Calculations have been carried out on the complexation energy of acrylonitrile and ethylene using derivatives of the cationic (NN)-N-boolean AND Ni(II)-diimine Brookhart complex. For acrylonitrile (CH2=CHCN) considerations were given to both T binding through the olefinic C=C functionality and a binding through the NC group. The diimine ring system (NN)-N-boolean AND = -NR''CR1-CR2NR'' with R'' = 2,6-C6H3(i-Pr)(2) and R-1, R-2 = CH3 was functionalized by substituting a carbon in the diimine ring by B- and R-1 or R-2 (or both) by anionic groups (BF3-, OBF3-, etc.). Substitutions were also carried out at the aryl rings by replacing H or i-Pr with anionic groups. The objective has been to find substitutions that would reduce or eliminate the preference for a complexation of acrylonitrile, a prerequisite for ethylene/acrylonitrile copolymerization.