Pb(ii) metal–organic nanotubes based on cyclodextrins: biphasic synthesis, structures and properties

Two chiral lead metal–organic nanotubes (CD-MONT-2 and CD-MONT-3) based on β-cyclodextrin (β-CD) and γ-cyclodextrin (γ-CD) were synthesized through a biphasic solvothermal reaction. The lead ions were connected by two β-CD or γ-CD molecules through their glycosidic oxygen atoms to generate a discrete metal–organic nanotube containing a {Pb14} or {Pb16} metallamacrocycle, respectively. Guest solvents of cyclohexanol molecules were trapped in the cavity of the β-CD-based nanotube, whereas there were no solvents in the cavity of the γ-CD-based nanotube. These differences directly led to the formation of different 3D packing structures. Their properties including temperature-dependent photoluminescence, adsorption of I2 molecules and thermal-decomposition behaviors were studied.