### Abstract

Language | English |
---|---|

Pages | 323-326 |

Number of pages | 3 |

Journal | Journal of Chemical and Engineering Data |

Volume | 54 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2009 |

### Fingerprint

### Keywords

- cucurbit[n]urils
- diffusion coefficient

### Cite this

*Journal of Chemical and Engineering Data*,

*54*(2), 323-326. https://doi.org/10.1021/je800347u

}

*Journal of Chemical and Engineering Data*, vol. 54, no. 2, pp. 323-326. https://doi.org/10.1021/je800347u

**Diffusion coefficient of cucurbit[n]urils (n = 6 or 7) at different concentrations, temperatures and pH.** / Grant, M.; Wheate, Nial J.; Aldrich-Wright, Janice R.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Diffusion coefficient of cucurbit[n]urils (n = 6 or 7) at different concentrations, temperatures and pH

AU - Grant, M.

AU - Wheate, Nial J.

AU - Aldrich-Wright, Janice R.

PY - 2009

Y1 - 2009

N2 - The diffusion coefficient of cucurbit[6]uril (CB[6]) and cucurbit[7]uril (CB[7]) was determined using pulsed gradient spin−echo nuclear magnetic resonance spectroscopy. Both CB[6] and CB[7] diffuse faster through H2O than D2O with increasing temperature, consistent with the Stokes−Einstein equation where diffusion is proportional to temperature divided by viscosity. The activation energy (EA) was also determined and is larger for CB[n] in 90 % H2O/10 % D2O v/v than in D2O. Both compounds aggregate with increasing concentration between (0.25 and 2)·10−3 mol·L−1. The pH of the solution does not significantly affect the diffusion coefficient of CB[6] and CB[7], except at very low pH where protonation of the carbonyl groups induces aggregation, which slows their rate of diffusion.

AB - The diffusion coefficient of cucurbit[6]uril (CB[6]) and cucurbit[7]uril (CB[7]) was determined using pulsed gradient spin−echo nuclear magnetic resonance spectroscopy. Both CB[6] and CB[7] diffuse faster through H2O than D2O with increasing temperature, consistent with the Stokes−Einstein equation where diffusion is proportional to temperature divided by viscosity. The activation energy (EA) was also determined and is larger for CB[n] in 90 % H2O/10 % D2O v/v than in D2O. Both compounds aggregate with increasing concentration between (0.25 and 2)·10−3 mol·L−1. The pH of the solution does not significantly affect the diffusion coefficient of CB[6] and CB[7], except at very low pH where protonation of the carbonyl groups induces aggregation, which slows their rate of diffusion.

KW - cucurbit[n]urils

KW - diffusion coefficient

U2 - 10.1021/je800347u

DO - 10.1021/je800347u

M3 - Article

VL - 54

SP - 323

EP - 326

JO - Journal of Chemical and Engineering Data

T2 - Journal of Chemical and Engineering Data

JF - Journal of Chemical and Engineering Data

SN - 0021-9568

IS - 2

ER -