A new Pr-i(2)-tacn(-)-supported alkyl tantalum species, (Me3SiCH2)(2)(RN=)T
a(mu -CH2SiMe3)(mu -n(1):n(3)-(i)-Pr-2-tacn)Li (R = 2,6-(Pr2C6H3)-Pr-i; 2),
was synthesized and found to undergo alpha -H abstraction under gentle hea
ting to form the alkylidene (Me3SiCH2)(RN=)Ta(mu -CHSiMe3)(mu -n(1):n(3)-Pr
-i(2)-tacn)Li (3), The syntheses and crystal structures of 2 and 3 and thei
r precursor ((Pr-i(2)-tacn)TaCl2(=NR) (1)) are described, as well as kineti
c data for the first-order thermolysis reaction producing 3.