The interface bonding and orientation of a quinonoid zwitterion
The interface bonding and orientation of a quinonoid zwitterion
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DOI：
10.1039/c003996a
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发表时间：
2010-01-01
影响因子：
3.3
通讯作者：
Dowben, Peter A.
中科院分区：
文献类型：
--
作者：
Xiao, Jie;Zhang, Zhengzheng;Dowben, Peter A.
我们已经研究了强偶极两性离子p-benzoquinonoimine型分子的相互作用和取向，与一个大的固有偶极子的10德拜，在导电和极性绝缘基板上。具体地，我们在金和铁电锂氧化物表面上沉积（6 Z）-4-（丁基氨基）-6-（丁基亚氨基）-3-氧代环己-1，4-二烯-1-醇C6 H2（中心点中心点NHR）（2）（中心点中心点O-2，其中R = n-C4 H9）。已观察到的两性离子吸附质的瞬态和静态电偶极子的影响。对于在金上的吸附，我们发现分子通过氮原子键合到表面，形成厚度在1 nm范围内保持相当均匀的膜。这种两性离子化合物从绝缘的溶液中的吸附，周期性极化的铁电锂铁酸盐基板上，表现出优先吸附的一种类型的铁电域。对于金和锂离子酸盐基底，两性离子选择性取向，其“C-6核”的平面沿着表面法线。这种简化的几何形状的强偶极子排列提供了一个对称性的简化，允许更好地识别的振动模式，负责弗兰克-康登散射中揭示的光电子发射光谱中的精细光谱特征。
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 C6H2(center dot center dot center dot NHR)(2)(center dot center dot center dot O-2 where R = n-C4H9, 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.