CATALYST COMPONENT

This invention relates to components useful in propylene polymerization catalysts, and in particular provides a solid, hydrocarbon-insoluble, catalyst component containing magnesium, titanium, and halogen and further comprising a modifier compound with a structure (1) wherein R1 and R'1 are each independently selected from alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms, R2 to R5 and R'2 to R'5 are each independently selected from H and alkyl groups having 1 to 6 carbon atoms, R6 and R'6 are each independently selected from H and alkyl groups having 1 to 4 carbon atoms, and the alkyl groups optionally comprising one or more heteroatoms.