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Mechanism of the odor‐adsorption effect of zinc ricinoleate. A molecular dynamics computer simulation
Author(s) -
Kuhn H.,
Müller F.,
Peggau J.,
Zekorn R.
Publication year - 2000
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-000-0137-9
Subject(s) - chemistry , molecular dynamics , adsorption , aqueous solution , zinc , molecule , odor , ammonia , nucleophile , computational chemistry , inorganic chemistry , organic chemistry , catalysis
Zinc ricinoleate [Zn(Ri) 2 ] is widely used in surfactant and detergent mixtures for the adsorption of odor‐active compounds. The mechanism of this process is not known. In this initial study, we discuss the results of molecular dynamics computer simulations that were performed to get more information and detailed insights into the interaction mechanism between Zn(Ri) 2 and odor‐active substances. The calculations, based on simple molecular mechanics approximations, simulated the dynamic features of the molecular structures of Zn(Ri) 2 in vacuum, in the oil phase, and in aqueous solution. We determined actual molecular conformations and simulated an adduct of ammonia with Zn(Ri) 2 . On close inspection, in the vacuum and oil phase structures, the Zn 2+ ion is almost completely shielded by the oxygen ligands. Calculated structural transitions caused by the interaction of Zn(Ri) 2 with water‐solvent molecules resulted in a weakening of the electrostatic shield. Nucleophilic attack of odor‐active compounds to the relatively unprotected Zn 2+ atom is easy to achieve in aqueous solution. Simulation of the addition product of Zn(Ri) 2 with ammonia revealed an elementary structural change, resulting in an increase of the solubility and adsorption activity of Zn(Ri) 2 . Molecular dynamics simulations showed that the results coincide with experimental observations.