IN-SITU C-13 NMR-STUDY OF CONJUNCT POLYMERIZATION OF 1-PENTENE IN 95-PERCENT SULFURIC-ACID

C-13 NMR study of ''conjunct polymerisation'' of 1-pentene in 95% sulf uric acid demonstrated that this is a carbenium ion reaction, where th e esters are the precursors of carbenium ions. In the first step of th e reaction a complicated mixture of primary and secondary mono- and di pentyl esters is formed. In an excess of the acid the esters are decom posed yielding aliphatic carbenium ions, which are then involved in se condary reactions resulting in the final products. Similar to heteroge neous catalysis on zeolites, the steady state concentration of the ali phatic carbenium ions during the reaction is, however, too low for the ir direct detection by NMR.