Two or more molecular entities
are described as isoelectronic if they have the same number of valence
electrons and the same structure, i.e. number and connectivity
of atoms, but differ in some of the elements involved. Thus: CO
are isoelectronic. CH2=C=O
are isoelectronic. CH3COCH3
have the same number of electrons, but have different structures, hence they are
not described as isoelectronic.
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1128
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook