Is there a transition state for the insertion

Is there a transition state for the insertion of ethylene into the Ziegler-Natta catalyst? Amit Aravapalli Gary Kapral

Transition State

Density Functional Theory n n n The idea of expressing the total energy of a system as a functional of the total electron density. In contrast to Hartree Fock method, DFT starts with a consideration of the entire electron system. Total energy is decomposed into three contributions: Kinetic Energy, Coulomb Energy, and Exchange Correlation Energy.

Density Functional Theory vs. Hartree-Fock n n n Both provide structural, energetic, and vibrational properties. EHF=Enuclear+Ecore+Ecoulomb+Eexchange EDFT=Enuclear+Ecore+Ecoulomb+[Eexchange(P)+ Ecorrelation(P)] E=f(x, y, z, m) E=f(f(x, y, z, m))

Density Functional Theory vs. Hartree-Fock n n n DFT is better because: DFT enables the prediction of electronic, optical, and magnetic properties of condensed phases. DFT takes electron correlation into account. DFT can be used in many different ways which leads to efficient methods for particular materials. DFT performs better than HF at lower costs.

Ziegler-Natta Polymerization n What is it? n n n Vinyl polymerization Transition metal catalyst How was it discovered? n n Discovered by Karl Ziegler Developed by Giulio Natta n What do they do? n n High polymerization Can be syndiotactic or isotactic

A look at the catalyst. . . Mac. Spartan Pro

Animation of Sample Rxn ZN Link

Our Transition State Our Discovery

n Special Thanks to Bob Gotwals and Dr. Halpin for making this course possible.