Inclusion compounds of thiourea and peralkylated ammonium salts .4. Hydrogen-bonded host lattices built of thiourea and formate ions

New inclusion complexes (C2H5)(4)N+HCO2-.(NH2)(2)CS . H2O (1), [(C2H5)(4)N](2)(+)[(HCO2)(2)H](-)(HCO2-). 2(NH2)(2)CS (2), (n-C3H7)(4)N+HCO2-. 3(NH2)(2)CS . H2O (3) and (n-C4H9)(4)N+[(HCO2)(2)H](-). 2(NH2)(2)CS (4) have been prepared and characterized by X-ray crystallography. Crystal data, MoKalpha radiation: 1, space group P2(1)/c, a = 7.199(2), b = 16.851(2), c = 13.044(2) Angstrom, beta = 100.13(2)degrees, Z = 4, and R-F = 0.065 for 1011 observed data; 2, space group Pca2(1), a = 25.803(5), b = 7.190(2), c = 17.394(2) Angstrom, Z = 4, and R-F = 0.073 for 1515 observed data; 3, space group P2(1)/n, a = 8.533(2), b = 9.423(5), c = 33.517(7) Angstrom, beta = 90.44(2)degrees, Z = 4, and R-F = 0.052 for 2521 observed data; 4, space group Pbca, a = 17.389(3), b = 16.622(2), c = 20.199(3) Angstrom, Z = 8, and R-F = 0.056 for 1910 observed data. In both 1 and 2 the tetraethylammonium ions are sandwiched between puckered layers, which are constructed by the cross-linkage of a parallel arrangement of infinite chains. In I each chain is composed of twisted (thiourea-formate)(2) tetramers bridged by water molecules, whereas in 2 it comprises an alternate arrangement of thiourea dimers and protonated formate trimers each formed by the linkage of a hydrogen diformate ion, [(HCO2)(2)H](-), to a formate ion via a C--H ... O hydrogen bond. In compound 3 two independent thiourea molecules are used to construct a hydrogen-bonded puckered layer normal to the c axis, whereas the remaining thiourea molecule, together with the formate ion and water molecule, generate another puckered layer that is parallel to the first one. Hydrogen bonding between these two types of layers gives rise to a network containing channels running parallel to the [100] direction, and the cations are stacked regularly within each column. In the crystal structure of 4, the thiourea molecules form hydrogen-bonded zigzag ribbons running parallel to the b axis, which are cross-linked by the dimeric formate moieties [(HCO2)(2)H](-) to form a puckered layer and the (n-C4H9)N+ cations occupy the space between adjacent layers.