Spin-crossover behaviors in solvated cobalt(II) compounds

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