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

The complexation reaction of Li+ cations by silicon podands (1-12) was studied by calorimetric and PM5 semiempirical methods. Both methods provide evidence for formation of the respective complexes with Li+ cations of different stoichiometry. For compounds 1, 2, 4, 6 and 10 only formation of 1:1 complexes were observed whereas for compounds with longer oxaalkyl chains the formation of 1:x (x>1) complexes have been found. The structures of the complexes are visualised and discussed.