BIS(ARENE)VANADIUM COMPLEXES - A STRUCTURAL STUDY

Bis(eta-6-mesitylene)vanadium(0), (1): [V(C9H12)2], M(r) = 291.3, orthorhombic, Ccca, a = 19.529 (1), b = 29.559 (2), c = 16.446 (4) angstrom, V = 9493 (3) angstrom 3, Z = 24, D(x) = 1.23 g cm-3, graphite-monochromated Mo K-alpha-radiation, lambda = 0.71069 angstrom, mu = 5.64 cm-1, F(000) = 3720, T = 293 K, R = 0.058 for 1522 independent reflections. Potassium bis-(eta-6-mesitylene)vanadate dioxane/tetrahydrofuran (0.5/1) solvate, (2): K[V(C9H12)2].C4H8O.1/2C4H8O2, monoclinic, P2(1)/n (the space group assignment was not unambiguous), a = 10.213 (2), b = 18.518 (3), c = 13.402 (3) angstrom, beta = 89.58 (1)-degrees, V = 2535 (1) angstrom 3, Z = 4, D(x) = 1.17 g cm-3, Mo K-alpha-radiation, lambda = 0.71069 angstrom, mu = 5.56 cm-1, F(000) = 952, T = 293 K, R = 0.073 for 1211 independent reflections. The asymmetric unit of (1) contains one eclipsed sandwich molecule in a general position and half a molecule lying around a crystallographic C2 axis. The ionic species (2) retains the sandwich structure and establishes contact ion pairs with the K+ cations, which also interact with tetrahydrofuran and dioxane solvent molecules in a complex packing pattern.