Spin-crossover behaviors in solvated cobalt(<scp>ii</scp>) compounds

Two solvated cobalt(II) terpyridine complexes, [Co(MeO-terpy)2](BF4)2&#183;H2O (1&#183;H2O) and [Co(MeO-terpy)2](BF4)2&#183;acetone (1&#183;acetone) were prepared. Annealing each of these complexes resulted in the formation of two desolvated species, 1 and 1′, respectively. 1&#183;H2O and 1 exhibited two-step and gradual SCO. The compound 1&#183;acetone has high-spin at all temperatures and 1′ undergoes a reverse spin transition due to a phase change.