QSAR & QSPR

E sValues for Various SubstituentsH Me Pr t-Bu F Cl Br OH SH NO 2C 6H 5CN NH 20.0 -1.24 -1.60 -2.78 -0.46 -0.97 -1.16 -0.55 -1.07 -2.52 -3.82 -0.51 -0.61Compare some extreme values:H 0.00 the reference substituent in the Taft equationMe -1.24: little steric resistance to hydrolysist-Bu -2.78 : large resistance to hydrolysisNote: H is usually used as the reference substituent (E s(0)), but sometimes when another group,such as methyl (Me) is used as the reference, as in the chemical equation above, the valuebecomes 1.24.