Ligand-Structure Effect on the Formation of One-Dimensional Nanoscale Cu(II)-Schiff Base Complexes and Solvent-Mediated Shape Transformation

Abstract

We report here a Cu(II)-Schiff base complex that can assemble into one-dimensional (1D) nanoscale fibers, belts, and rods under different synthetic conditions. The ligand-structure effect is investigated by modification of the ligand structure. The formation of a 1D nanostructure was studied, and the formation of dimers was revealed as a key factor for 1D assembly. In dimethylformamide (DMF) medium, this complex represents one of the rare examples of low-molecular-weight “super-metallogelators” with a critical gelation concentration of 0.3 wt % for DMF. The ligand exhibits good selectivity toward different metal ions in terms of gel formation and only the Cu(II) complex forms gels. It is interesting that this metallogel is a kind of dynamic nanostructure, which can be transformed to rods with different aspect ratios via a solvent-mediated process under stimulation of ultrasound.