title: Observation of zinc phthalocyanine aggregates on a water surface using grazing incidence X-ray scattering.
abstract: Reported here are the structural properties of a zinc 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine Langmuir monolayer on a water surface under progressive lateral compression investigated by grazing incidence X-ray scattering. Grazing incidence diffuse X-ray scattering out of the specular plane (GIXOS) is exploited to determine specular reflectivity-like information where the phase change of flat-lying molecules on the surface to edge-standing molecules perpendicular to the surface is directly observed. Furthermore, grazing incident X-ray diffraction (GIXD) is used to investigate the in-plane ordering of the system where it has been found that in the high-density state (approximately 0.35 nm2 per molecule) the system can be considered to be a monolayer consisting of arrays of side-by-side lying cofacially aggregated cylindrical rodlike entities.
authors.affiliation: European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble, France. sean.oflaherty@physics.org
authors.forename: Seán M
authors.initials: SM
authors.lastname: O'Flaherty
authors.forename: Lutz
authors.initials: L
authors.lastname: Wiegart
authors.forename: Oleg
authors.initials: O
authors.lastname: Konovalov
authors.forename: Bernd
authors.initials: B
authors.lastname: Struth