Molecular Orientation and Structural Transformations in Phthalic Anhydride Thin Films on MgO(100)/Ag(100)

Mohr S, Xu T, Döpper T, Laurin M, Görling A, Libuda J (2015)


Publication Language: English

Publication Status: Published

Publication Type: Journal article

Publication year: 2015

Journal

Publisher: American Chemical Society

Book Volume: 31

Pages Range: 7806-7814

Journal Issue: 28

DOI: 10.1021/acs.langmuir.5b01392

Abstract

Structural control of organic thin films on dielectric substrates is the key to tailoring the. physical properties of hybrid Materials, for example, for application in solar energy conversion, molecular electronics, or catalysis. In, this work, we investigate the molecular orientation of phthalic: anhydride (PAA) films on atomically well-defined mgO(100) on Ag(100) using temperature-programmed infrared reflection absorption spectroscopy (TP-IRAS) in combination with density-functional theory (DFT). A robust procedure is presented to determine the orientation of the FAA Molecules, which relies on the intensity ratios of vibrational bands only We show that even at deposition temperatures of 110 K, the PAA multilayer grows with a-Specific molecular, orientation; that is the PAA Molecular plane is preferentially aligned parallel with the MgO surface,. No change of molecular orientation occurs up to a temperature of 145 K Between 145 and 160 K, the film restructures adopting a nearly flat lying molecular Orientation. Between 170 and 205 K, the film undergoes a second structural transition to a crystalline phase. This transition is associated with a pronounced molecular reorientation. The molecules adopt a tilted orientation and, simultaneously, rotate around their C-2 axes The reorientation behavior Suggests that the molecular orientation in the crystalline phase is controlled by the interaction with the MgO(100) substrate. At higher temperature, no further restructuring is observed until the PAA. multilayer desorbs at temperatures above 230 K.

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APA:

Mohr, S., Xu, T., Döpper, T., Laurin, M., Görling, A., & Libuda, J. (2015). Molecular Orientation and Structural Transformations in Phthalic Anhydride Thin Films on MgO(100)/Ag(100). Langmuir, 31(28), 7806-7814. https://dx.doi.org/10.1021/acs.langmuir.5b01392

MLA:

Mohr, Susanne, et al. "Molecular Orientation and Structural Transformations in Phthalic Anhydride Thin Films on MgO(100)/Ag(100)." Langmuir 31.28 (2015): 7806-7814.

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