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Ultra-Fast Molecular Rotors within Porous Organic Cages.

ABSTRACT: Using variable temperature ² H static NMR spectra and ¹³ C spin-lattice relaxation times (T₁ ), we show that two different porous organic cages with tubular architectures are ultra-fast molecular rotors. The central para-phenylene rings that frame the "windows" to the cage voids display very rapid rotational rates of the order of 1.2-8×10⁶ ?Hz at 230?K with low activation energy barriers in the 12-18?kJ?mol^-1 range. These cages act as hosts to iodine guest molecules, which dramatically slows down the rotational rates of the phenylene groups (5-10×10⁴ ?Hz at 230?K), demonstrating potential use in applications that require molecular capture and release.

SUBMITTER: Hughes AR

PROVIDER: S-EPMC5813266 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature

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Ultra-Fast Molecular Rotors within Porous Organic Cages.

Hughes Ashlea R AR Brownbill Nick J NJ Lalek Rachel C RC Briggs Michael E ME Slater Anna G AG Cooper Andrew I AI Blanc Frédéric F

Chemistry (Weinheim an der Bergstrasse, Germany) 20171122 68

Using variable temperature 2 H static NMR spectra and 13 C spin-lattice relaxation times (T1 ), we show that two different porous organic cages with tubular architectures are ultra-fast molecular rotors. The central para-phenylene rings that frame the "windows" to the cage voids display very rapid rotational rates of the order of 1.2-8×106 Hz at 230 K with low activation energy barriers in the 12-18 kJ mol-1 range. These cages act as hosts ...[more]

PMID: 29053892

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