Enhanced anion binding from unusual coordination modes of bis(thiourea) ligands in platinum group metal complexes.

Treatment of a range of bis(thiourea) ligands with inert organometallic transition-metal ions gives a number of novel complexes that exhibit unusual ligand binding modes and significantly enhanced anion binding ability. The ruthenium(II) complex [Ru(η(6)-p-cymene)(κS,S',N-L(3)-H)](+) (2b) possesses juxtaposed four- and seven-membered chelate rings and binds anions as both 1:1 and 2:1 host guest complexes. The pyridyl bis(thiourea) complex [Ru(η(6)-p-cymeme)(κS,S',N(py)-L(4))](2+) (4) binds anions in both 1:1 and 1:2 species, whereas the free ligand is ineffective because of intramolecular NH⋅⋅⋅N hydrogen bonding.

Anion binding inhibition of the formation of a helical organogel.

A chiral tris(urea) organogelator gels dmso-water and methanol-water mixtures at low weight percent. The formation of the helical gel fibres is partially inhibited by addition of chloride, which is bound by the gelator, resulting in fully crystalline material characterised by X-ray crystallography.