Anionic Host Layers Constructed with Guanidinium–Hydrogen Carbonate Dimer 2:1 Rosette-Ribbons and Bridging Carboxylate Connectors

• Published in: Crystal growth & design Vol. 12; no. 9; pp. 4457 - 4465
• Main Authors: Han, Jie, Yau, Chung-Wah, Chan, Chin Wing, Mak, Thomas C. W
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 05.09.2012
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Cobalt oxide; Imidazole derivatives; Pillared structure; Hydrogen 1; Monocrystals; Imidazoles; Hydrogen bonds; Cross-linking; Inclusion compounds; Cyclohexane; Dimers; Carbonates; Arrays; Carboxylates; Centrosymmetrical crystals; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg3006184

Four new inclusion compounds featuring an anionic layer-type host lattice constructed with guanidinium–bis(hydrogen carbonate) 2:1 rosette-ribbons that accommodate the same tetra-n-butylammonium guest species have been obtained and characterized by single-crystal X-ray analysis. In these crystal structures, an array of rosette-ribbons in parallel or nearly parallel alignment are cross-linked by selected carboxylate molecular connectors with effective bridging distances in the range 10.1–19.8 Å: 4,4′-biphenyldicarboxylate, with the longest separation between its colinear hydrogen-bonding acceptor sites in [(n-Bu)4N+]6[C(NH2)3 +]6(HCO3 –)6[4,4′-C12H8(COO–)2]3·6H2O (1); cyclohexane-1,4-dicarboxylate, with a nonplanar molecular skeleton in [(n-Bu)4N+]4[C(NH2)3 +]8(HCO3 –)6[1,4′-C6H10(COO–)2]3·8H2O (2); 4-cyanobenzoate, with a strong “Y type” hydrogen-bonding acceptor site at one end and a weak one at the other in [(n-Bu)4N+]2[C(NH2)3 +]2(HCO3 –)2[NCC6H4(COO–)]2·2H2O (3); and 1H-imidazole-4,5-dicarboxylate, functioning as a multiple hydrogen-bond acceptor in [(n-Bu)4N+]3[C(NH2)3 +]4(HCO3 –)4[H+{C3N2H–(COO–)(COOH)}2] (4). The resulting planar anionic layer in 1 becomes an undulatory one in 3 and 4. In 2, adjacent wavy layers are supported by centrosymmetric cyclic (GM+)2(H2O)4 “double molecular pillars” to yield a three-dimensional anionic host network.