Profile structures of ultrathin periodic and nonperiodic multilayer films containing a disubstituted diacetylene by high-resolution x-ray diffraction

Abstract

High-resolution, meridional x-ray difraction data were recorded from ultrathin Langmuir-Slodgett multilayer Slms containing five bilayers of either arachidic acid (AA}, pentacosa-10, 12diynoic acid (a disubstituted diacetylene monomer, DAM), the blue polymeric form of DAM (DAPb), or the red polymeric form (DAPr). In addition, periodic and nonperiodic three-bilayer multilayers containing various sequences of AA and DAPb or DAPr bilayers were similarly investi-

NEXAFS study of a 17,19-hexatriacontadiyne monolayer on Au(111)

“…These spectral changes cannot be interpreted as a result that the polymerization further proceeds ordinarily. It is well known that PDs exhibit chromatic transition from the blue phase, which is usually obtained directly from the monomer, to the red phase by several stimulations including UV irradiation [1][2][3][4][5][6][7][8][9][10]. Though the product directly obtained from HTDY on Au(1 1 1) has a quite small conjugation length and cannot be the blue phase PDs, a transition to a red-phase-like state may occur by UV irradiation.…”

“…The photopolymerization of diacetylene derivatives has been studied in single crystals [1][2][3][4], self-assembled monolayers (SAMs) [5] and Langmuir-Blodgett (LB) films [6][7][8][9][10][11]. Upon polymerization, the regularity in molecular packing is not lost and the conjugated diacetylene moiety C"CAC"C of the monomer is converted into a repeat unit of the acetylenic type CAC"CAC by connecting the outer carbons in the adjacent molecules with new double bonds .…”

Overlayer-induced ordering of the disordered surface monolayer in Langmuir-Blodgett multilayer thin films

“…However, given the finite spatial resolution of the derived multilayer electron density profiles, the all-trans chains could also be significantly tilted relative to the layer plane depending on the exact geometry of the carboxyl-carboxyl interaction between the apposed monolayers. In fact, the measured carboxylmethyl endgroup distances appear to vary systematically from 28 A to 26 A depending on the monolayer's position in the multilayer profile suggesting a corresponding systematic variation in p [9]. We note that chain tilt relative to the layer plane can also be measured independently (on the same specimens under identical conditions) via X-ray scattering parallel to the layer planes requiring synchrotron radiation for such ultrathin multilayer films and that such chain tilt may depend upon the degree of ionization of the carboxyl group.…”

Vectorially oriented membrane protein monolayers: profile structures via x-ray interferometry/holography

“…An automated Al foil changer was used to attenuate the incident beam intensity to protect the total-count-rate limited detector. Multilayer specimens were oscillated over the full angular range 0.30 < e < 6.50 and over a more limited range 1.80 < co < 6.5°for better counting statistics data collection at higher values of q.. Additional details of the diffraction conditions have been described previously (Fischetti et al, 1988).…”