was added followed by 20 min of sonication. The solution became transparent immediately upon the addition of the ligand. For purification, the nanoparticles were precipitated by adding 10 mL of hexane (a mixture of isomers) and centrifuged at 5000 rcf for 5 min. The supernatant was then discarded, and the solid residue was redispersed in 1 mL of toluene.