Preparation of iron indium carbonyl complexes [K][In{Fe2(CO)8}2](THF) and Fe2{.mu.-InCl(THF)}2(CO)8 (THF = tetrahydrofuran)

Abstract

The compound [K][In(Fe[sub 2](CO)[sub 8])[sub 2]](THF) (1) (THF = tetrahydrofauran) has been synthesized by the reaction of Fe[sub 3](CO)[sub 12] with activated indium powder in the presence of potassium chloride. A single-crystal X-ray structure determination shows the iron atoms of two Fe[sub 2](CO)[sub 8] units bound to the indium in a pseudotetrahedral fashion and the potassium ion coordinated to a molecule of THF and two carbonyl oxygen atoms from each of four of the iron-indium anions to give a total coordination number of 9. Crystal data: tetragonal space group P4/n (No. 85), a = 11.8502(2) [angstrom], c = 10.696(2) [angstrom], V = 1502.0(5) [angstrom][sup 3], Z = 2, R = 3.61%, R[sub 2] = 5.04%. The complex Fe[sub 2]([mu]-InCl(THF))[sub 2](CO)[sub 8] (2) can be prepared in high yield by the reaction of either Na[sub 2]Fe(CO)[sub 4] or Na[sub 2]Fe[sub 2](CO)[sub 8] with indium(III) chloride or via the reaction of Fe[sub 3](CO)[sub 12] with indium(I) chloride in tetrahydrofuran. Mechanistic studies suggest that these three reactions produce the same intermediate species, Fe(CO)[sub 4](THF) and InCl, which then combine to give the observed product. Fe[sub 2]([mu]-InCl(THF))[sub 2](CO)[sub 8] forms an adduct with bromide ion in the presence of tetrabutylammonium bromide, and the complexmore » [(C[sub 4]H[sub 9])[sub 4]N][sub 2][Fe[sub 2]([mu]-InClBr)[sub 2](CO)[sub 8]] (3) has been characterized crystallographically. Crystal data: triclinic space group PI (No. 2), a = 11.510(2) [angstrom], b = 11.905(1) [angstrom], c = 12.200(2) [angstrom], [alpha] = 90.373(9)[degrees], [gamma] = 107.75(1)[degrees], V = 1396.6(5) [angstrom][sup 3], Z = 1, R = 4.61%, R[sub 2] = 5.94%.« less