Synthesis and Crystal Structure of Tetrabutylammoniumtetrachloroferrate(III)

Abstract

Tetrabutylammoniumtetrachloroferrate(III) compound, [n-Bu₄N]⁺[FeCl₄]⁻ has been prepared and characterized by elemental analysis and X-ray studies. It crystallizes in the orthorhombic system, space group Pnna, with Mr = 220.05 (C8H₁₈N_0.5Cl₂Fe_0.5), a = 18.510(4) Å, b = 11.553(2) Å, c = 11.442(2) Å, V = 2446.8(8) ų, Z = 8, D_c = 1.195 g/cm³, F(000) = 932, μ = 1.051 mm^-1, the final R = 0.0825, wR = 0.0860 and S = 1.101. The total reflections were 4727 and the independent ones were 2196 (R_int = 0.0697), of which 827 were observed with I > 2σ(I). The crystal structure consists of one independent [FeCl₄]⁻ anion and one independent [n-Bu₄N]⁺ cation. In the [FeCl₄]⁻ anion, the central Fe atom adopts distorted tetrahedral geometry with the four Cl atoms, and the Fe-Cl distances are 2.122(14) and 2.1807(17) Å, respectively. In the [n-Bu₄N]⁺ cation, the N atom adopts a slightly distorted tetrahedral geometry. In the solid state, the hydrogen bondings link [FeCl₄]⁻ anion and [n-Bu₄N]⁺ cation which stabilize the structure.