Metallocene compounds and method for synthesis of monocyclopentadienyl, monoindenyl, and monofluorenyl metallocene compounds

A method of synthesizing a metallocene compound, the method comprising:

• reacting a first mixture comprising a bis-Cp metallocene compound represented by formula (I), a metal salt, and a solvent to form a reaction product mixture comprising a liquid component and a solid component, the bis-Cp metallocene compound represented by formula (I) is:
• wherein:
• M of formula (I) is a Group 4 metal;
• CpA of formula (I) is an unsubstituted cyclopentadienyl group, a substituted cyclopentadienyl group, an unsubstituted indenyl group, a substituted indenyl group, an unsubstituted fluorenyl group, or a substituted fluorenyl group;
• and
• each X of formula (I) is, independently, H (hydride), a halogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, or a functional group comprising at least one element from Group 13-16 of the periodic table of the elements;
• separating the liquid component of the reaction product mixture from the solid component of the reaction product mixture;
• and
• reacting a second mixture comprising the liquid component of the reaction product mixture and a donor molecule to form a mono-Cp metallocene compound represented by formula (II):
• wherein:
• M of formula (II) is the Group 4 metal;
• CpA of formula (II) is the unsubstituted cyclopentadienyl group, the substituted cyclopentadienyl group, the unsubstituted indenyl group, the substituted indenyl group, the unsubstituted fluorenyl group, or the substituted fluorenyl group;
• each X of formula (II) is, independently, H (hydride), a halogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, or a functional group comprising at least one element from Group 13-16 of the periodic table of the elements;
• D of formula (II) is, independently, a monodentate donor ligand or a bidentate donor ligand;
• D and X of formula (II) are different;
• and
• n of formula (II) is a number greater than 0.

A method of synthesizing an unbridged asymmetric metallocene compound, the method comprising:

• reacting a first mixture comprising a bis-Cp metallocene compound represented by formula (I), a metal salt, and a solvent to form a reaction product mixture comprising a liquid component and an optional solid component, the bis-Cp metallocene compound represented by formula (I) is:
• wherein:
• M of formula (I) is a Group 4 metal;
• CpA of formula (I) is an unsubstituted cyclopentadienyl group, a substituted cyclopentadienyl group, an unsubstituted indenyl group, a substituted indenyl group, an unsubstituted fluorenyl group, or a substituted fluorenyl group;
• and
• each X of formula (I) is, independently, H (hydride), a halogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, or a functional group comprising at least one element from Group 13-16 of the periodic table of the elements;
• reacting a second mixture comprising the liquid component of the reaction product mixture and a donor molecule to form a mono-Cp metallocene compound represented by formula (II):
• wherein:
• M of formula (II) is the Group 4 metal;
• CpA of formula (II) is the unsubstituted cyclopentadienyl group, the substituted cyclopentadienyl group, the unsubstituted indenyl group, the substituted indenyl group, the unsubstituted fluorenyl group, or the substituted fluorenyl group;
• each X of formula (II) is, independently, H (hydride), a halogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, or a functional group comprising at least one element from Group 13-16 of the periodic table of the elements;
• D of formula (II) is, independently, a monodentate donor ligand or a bidentate donor ligand;
• D and X of formula (II) are different;
• and
• n of formula (II) is a number greater than 0;
• and
• contacting the mono-Cp metallocene compound represented by formula (II) with a complex of a CpB ligand to form an unbridged asymmetric metallocene compound represented by formula (VII):
• wherein:
• M of formula (VII) is the Group 4 metal;
• CpA of formula (VII) is the unsubstituted cyclopentadienyl group, the substituted cyclopentadienyl group, the unsubstituted indenyl group, the substituted indenyl group, the unsubstituted fluorenyl group, or the substituted fluorenyl group;
• CpB of formula (VII) is an unsubstituted cyclopentadienyl group, a substituted cyclopentadienyl group, an unsubstituted indenyl group, a substituted indenyl group, an unsubstituted fluorenyl group, or a substituted fluorenyl group;
• CpA and CpB of formula (VII) are different;
• each X of formula (VII) is, independently H, a halogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, or a functional group comprising at least one element from Group 13-16 of the periodic table of the elements;
• and
• each X of formula (VII) is different from D of formula (II).