Jiao Tifeng, Liu Minghua
CAS Key Laboratory of Colloid and Interface Science, Center for Molecular Science, Institute of Chemistry, CAS, Beijing 100080, People's Republic of China.
J Phys Chem B. 2005 Feb 24;109(7):2532-9. doi: 10.1021/jp045258g.
A bolaform Schiff base, N,N'-bis(salicylidene)-1,10-decanediamine (BSC10), has been synthesized and its interfacial hydrogen bond formation or molecular recognition with barbituric acid was investigated in comparison with that of a single chain Schiff base, 2-hydroxybenzaldehyde-octadecylamine (HBOA). It has been found that while HBOA formed a monolayer at the air/water interface, the bolaform Schiff base formed a multilayer film with ordered layer structure on water surface. When the Schiff bases were spread on the subphase containing barbituric acid, both of the Schiff bases could form hydrogen bonds with barbituric acid in situ in the spreading films. As a result, an increase of the molecular areas in the isotherms was observed. The in situ H-bonded films could be transferred onto solid substrates, and the transferred multilayer films were characterized by various methods such as UV-vis and FT-IR spectrosopies. Spectral changes were observed for the films deposited from the barbituric acid subphase, which supported the hydrogen bond formation between the Schiff bases and barbituric acid. By measuring the MS-TOF of the deposited films dissolved in CHCl3 solution, it was concluded that a 2:1 complex of HBOA with barbituric acid and a 1:2 complex of BSC10 with barbituric acid were formed. On the other hand, when the multilayer films of both Schiff bases were immersed in an aqueous solution of barbituric acid, a similar molecular recognition through the hydrogen bond occurred. A clear conformational change of the alkyl spacer in the bolaform Schiff base was observed during the complex formation with the barbituric acid.
合成了一种bola型席夫碱N,N'-双（水杨醛）-1,10-癸二胺（BSC10），并与单链席夫碱2-羟基苯甲醛十八胺（HBOA）相比较，研究了其与巴比妥酸的界面氢键形成或分子识别。研究发现，HBOA在空气/水界面形成单分子层，而bola型席夫碱在水面上形成具有有序层结构的多分子层膜。当席夫碱铺展在含有巴比妥酸的亚相上时，两种席夫碱在铺展膜中均可与巴比妥酸原位形成氢键。结果，在等温线上观察到分子面积增加。原位氢键结合膜可以转移到固体基质上，转移的多分子层膜通过紫外可见光谱和傅里叶变换红外光谱等各种方法进行表征。观察到从巴比妥酸亚相沉积的膜的光谱变化，这支持了席夫碱与巴比妥酸之间形成氢键。通过测量溶解在CHCl3溶液中的沉积膜的基质辅助激光解吸电离飞行时间质谱（MS-TOF），得出HBOA与巴比妥酸形成2:1配合物，BSC10与巴比妥酸形成1:2配合物的结论。另一方面，当两种席夫碱的多分子层膜浸入巴比妥酸水溶液中时，通过氢键发生了类似的分子识别。在与巴比妥酸形成配合物的过程中，观察到bola型席夫碱中烷基间隔基有明显的构象变化。
