To assess the versatility of this reaction, we performed peroxide-mediated functionalization of SWCNT using five different aryl diazonium salts with various Hammett substituent constants (Figure ). The Hammett substituent constant is an indicator of the electron donating or withdrawing nature of the substituents of an aromatic ring and is a useful factor in predicting the electronic properties of aryl diazonium salts and their corresponding defects, including reduction potential and defect emission wavelength. As shown in Figure , all five aryl molecules successfully conjugated to the nanotube surface, generating emissive peaks at wavelengths correlating with the Hammett substituent constant. This trend is in good agreement with previously generated aryl-functionalized CCNTs. The exact values of the E11 -peak positions are listed in Table . The concentration of each aryl diazonium salt needed to achieve optimal functionalization (as listed in Table ) varied depending on their substituents. No clear correlation was observed between the Hammett substituent constant of a diazonium salt with the concentration necessary for functionalization, and so this variation likely depends upon other factors such as solubility and stability of the diazonium compounds.