Potassium-telluroether interactions: structural characterisation and computational analysis

Dissolution of the potassium complex [K(ATe₂^Tripp2)(dme)₂] (1-Te) in THF, layering with hexanes, and cooling to -30 °C afforded X-ray quality crystals of [K(ATe₂^Tripp2)(THF)₃] (2-Te). The K-TeR₂ distances in 2-Te are substantially shorter than those in 1-Te, and DFT and QTAIM calculations support the presence of K-TeR₂ interactions, providing the first unambiguous examples of s-block-telluroether bonding. Attempts to prepare bulk quantities of 2-Te afforded [K(ATe₂^Tripp2)(THF)₂] (3-Te), and further drying yielded [K(ATe₂^Tripp2)(THF)] (4-Te) and [K(ATe₂^Tripp2)] (5-Te). The selenium analogues of 2-Te, 3-Te and 4-Te (2-Se, 3-Se and 4-Se), were also prepared, and 2-Te, 2-Se, 3-Se and 5-Te were crystallographically characterised.