Slow magnetic relaxation and spin crossover behavior in two mixed-valence Co(ii)/Co(iii) complexes

Two mixed-valence Co(II)/Co(III) complexes of [Co-II(phen)(3)][Co-III(HATD)(2)](2).3DMA.3.5H(2)O (1), and [CoII(terpy)(2)][Co-III(HATD)(2)](2).4DMA.H2O (2), (phen = 1,10-phenanthroline, terpy = 2,2':6',2-terpyridine, H(3)ATD = azotetrazolyl-2,7-dihydroxynaphthalene, DMA = N,N-dimethylacetamide) were synthesized and their crystal structures were characterized. Crystal structure analyses reveal that complexes 1 and 2 consist of CoIII and CoII ions in an octahedral environment where the CoII ion is coordinated by three phen ligands and two terpy ligands, respectively. Magnetic measurements show that complex 1 displays field induced single-molecule magnet behavior, whereas 2 undergoes a gradual thermal spin crossover (SCO).

Automated summary

Two mixed-valence Co(II)/Co(III) complexes were synthesized and characterized by crystal structure analysis. The complexes consist of CoIII and CoII ions in an octahedral environment and exhibit different magnetic behaviors.