Structures of chlorohydroxobis(pentamethylcyclopentadienyl)tantalum(V) trifluoromethanesulfonate (triflate) and dihydroxobis(pentamethylcyclopentadienyl)tantalum(V) triflate

[Ta(C_(10)H_(15))2(C1)(OH)][CF_3SO_3] (I), Mr = 652.94, monoclinic, P2_1/n, a = 9.965(7), b = 18.796 (5), c = 13.269 (3)Å, β = 94.02 (3)°, V = 2479-2 (19)Å^3, Z = 4, D_x = 1.75 g cm^(-3), λ(Mo Kce) = 0.71073 Å, µ = 46 cm^(-1), F(000) = 1288, room temperature, R = 0.107 for 3702 reflections with F_o^2 > 0 [R=0.053 for 2094 reflections with F_o^2 > 3σ(F_o^2)]. [Ta(C_(10)H_(15))_2(OH)_2][CF_3SO_3] (II), M_r = 634.49, triclinic, P1, a = 10⋅052 (2), b = 10⋅111 (2), c = 12⋅739(2) Å, ɑ = 71⋅38(2), β = 78⋅21 (1), y = 77⋅40 (2)°, V = 1184⋅7 (4)Å^3, Z = 2, D_x = 1⋅78 g cm^(-3), λ(Mo Kɑ) = 0⋅71073 Å, µ = 47 cm^(-1) F(000) = 628, room temperature, R = 0⋅032 for 4046 reflections with Fo g > 0 [R = 0⋅026 for 3664 reflections with F_o^2 > 3σ(F_o^2)]. Severe disorder of the triflate anion in (I) led to a less satisfactory structure, but cations in both compounds are well defined, with normal Ta─Cp^* geometry. Ta─C1 2⋅343 (4), Ta─O 1⋅853 (8)Å and C1─Ta─O 96⋅4 (3)° in (I); Ta─O 1⋅907(6)A and O─Ta─O 100⋅4(2)° in (II). Tantalum-bound OH groups are hydrogen bonded to triflate O atoms