title: Acidity Constant (pKa) Calculation of Large Solvated Dye Molecules: Evaluation of Two Advanced Molecular Dynamics Methods.
abstract: pH-Sensitive dyes are increasingly applied on polymer substrates for the creation of novel sensor materials. Recently, these dye molecules were modified to form a covalent bond with the polymer host. This had a large influence on the pH-sensitive properties, in particular on the acidity constant (pKa). Obtaining molecular control over the factors that influence the pKavalue is mandatory for the future intelligent design of sensor materials. Herein, we show that advanced molecular dynamics (MD) methods have reached the level at which the pKavalues of large solvated dye molecules can be predicted with high accuracy. Two MD methods were used in this work: steered or restrained MD and the insertion/deletion scheme. Both were first calibrated on a set of phenol derivatives and afterwards applied to the dye molecule bromothymol blue. Excellent agreement with experimental values was obtained, which opens perspectives for using these methods for designing dye molecules.
authors: Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052, Zwijnaarde, Belgium.|Department of Textiles, Ghent University, Technologiepark 907, 9052, Zwijnaarde, Belgium.
authors: Thierry
authors: T
authors: De Meyer
authors: Amsterdam Center for Multiscale Modeling and Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH, Amsterdam, The Netherlands.
authors: Bernd
authors: B
authors: Ensing
authors: Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052, Zwijnaarde, Belgium.
authors: Sven M J
authors: http://orcid.org/0000-0003-4493-5708
authors: SM
authors: Rogge
authors: Department of Textiles, Ghent University, Technologiepark 907, 9052, Zwijnaarde, Belgium.
authors: Karen
authors: K
authors: De Clerck
authors: Amsterdam Center for Multiscale Modeling and Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH, Amsterdam, The Netherlands.
authors: Evert Jan
authors: EJ
authors: Meijer
authors: Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052, Zwijnaarde, Belgium.
authors: Veronique
authors: V
authors: Van Speybroeck
keywords: acidity; dyes/pigments; free energy methods; molecular dynamics; steered molecular dynamics