| abstract |
FIELD: chemistry. n SUBSTANCE: invention relates to a method of maintaining stable catalytic activity during tetramerisation of ethylene and a method of producing 1-octene via tetramerisation of ethylene. Tetramerisation is carried out in the presence of a catalyst system containing chromium or a chromium precursor, alkylaluminoxane and a ligand with the backbone structure P-C-C-P, of formula 1, where R 1 , R 2 , R 3 and R 4 each independently denotes phenyl or substituted phenyl and R 1 , R 2 , R 3 and R 4 each does not have substitutes on atoms neighbouring atoms bonded with P atoms, and R 5 , R 6 denote a methyl group. n EFFECT: disclosed methods enable stable sustenance of catalytic activity compared to ordinary catalyst systems. n 2 cl, 2 dwg, 2 tbl, 17 ex |