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

Co-crystal synthesis with 18-crown-6 with CoCl 2 in CH 3 CN and THF result in the formation of [Co(CH 3 CN) 4 (H 2 O) 2 (18-crown-6)][CoCl 3 (H 2 O)] 2 and [Co(H 2 O) 6 (18-crown-6) 2 (THF)][CoCl 4 ], respectively. The blue crystal of [Co(H 2 O) 6 (18-crown-6) 2 (THF)][CoCl 4 ] underwent a rare crystalline solid state reaction to form two new species with pink and blue crystals, CoCl 2 (H 2 O) 4 ⋅(H 2 O) and CoCl 3 (μ-Cl)Co(H 2 O) 5 (18-crown-6) 1.5 , respectively. Co-crystals of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) with CoCl 2 salts were synthesized in CH 3 CN and THF, resulting in the structural characterization of [Co(CH 3 CN) 4 (H 2 O) 2 (18-crown-6)][CoCl 3 (H 2 O)] 2 and [Co(H 2 O) 6 (18-crown-6) 2 (THF)][CoCl 4 ], respectively. Upon drying, the blue crystal of [Co(H 2 O) 6 (18-crown-6) 2 (THF)][CoCl 4 ] underwent a solid state reaction to form two new species with pink and blue crystals. The pink crystals were identified as CoCl 2 (H 2 O) 4 ⋅(H 2 O), and the blue crystals identified as CoCl 3 (μ-Cl)Co(H 2 O) 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.