## Abstract

The binary metallo-β-cyclodextrins formed by 6 ^{A}-(2-(2-(2-aminoethylamino)ethylamino)ethylamino)-6 ^{A}-deoxy-β-cyclodextrin, [M(βCDtrien)] ^{2+}, where M ^{2+} = Ni ^{2+}, Cu ^{2+} and Zn ^{2+}, are characterized by log(K/dm ^{3} mol ^{-1}) = 11.50±0.02,10.70±0.07 and 9.40±0.01, respectively, in aqueous solution at 298.2 K and I = 0.1 mol dm ^{-3} (NaClO _{4}), where K is the stability constant. For those formed by 6 ^{A}-deoxy-6 ^{A}-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin, [M(βCDcyclen)] ^{2+}, where M ^{2+} = Cu ^{2+} and Zn ^{2+}, log(K/dm ^{3} mol ^{-1}) = 13.6±0.02 and 11.62±0.04, respectively. The ternary metallo-β-cyclodextrins formed by [M(βCDtrien)] ^{2+} and (R)- and (S)-tryptophanate, [M(βCDtrien)((R)-Trp)] ^{+} and [M(βCDtrien)((S)-Trp)] ^{+} are characterized by log(K/dm ^{3} mol ^{-1}) = 6.90±0.04 and 6.79±0.04, 8.2±0.3 and 7.9±0.2, and 6.64±0.08 and 7.01±0.07, respectively, where M ^{2+} = Ni ^{2+}, Cu ^{2+} and Zn ^{2+}. For the ternary metallo-β-cyclodextrins formed by [M(βCDcyclen)] ^{2+} and (R)- and (S)-tryptophanate, [M(βCDcyclen)((R)-Trp)] ^{+} and [M(βCDcyclen)((S)-Trp)] ^{+}, log(K/dm ^{3} mol ^{-1}) = 6.84±0.06 and 6.85±0.06, and 4.95±0.05 and 4.94±0.04, respectively, where M ^{2+} = Cu ^{2+} and Zn ^{2+}. Other binary and ternary metallo-β-cyclodextrins are also formed. Binary complexes formed by the substituted β-cyclodextrins are exemplified by βCDcyclen (R)-Trp ^{-} and βCDcyclen (S)-Trp ^{-} for which log(K/dm ^{3} mol ^{-1}) = 3.69±0.04 and 3.95±0.03, respectively. These data are discussed together with those from the literature characterizing other metallo-β-cyclodextrin and substituted β-cyclodextrin systems.

Original language | English |
---|---|

Pages (from-to) | 375-381 |

Number of pages | 7 |

Journal | Australian Journal of Chemistry |

Volume | 53 |

Issue number | 5 |

DOIs | |

Publication status | Published - 1 Dec 2000 |

Externally published | Yes |

## Keywords

- Copper
- Cyclodextrin
- Nickel
- Stability constant
- Tryptophan
- Tryptophanate
- Zinc

## Fingerprint

Dive into the research topics of 'Metallo-β-cyclodextrins of 6^{A}-(2-(2-(2-Aminoethylamino)-ethylamino)ethylamino)-6

^{A}-deoxy-β-cyclodextrin 6

^{A}-Deoxy-6

^{A}-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin: Their formation and complexation of (R)- and (S)-tryptophan and tryptophanate in aqueous solution'. Together they form a unique fingerprint.