Oligomerization and Oxide Formation in Bismuth Aryloxides:  Synthesis, Characterization, and Structures of [NaBi(OC₆F₅)₄(THF)]_∞and Na₄Bi₂(μ₆-O)(OC₆F₅)₈(THF)₄

Abstract

The reaction of [Bi(OR(f))(3).C(7)H(8)](2) (R(f) = C(6)F(5)) with sodium pentafluorophenolate leads to two new mixed-metal aryloxide complexes depending upon stoichiometry. Using 1 equiv of NaOR(f) per bismuth atom, a polymeric chain with the formula [NaBi(OC(6)F(5))(4)(THF)](infinity), 1, was isolated. If 2 equiv of NaOR(f) is used, the heterometallic oxo/aryloxide Na(4)Bi(2)(&mgr;(6)-O)(OC(6)F(5))(8)(THF)(4), 2, is formed. The mass spectroscopic data confirms the elimination of the bis(pentafluorophenyl) ether, R(f)OR(f), concomitant with oxo-ligand formation. The compounds have been characterized spectroscopically and by single-crystal X-ray diffraction: Compound 1 crystallizes in the chiral monoclinic space group P2(1), with a= 12.324(2) Å, b = 10.934(2) Å, c = 13.334(3) Å, beta = 91.19(3) degrees, V = 1796.4(6) Å(3), and Z = 2. The polymeric chain in 1 sits about the 2-fold screw axis and is the source of chirality for the compound. Compound 2 crystallizes in the triclinic space group P&onemacr;, with a = 14.059(3) Å, b = 14.060(3) Å, c = 11.531(2) Å, alpha = 108.47(3) degrees, beta = 102.78(3) degrees, gamma = 108.61(3) degrees, V=1912.6(7) Å(3), and Z = 1 and shows occupational disorder of the sodium and bismuth atom positions. Variable-temperature (19)F-NMR studies show dynamic behavior of these bismuth aryloxide complexes in solution.