Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

Abstract

A sugar-functionalized water-soluble tribenzotriquinacene derivative bearing six glucose residues, TBTQ-(OG) 6 , was synthesized and its interaction with C60 and C70-fullerene in co-organic solvents and aqueous solution was investigated by fluorescence spectroscopy and ultraviolet-visible spectroscopy. The association stoichiometry of the complexes TBTQ-(OG) 6 with C60 and TBTQ-(OG) 6 with C70 was found to be 1:1 with binding constants of K a = (1.50 ± 0.10) × 105 M−1 and K a = (2.20 ± 0.16) × 105 M−1, respectively. The binding affinity between TBTQ-(OG) 6 and C60 was further verified by Raman spectroscopy. The geometry of the complex of TBTQ-(OG) 6 with C60 deduced from DFT calculations indicates that the driving force of the complexation is mainly due to the hydrophobic effect and to host–guest π–π interactions. Hydrophobic surface simulations showed that TBTQ-(OG) 6 and C60 forms an amphiphilic supramolecular host–guest complex, which further assembles to microspheres with diameters of 0.3–3.5 μm, as determined by scanning electron microscopy.

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

“…Synthesis and characterization of host TBTQ-CB6. The host TBTQ-CB6 was synthesized starting from the known TBTQ-based hexakis(propargyl ether) 1 [ 29 ] ( Scheme 1a ). Through the CuAAC reaction with ethyl azidoacetate under Cu(I) catalysis, the TBTQ-based hexakis(ethyl acetate) compound 2 was obtained in 73% yield.…”

“…Over the past two decades, host–guest interactions and self-assembly based on TBTQ derivatives in organic media have been well established [ 22 – 27 ]. Recently, the host–guest chemistry of TBTQ derivatives in aqueous phase was also investigated by us [ 28 – 29 ]. In particular, a water-soluble TBTQ-based hexacarboxylate ( TBTQ-C 6 ) was prepared and bound with an azobenzene-containing amphiphile ( trans -AZO ) to produce the TBTQ-C 6 - trans -AZO supra-amphiphile by host–guest interactions in water.…”

Molecular bowls for inclusion complexation of toxic anticancer drug methotrexate

“…While TBTQ cavitands have mostly been explored for complexing fullerenes in organic media, 18 there are a handful of recent studies describing their inclusion complexation in water. 19 …”

Photo and pH Dual‐Responsive Supramolecular Vesicles Based on a Water‐Soluble Tribenzotriquinacene and an Azobenzene‐Containing Amphiphile in Water

“…In our previous report, a multiply sugar-functionalized water-soluble TBTQ derivative was synthesized and its hostguest chemistry with fullerenes in water was studied. [9] In the present work, we have designed and synthesized a new watersoluble TBTQ-based hexacarboxylate ( TBTQ-C 6 , or "H") as a host and an azobenzene-containing amphiphile (trans-AZO) as a guest to form the corresponding H � trans-AZO supraamphiphile by host-guest interactions in water. This supraamphiphile was further self-assembled to construct photo and pH dual-responsive supramolecular vesicles (Figure 1).…”