Application of the hydro(solvento)thermal technique to the synthesis of metal carbonyl chalcogenide clusters. 2. Synthesis and x-ray structures of [[Fe4Te4(CO)10]2(Te2)]2- and [[Fe2Se(CO)6]2(Se2)]2-

Abstract

The hydrothermal reaction of Fe(CO)[sub 5] with Na[sub 2]Te[sub 2] in the presence of Ph[sub 4]PCl at 110[degrees]C forms (Ph[sub 4]P)[sub 2][[l brace]Fe[sub 4]Te[sub 4](CO)[sub 10][r brace][sub 2](Te[sub 2])] (I) while the reaction of Fe(CO)[sub 5] with Na[sub 2]Se[sub 2] in superheated methanol at 80[degrees]C results in (Ph[sub 4]P)[sub 2][[l brace]Fe[sub 2]Se(CO)[sub 6][r brace][sub 2](Se[sub 2])] (II). The structures of (I) and (II) were determined by X-ray single-crystal analysis. (I) crystallizes in the space group P[bar 1], and (II) in the space group P2[sub 1]/n. The [[l brace]Fe[sub 4]Te[sub 4](CO)[sub 10][r brace][sub 2](Te[sub 2])][sup 2[minus]] anion in (I) forms a ditelluride, Te[sub 2][sup 2[minus]], bridged double cubane-like structure with eight iron atoms in two Fe[sub 4]Te[sub 4] cubes being octahedrally-coordinated by briding tellurium ligands and terminal CO groups. The [[l brace]Fe[sub 2]Se(CO)[sub 6][r brace][sub 2](Se[sub 2])][sup 2[minus]] molecule in (II) adopts a double butterfly' conformation caused by an intramolecular Se-Se linkage between two Fe[sub 2]Se[sub 2](CO)[sub 6] units. All iron atoms in this structure have a distorted octahedral geometry achieved by selenium ligands, CO groups, and a Fe-Fe single bond. The average Fe-Te bond distance is 2.619(4) [Angstrom], and Fe-Se = 2.386(17) [Angstrom]. 30 refs., 4 figs., 5 tabs.