Figure 13.

Synthesis of TSUA- and BPDB-modified MCM-41.

Notes: Two approaches to the operation and function of the AB-modified MCM-41 NPs carrying nanovalves. Py-β-CD or β-CD threads onto the trans-AB stalks to seal the nanopores. Upon irradiation (351 nm), the isomerization of AB units from trans to cis leads to the dissociation of Py-β-CD or β-CD rings from the stalks, thus opening the gates to the nanopores and releasing the cargo. Reprinted with permission from Ferris DP, Zhao YL, Khashab NM, Khatib HA, Stoddart JF, Zink JI. Light-operated mechanized nanoparticles. J Am Chem Soc. 2009;131(5):1686–1688. Copyright 2009 American Chemical Society.⁴²

Abbreviations: TSUA, 4-(3-triethoxysilylpropylureido) azobenzene; BPDP, (E)-4-((4-(benzylcarbamoyl)phenyl)diazenyl) benzoic acid; β-CD, β-cyclodextrin; AB, azobenzene, NP, nanoparticle; THF, tetrahydro furan; RT, room temperature; PhMe, toluene.