Octahedral [Pd6L8]12+ Metallosupramolecular Cages: Synthesis, Structures and Guest-Encapsulation Studies
Octahedral [Pd6L8]12+ Metallosupramolecular Cages: Synthesis, Structures and Guest-Encapsulation Studies
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DOI：
10.1002/chem.201702518
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发表时间：
2017-10-26
影响因子：
4.3
通讯作者：
Crowley, James D.
中科院分区：
文献类型：
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作者：
Kim, Tae Y.;Digal, Lori;Crowley, James D.
四个平面三吡啶配体（L-tripy），1，3，5-tris（吡啶-3-基乙炔基）苯（3-吡啶基）苯基]苯2a和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1b和1，3，5-三[4-（三氟甲基）苯基]苯（3-己氧基-5-吡啶基）苯基]苯2B，并用于生成一族[Pd-6（L-tripy）（8）]（BF 4）（12）八面体笼（L-tripy=1a，B或2a，B）。使用H-1，C-13和DOSY核磁共振（NMR）光谱，高分辨率电喷雾质谱（HR-ESI-MS），红外（IR）光谱，元素分析，并在三种情况下，X射线晶体学的组合，其特征在于配体和笼。在二甲基亚砜（DMSO）中，用核磁共振光谱、质谱和分子模拟研究了笼与中性和阴离子客体的分子识别性能。没有观察到与简单的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，并且结合相互作用是尺寸选择性的。较小的[Pd-6（1a，B）（8）]（12+）笼能够与三个对甲苯磺酸客体分子相互作用，而较大的[Pd-6（2a，B）（8）]（12+）体系可以容纳四个阴离子客体分子。为了探讨疏水效应的重要性，使用混合水-DMSO（1：1）溶剂系统重新检查中性有机客体金刚烷、蒽、芘和1，8-萘酰亚胺在笼内的结合。在该溶剂系统中，观察到除金刚烷外的所有客体都结合在笼的空腔内。NMR光谱和分子建模表明，笼结合多个副本的个别客人（3-6个客人分子之间的笼）。
Four planar tripyridyl ligands (L-tripy), 1,3,5-tris(pyridin-3-ylethynyl)benzene 1a, 1,3,5-tris[4-(3-pyridyl)phenyl]benzene 2a, and the hexyloxy chain functionalized derivatives 1,3,5-tris[(3-hexyloxy-5-pyridyl)ethynyl]benzene 1b, and 1,3,5-tris[4-(3-hexyloxy-5-pyridyl)phenyl]benzene 2b, were synthesized and used to generate a family of [Pd-6(L-tripy)(8)](BF4)(12) octahedral cages (L-tripy=1a,b or 2a,b). The ligands and cages were characterized using a combination of H-1, C-13, 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-6(1a,b)(8)](12+) cages were able to interact with three p-toluenesulfonate guest molecules while the larger [Pd-6(2a,b)(8)](12+) 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).