Polarity of functional groups

Functional groups

Order of elution from a polar stationary phase, e.g. silica or aluminium oxide. (Very approximate!)

• Least polar (least retained)
• Chloride (-Cl)
• Alkane (-H)
• Ether (-OCH₃ )
• Nitro (-NO₂ )
• 3^o amine (-N(CH₃)₂ )
• Ketone (-COCH₃ )
• Ester (-OCOCH₃ )
• 1^o amine (-NH₂ )
• 2^o amide (-NHCOCH₃ )
• Alcohol (-OH )
• 1^o amide (-CONH₂ )
• Carboxylic acid (-COOH )
• Most polar (most retained)

Note: There is little correlation with substituent parameters such as Hammett constants or →group electronegativities