Hydrogen-Bonded Anionic Host Lattices Constructed with Isocyanurate and Thiourea/Urea
journal contributionposted on 03.02.2016, 00:00 by Chi-Keung Lam, Sam Chun-Kit Hau, Chung-Wah Yau, Thomas C. W. Mak
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A series of seven inclusion complexes containing the isocyanurate ion, thiourea/urea, and selected quaternary ammonium ions as templates, namely, (CH3)4N+C3H2N3O3–· 3(NH2)2CS·H2O (1), (CH3)4N+C3H2N3O3–·(NH2)2CS (2), (C2H5)4N+C3H2N3O3–·(NH2)2CS (3), (n-C3H7)4N+C3H2N3O3–·(NH2)2CS·H2O (4), 3[(n-C4H9)4N+C3H2N3O3–]·5(NH2)2CS·3H2O (5), (C2H5)4N+C3H2N3O3–·(NH2)2CO (6) and (n-C3H7)4N+C3H2N3O3–·2(NH2)2CO·H2O (7), have been prepared and characterized by X-ray crystallography. Complex (1) features a hydrogen-bonded molecular cage in which two (CH3)4N+ cations can be accommodated. Complexes (2) and (7) are channel-type inclusion compounds. In (2), the thiourea sulfur atom does not participate in host lattice construction, while (7) contains several intersecting channel systems that are formed by the cross-linkage of two sets of isocyanurate–urea–water ribbons. Complexes (3)–(6) exhibit layer-type architectures. The host layers of complexes (3) and (6) are constructed by two distinct rosette motifs produced by isocyanurate ion and thiourea/urea in a ratio of 2:1 and 1:2, respectively. The isocyanurate–thiourea–water (1:1:1) ribbons are cross-linked together to generate the host framework of complex (4), while a new type of supramolecular rosette ribbon is identified in complex (5).