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Published on: August 1, 2018
Bent alkanes in a new thiourea-containing capsule
Ali Asadi1, Dariush Ajami, Julius Rebek
1The Skaggs Institute for Chemical Biology and Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA.
Journal of the American Chemical Society
|June 23, 2011
Summary
Researchers synthesized a cavitand with thiourea groups that dimerizes to form a wider capsule host. This host can encapsulate longer alkanes, like n-pentadecane, even when the guest molecule must fold to fit.
Area of Science:
- Supramolecular Chemistry
- Organic Synthesis
- Host-Guest Chemistry
Background:
- Cavitands are molecular hosts capable of encapsulating guest molecules.
- Thiourea moieties can participate in hydrogen bonding, influencing molecular recognition and self-assembly.
- Designing hosts with tunable cavity sizes is crucial for selective guest binding.
Purpose of the Study:
- To synthesize a novel cavitand incorporating thiourea hydrogen bonding sites.
- To investigate the dimerization of this cavitand and its ability to form capsule hosts.
- To explore the encapsulation of linear alkanes within the formed capsule.
Main Methods:
- Synthesis of a cavitand derivative.
- Dimerization studies in the presence of guest molecules.
- Nuclear Magnetic Resonance (NMR) spectroscopy for structural elucidation and guest conformation analysis.
Main Results:
- Successful synthesis of a cavitand with thiourea functionalities.
- Dimerization of the cavitand forms a capsule host with a larger cavity than urea or imide analogues.
- Encapsulation of n-pentadecane (n-C15H32) was achieved, with NMR data indicating the guest is folded within the capsule.
- The plasticity of thiourea hydrogen bonds facilitates stable complex formation despite guest contortion.
Conclusions:
- Thiourea-based cavitand dimerization offers a route to broader capsule hosts.
- The host exhibits plasticity, enabling the encapsulation of contorted guest molecules.
- This work expands the scope of supramolecular hosts for accommodating flexible guests.
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