Influence of Host’s Substitution on the Orientation of the Guest: Pseudo-rotaxanes of Charged Cyclodextrins with Methyl Orange in Solution was written by Mourtzis, Nikolaos;Eliadou, Kyriaki;Yannakopoulou, Konstantina. And the article was included in Supramolecular Chemistry in 2004.Formula: C42H63Br7O28 This article mentions the following:
Methyl orange (MO), an azo-dye mol. with an inherent dipole moment, has been used as a probe to explore the influence of anionic or cationic substituents of cyclodextrins (CDs) on the mode of insertion to form pseudorotaxanes, using NMR spectroscopy. MO is oriented in a single mode inside the βCD cavity, with the dimethylamino group localized at the secondary side. This orientation is completely reversed when MO enters the anionic sodium heptakis[6-deoxy-6-(3-thiopropionate)]-βCD (βpsp) cavity, whereas inside the cationic heptakis(6-deoxy-6-amino)-βCD hydrochloride, MO flips once more, to adopt the same orientation as in βCD. In the latter case the water solubility of MO is significantly lowered. The disposition of the guest in βCD and in each βCD derivative in a single mode was attributed principally to anti-parallel dipole-dipole stabilization. In the wider γCD, the availability of more cavity space leads to 1:2 and 2:2 host/guest stoichiometries and the effect of dipoles is of secondary significance. In the anionic sodium octakis[6-deoxy-6-(3-thiopropionate)]-γCD, MO is positioned as in βpsp, but a 1:2 adduct is also detected. Finally, MO does not dissolve in octakis(6-deoxy-6-amino)-γCD hydrochloride solution In the experiment, the researchers used many compounds, for example, Heptakis(6-Bromo-6-Deoxy)-β-Cyclodextrin (cas: 53784-83-1Formula: C42H63Br7O28).
Heptakis(6-Bromo-6-Deoxy)-β-Cyclodextrin (cas: 53784-83-1) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. When the molecular ion is detected, the bromine and chlorine isotope patterns are very distinct, but caution is to be exercised for certain mixed chlorinated/brominated compounds, which can look similar to homohalogen patterns.Formula: C42H63Br7O28
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary