PREPARATION OF [K][IN(FE2(CO)8)2](THF) AND FE2(MU-INCL(THF))2(CO)8 (THF = TETRAHYDROFURAN)

The compound [K][In{Fe2(CO)8}2] (THF) (1) (THF = tetrahydrofuran) has been synthesized by the reaction of Fe3(CO)12 with activated indium po wder in the presence of potassium chloride. A single-crystal X-ray str ucture determination shows the iron atoms of two Fe2(CO)g units bound to the indium in a pseudotetrahedral fashion and the potassium ion coo rdinated 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 = 11.850(2 ) angstrom, c = 10.696(2) angstrom, V = 1502.0(5) angstrom3, Z = 2, R = 3.61%, R(w) = 5.04%. The complex Fe2{mu-InCI(THF)12(CO)8 (2) can be prepared in high yield by the reaction of either Na2Fe(CO)4 or Na2Fe2( CO)8 with indium(III) chloride or via the reaction of Fe3(CO)12 with i ndium(I) chloride in tetrahydrofuran. Mechanistic studies suggest that these three reactions produce the same intermediate species, Fe(CO)4( THF) and InCl, which then combine to give the observed product. Fe2{mu -InCl(THF)12(CO)8 forms an adduct with bromide ion in the presence of tetrabutylammonium bromide, and the complex [(C4H9)4N]2[Fe2{mu-InClBr} 2(CO)8] (3) has been characterized crystallographically. Crystal data: triclinic space group P1BAR (No. 2), a = 11.510(2) angstrom, b = 11.9 05(1) angstrom, c = 12.200(2) angstrom, a = 90.373(9)-degrees, beta = 117.08(1)-degrees, gamma = 107.75(1)-degrees, V = 1396.6(5) angstrom3, Z = 1, R = 4.61%, R(w) = 5.94%.