A Mössbauer study of xenon compounds

A large number of xenon compounds have been synthesized and studied by nuclear gamma resonance of the 39.6 keV transition in 129Xe. The quadrupole interaction strengths (Q.S.) of all divalent xenon compounds with linear F–Xe–F groups lie close together, but a small increase of the Q.S. with the acceptor strength of adduct groups is observed. For compounds with F–Xe–O– and –O–Xe–O– groups a reduction of the Q.S. of up to 10% is found. The tetravalent compounds exhibit a Q.S. with absolute magnitude very close to that of the divalent compounds, consistent with a square planar configuration and nearly equal contributions to the Q. S. for each Xe–F bond. Hexavalent xenon in XeF6 also exhibits an appreciable Q.S., indicative of distortion of the octahedral fluorine configuration around the xenon atom in the polymeric solid. An increase of the Q.S. relative to XeF6 is observed in the adducts and in hexavalent compounds with mixed oxygen/fluorine bonding. This is interpreted as due to increased distortion around the central xenon atom.