Electron donor for polyolefin polymerization catalysts and uses thereof

1. A polyolefin catalyst comprising an aluminum alkyl, a metal component, and an electron donor of Formula II.a, III.a., III.b., IV.a., or IV.b.:

2. The polyolefin catalyst of claim 1 , wherein the metal component is titanium.

3. The polyolefin catalyst of claim 1 , further comprising a support, wherein the metal component and the electron donor form a catalyst disposed on the support.

4. The polyolefin catalyst of claim 3 , wherein the support comprises a magnesium halide.

5. The polyolefin catalyst of claim 1 , wherein the polyolefin catalyst has an activity of greater than 25 kg/g·hr.

6. The polyolefin catalyst of claim 1 , wherein the polyolefin catalyst has an activity of greater than 30 kg/g·hr.

7. The polyolefin catalyst of claim 1 , wherein the polyolefin catalyst is adapted to produce polypropylene having a polydispersity index (PI) of greater than 3.

8. The polyolefin catalyst of claim 1 , wherein the polyolefin catalyst is adapted to produce polypropylene having a xylene solubles content of less than 8% XS.

9. The polyolefin catalyst of claim 1 , wherein the polyolefin catalyst is adapted to produce polypropylene having a melt flow index of greater than 2 g/10 min.

10. A method for producing polypropylene, the method comprising:

forming a reaction mixture by mixing a silane component with a catalyst, the catalyst component comprising a titanium catalyst, an electron donor, and a magnesium halide; and

adding propylene to the reaction mixture to form a polypropylene batch, wherein a polydispersity index (PI) of the polypropylene batch is greater than 3, wherein a xylene solubles content of the polypropylene batch is less than 8% XS, and wherein a melt flow index of the polypropylene is greater than 2 g/10 min;

wherein the electron donor is of Formula II.a, III.a., III.b., IV.a., or IV.b.: