A @E02035@ or @S05970@, in which one atom or group in a @M03986@ is replaced by another atom or group. For example,
S06078-1.png
Source: PAC, 1994,
66, 1077. (
Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1169 [
Terms] [
Paper]