The reaction heats and PM5 semiempirical studies of complexes formed between silicon podand and monovalent cations

Silicon podands (1-10) were synthesised and their complexation reaction of Na+ cations were studied by calorimetric and PM5 theoretical methods. Both methods provide evidence for formation of the respective complexes with Na+ cations of different stoichiometry. In most cases, only formation of the complexes of 1:1 stoichiometry has been observed. For compounds with longer oxaalkyl chains (9 and 10) the formation of 1:4 and 1:6 complexes has been found. The structures of the complexes are visualised and discussed.