Effect of modulator ligands on the growth of Co2(dobdc) nanorods

Control over the size, shape, uniformity, and external surface chemistry of metal-organic framework nanocrystals is important for a wide range of applications. Here, we investigate how monotopic modulators that mimic the coordination mode of native bridging ligands affect the growth of anisotropic Co-2(dobdc) (dobdc(4-) = 2,5-dihydroxy-1,4-benzenedicarboxylic acid) nanorods. Through a combination of transmission electron microscopy (TEM) and nuclear magnetic resonance spectroscopy (NMR) studies, nanorod diameter was found to be strongly correlated to the acidity of the modulator and to the degree of modulator incorporation into the nanorod structure. Notably, highly acidic modulators allowed for the preparation of sub-10 nm nanorods, a previously elusive size regime for the M-2(dobdc) family. More broadly, this study provides new insights into the mechanism of modulated growth of metal-organic framework nanoparticles.

Automated summary

Control over the size, shape, uniformity, and external surface chemistry of metal-organic framework nanocrystals is crucial for various applications. In this study, the growth of anisotropic Co-2(dobdc) nanorods was investigated in the presence of monotopic modulators. The results showed that the nanorod diameter was strongly influenced by the acidity of the modulator and its incorporation into the nanorod structure. The study also achieved the preparation of sub-10 nm nanorods, which was previously difficult for the M-2(dobdc) family.