A @M03986@ (and the corresponding @CT01038@) able to provide a pair of electrons and thus capable of @C01329@ to a @L03508@, thereby producing a @L03510@.
Source: PAC, 1994,
66, 1077. (
Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1135 [
Terms] [
Paper]