The influence of π-bonding and steric factors on helahalogeno-metallates

Abstract

A comparison of the asymmetric stretching frequency v₃ and unit cell length a₀ for a series of hexahalogeno-metallates A₂MX₆ [A = K⁺, Rb⁺, Cs⁺ and NH₄⁺, M = Ru, Os, Sn and Te and X = Cl,Br] has been made. Trends observed for the tellurium and tin compounds may be related to stericfactors whereas possible M → X d_π-p_π bonding may explain the opposite trend found for ruthenium and osmium compounds.