Olga Ferreira

Telephone: +351 273 303 087

Fax: +351 273 313 051

E-mail: oferreira@ipb.pt

Table S1: Crystal data and refinement parameters of hydrated protocatechuic acid.

Parameter Protocatechuic AcidEmpirical Formula C14H16O10

Mw 344.27Crystal System Triclinic

Space group P 1a / [Å] 7.927(3)b / [Å] 8.058(3)c / [Å] 12.500(4)α / [º] 77.323(13) / [º] 72.847(13)γ / [º] 72.382(13)V [Å3] 719.7(4)

Z 2Dc [Mg m-3] 1.589 / [mm-1] 0.138

Reflections collected 25521Unique reflections, [Rint] 4453 [0.0459]

Final R indices

R1, wR2 [I>2I] 0.0457, 0.1144[3212]

R1, wR2 (all data) 0.0715, 0.1315

Table S2: Overview of the literature solubility data for the studied phenolic acids.

Solute Solvent Temperature range (K) Reference

gallic acid

water 273.15 – 363.15 Lu and Lu [1]

water 293.15 – 318.15 Noubigh et al. [2]

water 288 – 323 Mota et al. [3]

water, methanol, ethanol, and ethyl acetate 298.2 – 333.2 Daneshfar et al.

[4]

water and methanol 293.15 – 318.15 Noubigh et al. [5]

water, 1-propanol, 2- propanol and acetonitrile 293.15 – 318.15 Dali et al. [6]

water 298 - 343 Dabir ei al. [7]

protocatechuic acid

water 293.15 – 318.15 Noubigh et al. [2]

water 288 – 323 Queimada et al. [8]

water 298.75 – 415.85 Srinivas et al. [9]

methanol, ethanol, methyl acetate and ethyl acetate 293.15 – 318.15 Noubigh et al.

[10]

Temp Cel260.0250.0240.0230.0220.0210.0200.0

DSC

mW

0.000

-1.000

-2.000

-3.000

-4.000

-5.000

-6.000

DDSC

mW

/min

250.3Cel-5.243mW

284.8mJ/mg

249.1Cel-2.912mW

249.8Cel-4.287mW

251.9Cel-1.555mW

Temp Cel215.0210.0205.0200.0195.0190.0

DSC

mW

2.00

0.00

-2.00

-4.00

-6.00

-8.00

-10.00

-12.00

-14.00

DDSC

mW

/min

b)

a)

Temp Cel220.0215.0210.0205.0200.0195.0190.0185.0180.0

DSC

mW0.00

-2.00

-4.00

-6.00

-8.00

-10.00

-12.00

-14.00

-16.00

-18.00

DDSC

mW

/min

c)

Temp Cel245.0240.0235.0230.0225.0

DSC

mW

1.000

0.000

-1.000

-2.000

-3.000

-4.000

-5.000

-6.000

-7.000

-8.000

-9.000

DDSC

mW

/min

d)

Figure S1: Exemplificative DSC thermograms for: a) Gallic acid; b) Protocatechuic acid; c) Gentisic

Acid and d) α-Resorcylic acid.

Table S3: Characterization of the solid samples obtained from evaporating the solvent from the saturated

solutions.

Compound CCDC/ RefcodeSpace

Group/crystal Pattern

Z Solvate Reference

Gallic Acid

820132 Monoclinic, C2/c 8 Anhydrate [11]

811292 Monoclinic, C2/c 8 Anhydrate [12]

837396 Monoclinic, C2/c 8 Anhydrate [13]

927226 Monoclinic, C2/c 4 Anhydrate [14]

Protocatechuic Acid

764265 Monoclinic P21/c 4 Monohydrate[15]

764266 Triclinic P1 6 Anhydrate

Gentisic Acid747937-747942

and 747946-747948

Monoclinic P21/c 4 Anhydrate [16]

α-Resorcylic Acid

762467 Monoclinic Cc 4 Acetylacetone solvate monohydrate

[15]

764268 Monoclinic P21/c 4 1,4-dioxane solvate

764269 Monoclinic Cc 4 tetrahydrofuran solvate monohydrate

764270 Monoclinic, C2/c 4 Anhydrate

764271 Monoclinic, C2/c 24 Anhydrate

Figure S2: Experimental X–ray powder diffraction pattern of protocatechuic acid from supplier and the

powder pattern calculated from the single-crystal X-ray diffraction data.

Figure S3: Experimental X–ray powder diffraction pattern of gallic acid from supplier and the powder

pattern calculated from the single-crystal X-ray diffraction data (CCDC 927226)

Figure S4: Experimental X–ray powder diffraction pattern of resorcylic acid from supplier and the

powder pattern calculated from the single-crystal X-ray diffraction data of resorcylic acid with CCDC

number 764271.

Table S4: Sample ID of the crystals obtained from gravimetry.

Solute Solvent ID

Gallic acid

Water W3Methanol B3

2-Butanone I3Ethyl Acetate F3

DMF 2IR

Protocatechuic Acid

Water 5wrMethanol B5Methanol 4BR

2-Butanone I62-Butanone 5IR

Ethyl Acetate F6DMF l5

α-Resorcylic Acid

Water W12Methanol B12

2-Butanone I12Ethyl Acetate F12

DMF R13

a

b

Figure S5: (a) Molecular structure of I5 sample; (b) Hydrogen bonds between protocatechuic acid

molecules.

Figure S6: Experimental X–ray powder diffraction pattern of W3, B3, I3, F3 and 2lR samples and the

powder pattern of gallic acid from supplier.

Figure S7: Experimental X–ray powder diffraction pattern of I6, 5IR, 4BR samples and the powder

pattern calculated from the single-crystal X-ray diffraction data of protocatechuic acid with CCDC

number 764266 [15].

Figure S8: Experimental X–ray powder diffraction pattern of F6, B5, I5, 5wr samples, the powder

pattern calculated using the single-crystal X-ray diffraction data of protocatechuic acid from supplier and

the protocatechuic acid with CCDC 764265 for comparison (hydrate form identified by Sarma et al. [15].

Figure S9: Experimental X–ray powder diffraction pattern of W12, B12, I12, F12 and R13 samples and

the powder pattern of resorcylic acid from supplier.

295 300 305 310 3150.01

0.1

1 a1-Propanol Exp1-Propanol CalcDMF ExpDMF Calc

Temperature (K)

Mol

e Fr

actio

n So

lubi

lity

295 300 305 310 3150.01

0.1

1 b1-Propanol Exp1-Propanol CalcDMF ExpDMF Calc

Temperature (K)

Mol

e Fr

actio

n So

lubi

lity

295 300 305 310 3150.01

0.1

1 c1-Propanol Exp1-Propanol CalcDMF ExpDMF Calc

Temperature (K)

Mol

e Fr

actio

n So

lubi

lity

296 298 300 302 304 306 308 310 312 314 3160.01

0.1

1 d1-Propanol Exp1-Propanol CalcDMF ExpDMF Calc

Temperature (K)

Mol

e Fr

actio

n So

lubi

lity

Figure S10: Predicted solubility data obtained through NRTL-SAC for: (a) gallic acid, (b) protocatechuic

acid, (c) gentisic acid and (d) α-resorcylic acid.

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