for each monomer. From the conformer ensemble, five representative conformers were selected to extract a range of steric and electronic parameters (Figure ). The ensemble conformer properties were condensed to include the lowest energy conformer (low E), minimum (min), maximum (max), and Boltzmann derived parameter value. Additionally, we also extracted condensed properties from the conformer presenting the minimum percent buried volume (Vburmin) parameter value at the active site olefinic carbon (C1), as we hypothesized that steric effects may be a driver of the observed rate differences. Percent buried volume probes the proximal steric environment by placing a 3Å sphere at the site of interest and measuring the resulting overlap. The library of parameters was regressed against ln(kp) to reveal a range of good correlations with various parameters describing steric effects (molar volume (MV), solvent accessible surface area (SASA) and Sterimol B5). These correlations all resulted from the Vburmin conformer values located at the active site olefinic carbon C1. A representative correlation using Sterimol B5 is depicted in Figure . This parameter describes the display of steric information for how the adjacent olefinic carbon C2 may present itself to the propagating Ru chain end (Figure ). The other two strong correlations, MV and SASA, represent the shape of the monomer while accounting for the local environment defined by the Vbur-min conformer.