An atom or group which, when added to or introduced into a chromophore
, causes a bathochromic shift and/or a hyperchromic effect
in a given band of the chromophore
, usually in that of lowest frequency. This term is obsolete.
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2229