The preparation and properties of MʹM5X8 (X = Se, Te; M = Cr, Ti; Mʹ = Li, Na, K, Rb, Cs, Cd, Sn, Pb) via low temperature ion exchange reaction

Low temperature ion exchange reactions were used to prepare an isostructural series of compounds, MʹM5X8 (X = Se, Te; M = Cr, Ti; Mʹ = Li, Na, K, Rb, Cs, Cd, Sn, Pb) in which the exchanged cations reside in one-dimensional tunnels within the structure. Calorimetry and diffraction measurements were used to follow the exchange process and chemical analysis of the products showed a dependence on the extent of exchange with cation size. Exchange of divalent cations into the Cr5X8 framework led to a doubling of the unit cell in the tunnel direction due to an ordering of the cations while divalent cations in the Ti5Se8 framework remained randomly ordered. Magnetic susceptibility studies on several of the products indicated only small perturbations on the magnetic properties of the parent compounds as a result of cation exchange.