Thorough kinetic characterization of single-site olefin polymerization catalysis requires comprehensive, quantitative kinetic modeling of a rich multiresponse data set that includes monomer consumption, molecular weight distributions (MWDs), end group analysis, etc. at various conditions. Herein we report the results obtained via a comprehensive, quantitative kinetic modeling of all chemical species in the batch polymerization of 1-hexene by rac-C(2)H(4)(1-Ind)(2)ZrMe(2) activated with B(C(6)F(5))(3). While extensive studies have been published on this catalyst system, the previously acknowledged kinetic mechanism is unable to predict the MWD. We now show it is possible to predict the entire multiresponse data set (including the MWDs) using a kinetic model featuring a catalytic event that renders 43% of the catalyst inactive for the duration of the polymerization. This finding has significant implications regarding the behavior of the catalyst and the polymer produced and is potentially relevant to other single-site polymerization catalysts, where it would have been undetected as a result of incomplete kinetic modeling. In addition, comprehensive kinetic modeling of multiresponse data yields robust values of rate constants (uncertainties of less than 16% for this catalyst) for future use in developing predictive structure-activity relationships.

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A series of single-site catalysts with mixed cyclopentadienyl/aryloxide ligation were synthesized and used to polymerize 1-hexene. The effects of solvent, metal, counterion, and ligand structure were investigated by experiments and by DFT calculations. A solvent with a high dielectric constant led not only to an increase in the chain propagation rate but also to a change in the reaction order. Catalyst reactivity was found to be controlled by the difficulty of ion pair separation and steric congestion at the metal center, which were quantified from DFT simulation by SCF ion pair separation energies and ligand cone angles. A Cp*Ti(OC 6 H 4 -2-Br)Me 2 /B(C 6 F 5 ) 3 catalyst exhibits unusually high reactivity, which was correlated to the formation of a partial bond between the aryloxide ortho substituent bromide and Ti upon ion pair separation. Natural bond orbital analysis was used to quantify the order of this opportunistic ligation for a series of catalysts. Kinetic analysis and a structure-activity correlation were applied to interpret the experimental results.

Well designed domain specific languages have three important benefits:(1) the easy expression of problems, (2) the application of domain specific optimizations (including parallelization), and (3) dramatic improvements in productivity for their users. In this paper we describe a compiler and parallel runtime system for modeling the complex kinetics of rubber vulcanization and olefin polymerization that achieves all of these goals. The compiler allows the development of a system of ordinary differential equations describing a complex vulcanization reaction or single-site olefin polymerization reaction-a task that used to require months-to be done in hours. A specialized common sub-expression elimination and other algebraic optimizations sufficiently simplify the complex machine generated code to allow it to be compiled-eliminating all but 8.0% of the operations in our largest program and enabling over 60 times faster execution on our largest benchmark codes. The parallel runtime and dynamic load balancing scheme enables fast simulations of the model.

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