Reaction of Cobalt(II) Chloride with 12-Crown-4 and 15-Crown-5 in the Presence of the closo-Decaborate Anion

The complexation reaction of cobalt(II) with 12-crown-4 and 15-crown-5 in the presence of the boron cluster anion [B10H10]2– has been studied. Initially, the complexation reaction was carried out in the (Et3NH)2[B10H10] + CoCl2 + 12-crown-4 system in an acetonitrile/water mixture. Crystals of compound (NHEt3)[Na(12-crown-4)2][CoCl4], suitable for X-ray diffraction analysis, were isolated from the reaction solution. The obtained compound does not contain the boron cluster anion, and cobalt is present as part of the anionic complex [CoCl4]2–, while the crown ether is not part of the coordination environment of cobalt(II). Upon the interaction of cobalt chloride with 15-crown-5 in the presence of the closo-decaborate salt, crystals of the complex [CoCl3(H2O)]2[Co(15-crown-5)(H2O)2]·4(15-crown-5) were isolated from the reaction solution, and their structure was determined by X-ray diffraction. The boron cluster anion does not participate in the complexation reaction and remains in the reaction solution. The target cobalt(II) complex was obtained in the absence of chloride ions by the reaction of the precursor [Co(DMF)6][B10H10] with the crown ether; the structure of complex [Co(15-crown-5)][B10H10]·CH3CN was determined by X-ray diffraction.