title: Interfacial activity of metal β-diketonato complexes: in situ generation of amphiphiles by water coordination.
abstract: Symmetric transition metal complexes of 2,4-pentanedione (acetyl acetone) are interfacially active: Spinning drop tensiometry reveals lowering of the interfacial tension at the water-organic interface, most pronounced for [Cr(acac)(3)], [Fe(acac)(3)], [Zr(acac)(4)], and [Hf(acac)(4)]. The interfacial activity is explained by the in situ generation of amphiphilic species. Based on tensiometry and (1)H and diffusion-ordered NMR spectroscopy (DOSY NMR), hydrogen bonding of the organically dissolved complexes with water, in some cases in combination with inner-sphere hydrolytic coordination, is identified as the primary origin of this amphiphilicity. The complexes are a rare example of symmetric molecules that turn amphiphilic only upon interfacial interaction with water.
authors.affiliation: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Coenraad R
authors.initials: CR
authors.lastname: van den Brom
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vogel
authors.forename: Christoph P
authors.initials: CP
authors.lastname: Hauser
authors.forename: Sebastian
authors.initials: S
authors.lastname: Goerres
authors.forename: Manfred
authors.initials: M
authors.lastname: Wagner
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
authors.forename: Clemens K
authors.initials: CK
authors.lastname: Weiss