A type of molecular magnetism that is the result of electronic instability (see
electronic stability) caused by external constraints (temperature, pressure, or electromagnetic radiation),
which induce structural changes at molecular and lattice levels. The phenomenon is
most characteristic of first-row transition metal complexes,
e g,. those of
FeII.
An example of spin-crossover complexes (the term of spin-state isomers is also used)
is
[Fe(2-pic)3]Cl2·EtOH
(2-pic = 2-picolylamine).
At the
Fe–
N
distance of
(
),
the complex has an electronic
low-spin state (
1A
1), whereas stretching the bond up to
at
induces the transition to a
high-spin state (
5T
2).
Source:
Cite as:
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.
