Compound [Co(4-terpyridone)2](CF3SO3)2·1H2O, where 4-terpyridone is 2,6-bis(2-pyridyl)-4(1H)-pyridone, forms two polymorphs. Polymorph 1 displays a continuous spin conversion in the temperature region 300–120 K while polymorph 2 shows, on cooling, the onset of a continuous high-spin (HS) to low-spin (LS) conversion interrupted by an abrupt “reverse” spin transition in the temperature region 217–203 K. The formed unstable HS intermediate phase (IP) undergoes a strong cooperative “normal” spin transition characterised by a hysteresis loop 33 K wide. The structural data give support for a crystallographic phase transition, which takes place concomitantly with the “reverse” spin state transition.
You have access to this article
Please wait while we load your content...
Something went wrong. Try again?