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Octahedral [Pd6L8]12+ metallosupramolecular cages: synthesis, structures and guest-encapsulation studies
journal contribution
posted on 2023-05-19, 13:55 authored by Kim, TY, Digal, L, Michael GardinerMichael Gardiner, Lucas, NT, Crowley, JDFour planar tripyridyl ligands (Ltripy), 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 [Pd6(Ltripy)8](BF4)12 octahedral cages (Ltripy=1 a, b or 2 a, b). The ligands and cages were characterized using a combination of 1H, 13C, 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 [Pd6(1 a, b)8]12+ cages were able to interact with three p-toluenesulfonate guest molecules while the larger [Pd6(2 a, 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).
History
Publication title
Chemistry: A European JournalVolume
23Issue
60Pagination
15089-15097ISSN
0947-6539Department/School
School of Natural SciencesPublisher
Wiley-V C H Verlag GmbhPlace of publication
Po Box 10 11 61, Weinheim, Germany, D-69451Rights statement
Copyright 2017 Wiley-VCH Verlag GmbH & Co. KGaA, WeinheimRepository Status
- Restricted