Synthesis, structure, and redox properties of the sulfido bridged tetranuclear cluster complex [(Ph 3P) 2N][Fe 3(CO) 9{μ 3-SFeCp(CO) 2}

Abstract

Reaction of [CpFe(CO) 2THF]BF 4 with [(Ph 3P) 2N] 2[Fe 3(CO) 9(μ 3-S)] ( 1) produces the new cluster [(Ph 3P) 2N][Fe 3(CO) 9{μ 3-SFeCp(CO) 2}] ( 2), which consists of a Fe 3(CO) 9S fragment coordinated to the iron atom of CpFe(CO) 2. Compound 2 was characterized by 1H and 13C NMR, mass spectroscopy, elemental analysis, cyclic voltammetry, and single crystal X-ray structure determination. Compound 2 undergoes a quasi reversible oxidation at 0.19 V versus Ag ∣ AgCl. Chemical oxidation of 2 by tropylium produces the known cluster Fe 3(CO) 9(μ 3-S) 2. Thermolysis of 2 yields the known compounds [CpFe(CO) 2] 2, [(Ph 3P) 2N] 2[Fe 3(CO) 9(μ 3-S)], and [(Ph 3P) 2N] 2[Fe 5(CO) 14(μ 3-S) 2] ( 3), which were identified by IR and mass spectrometry.