Solid state structural characterization and solution spectroscopy of a dodecyloxy copper nanoball

The synthesis and properties of discrete nanometer scale materials is of critical importance for the development of advanced nanoscale materials. Here we report the solid structural characterization and solution photophysical properties of self-assembled [Cu₂(OC₁₂-bdc)₂ L₂]₁₂ [(OC₁₂-bdc)^2- = 5-(dodecyloxy)-1,3-benzenedicarboxylate; L = solvent] nanoballs (hereafter OC₁₂-nanoball or OC₁₂-NB). The crystal packing reveals that selected OC₁₂ moieties thread through the windows of adjacent OC₁₂-NB molecules and thereby sustain a 1-fold diamondoid network. Unlike other NBs the OC₁₂-NBs are readily soluble in a variety of hydrocarbon solvents including benzene, toluene, and hexane. The solution properties of the OC₁₂-NB were examined in toluene using optical absorption, and both steady-state and time-resolved fluorescence methods. These results indicate that the electronic properties of the OC₁₂-NB are similar to those of the OH-nanoball previously examined (Larsenet al.Inorg. Chem. 2007, 46 (5), 5904 -5910). In addition, fluorescence polarization results further indicate that the OC₁₂-NBs remain intact in both toluene and hexane solutions. Overall, these data suggest a general stability for Cu(II) NBs containing a variety of substituted isophthalic acid ligands in solution.