Crystal structures of
1Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China.
Abstract:
The crystal structures of [18]aneN(6)H(2)K[Co(CN)(6)].4H(2)O [potassium dihydrogen hexacyanocobaltate-1,4,7,10,13,16-hexaazacyclooctadecane-water (1/1/4)], [16]aneN(4)H(2)K[Co(CN)(6)] [potassium dihydrogen hexacyanocobaltate-1,5,9,13-tetraazacyclohexadecane (1/1)] and [12]aneN(4)H(3)[Co(CN)(6)].2H(2)O [trihydrogen hexacyanocobaltate-1,4,7,10-tetraazacyclododecane-water (1/1/2)] have been determined. For these supercomplexes, the [Co(CN)(6)](3-) binding with protonated polyammonium macrocycles is dominant in the binding competition between K(+) and [Co(CN)(6)](3-). It is suggested that the binding of [Co(CN)(6)](3-) with protonated polyammonium macrocycles is independent of the cavity size of the macrocycle, whereas that of K(+) is size-match selective. For [18]aneN(6)H(2)K[Co(CN)(6)].4H(2)O, the formation of a two-dimensional lamella may be derived from a chain-like arrangement of four-, five- and eight-membered rings in the network through the mutual balance between electrostatic and hydrogen-bonding interactions. [16]aneN(4)H(2)K[Co(CN)(6)] is a novel example demonstrating the anchoring of cobalticyanide through hydrogen-bonding interactions inside a zeolite-type cavity in the three-dimensional network formed by K(+) and the macrocycles through Coulombic interactions. Also, a three-dimensional network was formed mainly through hydrogen-bonding interactions between [Co(CN)(6)](3-), protonated macrocycles and water molecules in [12]aneN(4)H(3)[Co(CN)(6)].2H(2)O.
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