The title compound, (C24H20P)2[CoCl4], was prepared under hydro-thermal conditions. In the crystal, the tetra-phenyl-phospho-nium cations are linked by pairs of weak C-H⋯π inter-actions into supra-molecular dimers; the Co(II) cations lie on twofold rotation axes and the tetra-hedral [CoCl4](2-) anions are linked with the tetra-phenyl-phospho-nium cations via weak C-H⋯Cl hydrogen bonds.

In the structure of the title salt, (C5H14N3)2[CuCl4], the Cu(II) atom in the anion lies on a twofold rotation axis. The tetra-chlorido-cuprate(II) anion adopts a flattened tetra-hedral coordination environment and inter-acts electrostatically with the tetra-methyl-guanidinium cation. The crystal packing is additionally consolidated through N-H⋯Cl and C-H⋯Cl hydrogen bonds, resulting in a three...

Mono- and tetra-deprotonated 2-methylresorcinarene anions ( and ) as their trans-1,4-diammoniumcyclohexane inclusion complexes are reported. The mono-anion forms a fully closed dimeric capsule [·H2O·MeOH]2(2-) with a cavity volume of 165 Å(3) and as the guest with an extremely high packing coefficient, PC = 84.2%, while the tetra-anion forms a close-packed structure with two structurally isomer...

The title compound, C(4)H(12)N(+)·C(8)H(11)NO(5)PS(-), was obtained from tetra-methyl-ammonium hydroxide and dimeth-yl(phenyl-sulfon-yl)amido-phosphate. The tetra-methyl-ammonium cation has a slightly distorted tetra-hedral configuration and the N-C bond lengths lie in the range 1.457 (3)-1.492 (3) Å. In the crystal, no classical hydrogen bonds are observed between the cation and the anion.

In the title salt, C(19)H(15)N(4) (+)·C(24)H(20)B(-), the tetra-phenyl-borate anion is in a tetra-hedral geometry around the B atom [C-B-C angles of 107.10 (9)-111.79 (9)°]. In the cation, the tetra-zole ring makes dihedral angles of 3.04 (7), 51.75 (7) and 51.13 (7)° with the attached phenyl rings. In the crystal, C-H⋯π inter-actions link the cations and anions into ion pairs.

Selective detection of Sm 3+ ion at a very low concentration is achieved using tetra-coordinated boron appended Zinc(salen).