Patent ID: 7858816

Claim:
A method for making a tantalum compound of Formula I: wherein: R 1 , R 2 , R 3 and R 4 can be the same as or different from one another, and each is independently selected from the group consisting of hydrogen, hydrocarbyl, alkyl, silyl, alkylamino, alkenyl, aryl and hydrazyl, with the provisos that R 1 =R 2 ≠iso-propyl, and R 1 =R 2 ≠cyclohexyl; wherein said R 1 , R 2 , R 3 and R 4 may be optionally further substituted with a N, S, O, or a halogen atom, said method comprising the step of: (a) reacting a compound of Formula II below: M(NR 3 R 4 ) 5 (Formula II), with a compound of Formula III: R 1 N═C═NR 2 (Formula III), wherein M is tantalum and R 1 , R 2 , R 3 and R 4 are as indicated above.