Crystalline solid state reactivity and solvent effects in cobalt chloride salts with 18-crown-6

Co-crystals of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) with CoCl2 salts were synthesized in CH3CN and THF, resulting in the structural characterization of [Co(CH3CN)4(H2O)2(18-crown-6)][CoCl3(H2O)]2 and [Co (H2O)6(18-crown-6)2(THF)][CoCl4], respectively. Upon drying, the blue crystal of [Co(H2O)6(18-crown-6)2(THF)][CoCl4] underwent a solid state reaction to form two new species with pink and blue crystals. The pink crystals were identified as CoCl2(H2O)4 & sdot;(H2O), and the blue crystals identified as CoCl3(mu-Cl)Co(H2O)5(18-crown-6)1.5 with a bridging Cl atom. These structures highlight the effect that solvent has on packing, cell volumes, and hydrogen bonding networks, and demonstrate a rare example of a solid state crystalline reaction.