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 灏綜D 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)]-灏綜D (灏緋sp) cavity, whereas inside the cationic heptakis(6-deoxy-6-amino)-灏綜D hydrochloride, MO flips once more, to adopt the same orientation as in 灏綜D. In the latter case the water solubility of MO is significantly lowered. The disposition of the guest in 灏綜D and in each 灏綜D derivative in a single mode was attributed principally to anti-parallel dipole-dipole stabilization. In the wider 绾珻D, 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)]-绾珻D, MO is positioned as in 灏緋sp, but a 1:2 adduct is also detected. Finally, MO does not dissolve in octakis(6-deoxy-6-amino)-绾珻D hydrochloride solution In the experiment, the researchers used many compounds, for example, Heptakis(6-Bromo-6-Deoxy)-灏?Cyclodextrin (cas: 53784-83-1Formula: C42H63Br7O28).
Heptakis(6-Bromo-6-Deoxy)-灏?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