The present invention relates to compositions and processes of making ethylene/α-olefins. More particularly, the invention relates to processes of producing ethylene/α-olefin compositions having a controlled molecular weight distribution. The molecular weight distribution is controlled, for example, by controlling the relative monomer concentrations during contact with a pre-catalyst and/or using a catalyst comprising a catalytic amount of a molecule having the structure: wherein M=group 2-8 metal, preferably group 4 as a neutral or charged moiety; Y=any substituent including fused rings; L=any ligating group, especially a pyridyl or pyridylamide; X=alkyl, aryl, substituted alkyl, H or hydride, halide, or other anionic moiety; y=an integer from 0 to the complete valence of M; R=alkyl, aryl, haloalkyl, haloaryl, hydrogen, etc; x=1-6, especially 2; Dashed line=optional bond, especially a weak bond; and X and (CR2)x may be tethered or part of a ring.