According to the caiculation of quantum chemistry it come be deduced that conngurauons or the catalysts VO(OR)2Cl-Al (i-Bu)3

for the alternating Copolymerization of butadiene with propene

the highest reactive configuration was A. When the catalyst complex forms the configuration A

the energy of the system was the lowest; the central vanadium atom had relatively high positive charge and whose frontier orbital overlapped easily with the frontier orbital of butadiene to form coordination complex

so it was concluded from the experimental results and calculations that the configuration of the catalyst of relatively high actibity was A.