JBPC  Vol.5 No.3 , August 2014
Acid Dissociation Constants and Related Thermodynamic Functions of Protonated 2,2-Bis(Hydroxymethyl)-2,2’,2”- Nitrilotriethanol (BIS-TRIS) from (278.15 to 328.15) K
ABSTRACT
Thermodynamic dissociation constants pKa of 2,2-bis(hydroxymethyl)-2,2’,2”-nitrilotriethanol have been determined at 12 temperatures from (278.15 to 328.15) K including the body temperature 310.15 K by the electromotive-force measurements (emf) of hydrogen-silver chloride cells without liquid junction of the type: Pt(s), H2(g), 101.325 kPa|BIS-TRIS (m) + BIS-TRIS·HCl (m)| AgCl(s), Ag(s), where m denotes molality. The pKa values for the dissociation process of BIS-TRIS·H++ H2O = H3O+ + BIS-TRIS given as a function of T in Kelvin (K) by the equation pKa = 921.66 (K/T) + 14.0007-1.86197 ln(T/K). At 298.15 and 310.15 K, the values of pKa for BIS-TRIS were found to be 6.4828 ± 0.0005 and 6.2906 ± 0.0006 respectively. Thus buffer solutions composed of BIS-TRIS and its hydrochloride would be useful as secondary pH buffer standards and for control of acidity in the pH range 6 to 8. At 298.15 K the thermodynamic functions G°, H°, S° and Cp° for the dissociation process of BIS-TRIS·H+ are G°=37,005 J·mol-1, H° = 28,273 J·mol-1, S°= 29.3 J·K-1·mol-1 and Cp° = 36 J·K-1·mol-1. These results are compared with the dissociation of protonated bases structurally related to BIS-TRIS·H+.

Cite this paper
Roy, R. , Roy, L. , Hundley, K. , Dinga, J. , Medcalf, M. , Tebbe, L. , Parmar, R. and Veliz, J. (2014) Acid Dissociation Constants and Related Thermodynamic Functions of Protonated 2,2-Bis(Hydroxymethyl)-2,2’,2”- Nitrilotriethanol (BIS-TRIS) from (278.15 to 328.15) K. Journal of Biophysical Chemistry, 5, 118-124. doi: 10.4236/jbpc.2014.53013.
References
[1]   Bates, R.G., Roy, R.N. and Robinson, R.A. (1973) Buffer Standards of Tris(Hydroxymethyl)Methylglycine (“Tricine”) for the Physiological Range pH 7.2 to 8.5. Analytical Chemistry, 45, 1663-1666.
http://dx.doi.org/10.1021/ac60331a022

[2]   Wu, Y.C., Berezansky, P.A., Feng, D. and Koch, W.F. (1993) Second Dissociation Constant of 3-(N-Morpholino)-2- Hydroxypropanesulfonic Acid and pH of Its Buffer Solutions. Analytical Chemistry, 65, 1084-1087.
http://dx.doi.org/10.1021/ac00056a023

[3]   Durst, R.A. and Staples, B.R. (1972) Itrs/Tris HCl: A Standard Buffer for Use in the Physiological pH Range. Clinical Chemistry, 18, 206-208.

[4]   Roy, R.N., Roy, L.N., Le Noue, S.R., Denton, C.E., Simon, A.N., Richards, S.J., et al. (2006) Thermodynamic Constants of N-[Tris(Hydroxymethyl)Methyl-3-Amino]Propanesulfonic Acid (TAPS) from the Temperatures 278.15 K to 328.15 K. Journal of Chemical Thermodynamics, 38, 413-417.
http://dx.doi.org/10.1016/j.jct.2005.06.009

[5]   Bates, R.G., Vega, C.A. and White, D.R. (1978) Standards for pH Measurements in Isotonic Saline Media of Ionic Strength I = 0.16. Analytical Chemistry, 50, 1295-1300.
http://dx.doi.org/10.1021/ac50031a026

[6]   Bates, N.E., Winget, G.D., Winter, W., et al. (1966) Hydrogen Ion Buffers for Biological Research. Biochemistry, 5, 467-477.
http://dx.doi.org/10.1021/bi00866a011

[7]   Roy, R.N., Robinson, R.A. and Bates, R.G. (1973) Thermodynamics of the Two Dissociation Steps of N-Tris(Hydroxymethyl)Methylglycine (“Tricine”) in Water from 5 to 50°. Journal of the American Chemical Society, 95, 8231-8235.
http://dx.doi.org/10.1021/ja00806a004

[8]   Roy, L.N., Roy, R.N., Denton, C.E., LeNoue, S.R., Roy, C.N., et al. (2006) Second Dissociation Constant of Bis- [(2-Hydroxyethyl)Amino]Acetic Acid (BICINE) and pH of Its Buffer Solutions from 5 to 55°C. Journal of Solution Chemistry, 35, 605-624.
http://dx.doi.org/10.1007/s10953-005-9009-6

[9]   Hetzer, H.B. and Bates, R.G. (1961) Dissociation Constant of the Protonated Acid Form of 2-Amino-2-(Hydroxyme- thyl)-1,3-Propanediol [Tris-Hydroxymethyl)-Aminomethane] and Related Thermodynamic Quantities from 0 to 50°. Journal of Physical Chemistry, 65, 667-671.
http://dx.doi.org/10.1021/j100822a017

[10]   Bates, R.G. and Hetzer, H.B. (1962) Dissociation Constant 2-Ammonium-2-Methyl-1,3-Propanediol in Water from 0 to 50 and Related Thermodynamic Quantities. Journal of Physical Chemistry, 66, 308-311.
http://dx.doi.org/10.1021/j100808a027

[11]   Paabo, M. and Bates, R.G. (1970) Dissociation Constant of Protonated 2,2-Bis(Hydroxymwthyl)-2,2’,2”-Nitrilotriethanol (Bis-Tris) and Related Thermodynamic Functions from 0 to 50°. Journal of Physical Chemistry, 74, 702-705.
http://dx.doi.org/10.1021/j100699a003

[12]   Bates, R.G. and Pinching, G.D. (1949) Acidic Dissociation Constant of Ammonium Ion at 0 to 50°C and the Base Strength of Ammonia. Journal of Research of the National Bureau of Standards, 42, 419-430.
http://dx.doi.org/10.6028/jres.042.037

[13]   Roy, R.N., Moore, C.P., Carlsten, J.A., Good, W.S., Harris, P., Rook, J.M., Roy, L.N. and Kuhler, K.M. (1997) Second Dissociation Constants of Two Substituted Aminoethansulfonic Acids (MES) and (TES) in Water from 5 to 55°C. Journal of Solution Chemistry, 26, 1209-1216.
http://dx.doi.org/10.1023/A:1022937324983

[14]   Bates, R.G. (1973) Determination of pH. Wiley, New York, Chapter 10.

[15]   Ives, J.G. and Moseley, P.G.N. (1975) Derivation of Thermodynamic Functions of Ionization from Acidic Dissociation Constants. Journal Chemical Society Faraday Transactions I, 72, 1132-1143.
http://dx.doi.org/10.1039/f19767201132

[16]   Please, N.W. (1954) Estimation of the Variances of the Data Used in the Calculation of Dissociation Constants. Biochemistry Journal, 56, 196-201.

[17]   Hetzer, H.B., Robinson, R.A. and Bates, R.G. (1962) Dissociation Constant of t-Butylammonium Ion and Related Thermodynamic Quantities from 5 to 35°C. Journal of Physical Chemistry, 66, 2696-2698.
http://dx.doi.org/10.1021/j100818a080

[18]   Timimi, B.A. and Everett, D.H. (1968) The Thermodynamics of the Acid Dissociation of Some Amino-Alcohols in Water. Journal Chemical Society B, 1380-1386.
http://dx.doi.org/10.1039/j29680001380

[19]   Datta, S.P., Grzybowski, A.K. and Weston, B.A. (1963) The Acid Dissociation Constant of the Protonated Form of Tri(Hydroxymethyl)Methylamine. Journal Chemical Society, 792-796.
http://dx.doi.org/10.1039/jr9630000792

[20]   Cox, M.C., Everett, D.H., Landsmen, D.A. and Munn, R.J. (1968) The Thermodynamics of the Acid Dissociation of Some Alkylammonium Ions in Water. Journal Chemical Society B, 1373-1379.
http://dx.doi.org/10.1039/j29680001373

[21]   Bates, R.G. and Allen, G.F. (1960) Acid Dissociation Constant and Related Thermodynamic Quantities for Triethanolammonium Ion in Water from 0 to 50°C. Journal of Research of the National Bureau of Standards, 64A, 343-346.
http://dx.doi.org/10.6028/jres.064A.033

[22]   Roy, L.N., Roy, R.N., Bodendorfer, B., Downs, Z., et al. (2011) Buffer Standards for the Physiological pH of the Zwitterionic Buffer 3-[N-Tris(Hydroxymethyl)Methylamino]-2-Hydroxypropanesulfonic Acid (TAPSO) from (278.15 to 328.15) K. Journal of Biophysical Chemistry, 2, 414-421.
http://dx.doi.org/10.4236/jbpc.2011.24048

[23]   Roy, L.N., Roy, R.N., Downs, Z.M., Bodendorfer, B.M., Veliz, J.A., Stegner, J.M., Henson, I.B. and Wollen, J.T. (2011) Buffer Standards for Physiological pH of the Buffer N-(2-Acetamido)-2-Aminoethanesulfonic Acid from (278.15 - 328.15) K. Open Journal of Physical Chemistry, 1, 118-123.
http://dx.doi.org/10.4236/ojpc.2011.13016

 
 
Top