Crown compounds for anions. A polymeric complex of cyclic trimeric perfluoro- o-phenylenemercury with thiocyanate anion containing an infinite helical chain of alternating molecules of mercury-containing macrocycle and SCN − ions

Abstract

It has been shown by IR spectroscopy that cyclic trimeric perfluoro- o-phenylenemercury ( o-C 6F 4Hg) 3 is capable of binding thiocyanate anions in acetone solution, forming complexes whose composition is dependent on the ratio of reagents. In the interaction of ( o-C 6F 4Hg) 3 with an equimolar amount of [ nBu 4N] + SCN − in ethanol the complex formulated as [(o- C 6 F 4 Hg) 3( SCN)] −[ n Bu 4 N] + has been isolated. An X-ray diffraction study of the complex has revealed that in the solid state it is polymeric and contains an infinite helical chain of alternating ( o-C 6F 4Hg) 3 molecules and thiocyanate anions. Every SCN − ion in the complex is bonded to the mercury atoms of two neighbouring molecules of the macrocycle through the sulphur atom and forms with each of these molecules two relatively short Hg … S bonds and one considerably longer Hg … S bond.