Also contains definition of: direct effect
An experimentally observable effect symbolized by \(F\) (on reaction rates, etc.) of @I03130@ coulombic interaction between the centre of interest and a remote unipole or dipole, by direct action through space rather than through bonds. The magnitude of the field effect (or 'direct effect') depends on the unipolar charge/@D01761@, orientation of dipole, shortest distance between the centre of interest and the remote unipole or dipole, and on the effective @D01697@.
See also:
electronic effect
inductive effect
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1115 [Terms] [Paper]