Kim Tae Y, Digal Lori, Gardiner Michael G, Lucas Nigel T, Crowley James D
Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.
School of Physical Sciences (Chemistry), University of Tasmania, Hobart, Australia.
Chemistry. 2017 Oct 26;23(60):15089-15097. doi: 10.1002/chem.201702518. Epub 2017 Oct 5.
Four planar tripyridyl ligands (L ), 1,3,5-tris(pyridin-3-ylethynyl)benzene 1 a, 1,3,5-tris[4-(3-pyridyl)phenyl]benzene 2 a, and the hexyloxy chain functionalized derivatives 1,3,5-tris[(3-hexyloxy-5-pyridyl)ethynyl]benzene 1 b, and 1,3,5-tris[4-(3-hexyloxy-5-pyridyl)phenyl]benzene 2 b, were synthesized and used to generate a family of Pd (L ) octahedral cages (L =1 a, b or 2 a, b). The ligands and cages were characterized using a combination of H, C, and DOSY nuclear magnetic resonance (NMR) spectroscopy, high resolution electrospray mass spectrometry (HR-ESI-MS), infrared (IR) spectroscopy, elemental analysis, and in three cases, X-ray crystallography. The molecular recognition properties of the cages with neutral and anionic guests were examined, in dimethyl sulfoxide (DMSO), using NMR spectroscopy, mass spectrometry and molecular modeling. No binding was observed with simple aliphatic and aromatic guest molecules. However, anionic sulfonates were found to interact with the octahedral cages and the binding interaction was size selective. The smaller [Pd (1 a, b) ] cages were able to interact with three p-toluenesulfonate guest molecules while the larger [Pd (2 a, b) ] systems could host four of the anionic guest molecules. To probe the importance of the hydrophobic effect, a mixed water-DMSO (1:1) solvent system was used to reexamine the binding of the neutral organic guests adamantane, anthracene, pyrene and 1,8-naphthalimide within the cages. In this solvent system all the guests except adamantane were observed to bind within the cavities of the cages. NMR spectroscopy and molecular modeling indicated that the cages bind multiple copies of the individual guests (between 3-6 guest molecules per cage).
合成了四种平面三吡啶配体（L），即1,3,5-三（吡啶-3-基乙炔基）苯1 a、1,3,5-三[4-（3-吡啶基）苯基]苯2 a，以及己氧基链官能化衍生物1,3,5-三[（3-己氧基-5-吡啶基）乙炔基]苯1 b和1,3,5-三[4-（3-己氧基-5-吡啶基）苯基]苯2 b，并用于生成一系列[Pd（L）]（BF）八面体笼（L = 1 a、b或2 a、b）。使用¹H、¹³C和扩散排序核磁共振（DOSY NMR）光谱、高分辨率电喷雾质谱（HR-ESI-MS）、红外（IR）光谱、元素分析等方法对配体和笼进行了表征，在三种情况下还进行了X射线晶体学分析。在二甲基亚砜（DMSO）中，使用核磁共振光谱、质谱和分子建模研究了笼与中性和阴离子客体的分子识别特性。未观察到与简单脂肪族和芳香族客体分子的结合。然而，发现阴离子磺酸盐与八面体笼相互作用，且结合相互作用具有尺寸选择性。较小的[Pd（1 a、b）]笼能够与三个对甲苯磺酸盐客体分子相互作用，而较大的[Pd（2 a、b）]体系可以容纳四个阴离子客体分子。为了探究疏水效应的重要性，使用混合水-DMSO（1:1）溶剂体系重新研究了笼内中性有机客体金刚烷、蒽、芘和1,8-萘二甲酰亚胺的结合情况。在该溶剂体系中，观察到除金刚烷外的所有客体都在笼腔内结合。核磁共振光谱和分子建模表明，笼结合多个单个客体分子（每个笼3 - 6个客体分子）。
