(AgI)2Te6 and (AgI)2Se6:: New composite materials with cyclic Te6 and Se6 molecules stabilized in the solid solvent AgI

The new deeply colored solids (AgI)(2)Te-6 and (AgI)(2)Se-6 are obtained under hydrothermal conditions in hydroiodic acid. They contain molecules of cyclic hexatellurium and hexaselenium (Te-6, Se-6, respectively, both chair conformations) stabilized in a matrix of AgI. Whereas Se-6 molecules are well known as isolated species in rhombohedral selenium, Te-6 molecules are not known to exist in any modification of that element. They can be stabilized only in an appropriate solid solvent like AgI. To date, the new compound (AgI)(2)Te-6 is the second example only of a composite material containing cyclic Te-6 molecules [the first example is Re6Te10Cl6(Te-6)]. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).