[en] The crystal and molecular structures of the trinuclear molecular cluster Fe₃(μ₃-O)(CF₃COO)₆](C₆H₅)₃PO]₃ have been determined: α = 22.045(10), b = 26.390(11), c = 14.265(9) A, γ = 61.90(2)⁰, Z = 4, space group P2₁/b (diffractometer, λCu Kα, 2939 reflections, R = 0.074). The iron atoms are located at the corners of an almost equilateral triangle with sides measuring 3.325-3.374 A. The central bridging O(4) oxygen atom joins all three iron atoms, which are joined further in pairs by six bridging CF₃COO groups acting as bidentate ligands. The coordination of each iron atom is completed to octahedral by the triphenylphosphine oxide ligands. Gamma-resonance spectroscopy in the 80-300⁰K temperature range has revealed a change in the character of the spectra at a temperature >210⁰K, which is interpreted as the temperature for delocalization of an electron over a system of three centers corresponding to a gamma-resonance time scale of ∼ 10^-7 sec. At 300⁰K the gamma-resonance spectra describe three different states for the iron atoms, in agreement with the x-ray data