title: The interface bonding and orientation of a quinonoid zwitterion.
abstract: We have investigated the interaction and orientation of a strongly dipolar zwitterionic p-benzoquinonemonoimine-type molecule, with a large intrinsic dipole of 10 Debye, on both conducting and on polar insulating substrates. Specifically, we deposited (6Z)-4-(butylamino)-6-(butyliminio)-3-oxocyclohexa-1,4-dien-1-olate C(6)H(2)([horiz bar, triple dot above]NHR)(2)([horiz bar, triple dot above]O)(2) where R = n-C(4)H(9), on both gold and ferroelectric lithium niobate surfaces. An influence of both transient and static electric dipoles on the zwitterionic adsorbate has been observed. For adsorption on gold, we find that the molecule bonds to the surface through the nitrogen atoms, forming films that remain fairly uniform down to thicknesses in the 1 nm range. Adsorption of this zwitterionic compound from solution on insulating, periodically poled ferroelectric lithium niobate substrates, showed preferential adsorption on one type of ferroelectric domain. For both gold and the lithium niobate substrates, the zwitterion adopts a preferential orientation with the plane of its "C(6) core" along the surface normal. This simplified geometry of strong dipole alignment provides a symmetry simplification allowing better identification of the vibrational modes responsible for Frank-Condon scattering revealed in the fine spectroscopic signature in the photoemission spectrum.
authors.affiliation: Dept. of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiao
authors.forename: Zhengzheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.forename: Lucie
authors.initials: L
authors.lastname: Routaboul
authors.forename: Pierre
authors.initials: P
authors.lastname: Braunstein
authors.forename: Bernard
authors.initials: B
authors.lastname: Doudin
authors.forename: Yaroslav B
authors.initials: YB
authors.lastname: Losovyj
authors.forename: Orhan
authors.initials: O
authors.lastname: Kizilkaya
authors.forename: Luis G
authors.initials: LG
authors.lastname: Rosa
authors.forename: Camelia N
authors.initials: CN
authors.lastname: Borca
authors.forename: Alexei
authors.initials: A
authors.lastname: Gruverman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Dowben