Alkyne polymerization on the titanosilicate molecular sieve ETS-10

An IR and UV-VIS study of the interaction of methyl and ethyl acetylene with the acidic form of zeolite ETS-10 is here presented. It is shown that, in the first adsorption step (at room temperature) pi hydrogen-bonded adducts are formed between the alkyl acetylene and the zeolite hydroxy groups. These hydrogen bonded species act as precursors in the second step, where oligomerization takes place, leading to formation of carbocationic double bond conjugated systems of increasing length.