Synthesis and Characterization of the Novel Iron Carbonyl Tellurium Chloride Cluster [Fe_2(CO)_6(mu-Cl(mu-TeCl)_2]_2[eta~2,mu _2,mu_2-Te_2Cl_(10)], and Its Decomposition to the Zintl Ion Complex [Fe_2(CO)_6(eta~2, mu_2,mu_2-Te_4)(mu-TeCl_2)]

摘要

Clusters comprising transition metal carbonyls and phos-phanes with heavy chalcogenide main group elements have been studied in several groups, particularly in the last decade. This work has shown these types of compounds to have a very rich and varied chemistry, and compounds of new structural types continue to be produced. The types of compounds observed have ranged from simple complexes and small clusters through polynuclear clusters with large cage structures. In addition, some very novel complexes of polychalcogemde (Zintl) ions with transition metals have been produced in recent years. However, such compounds containing intact chalcogenide - halogen bonds have been conspicuously absent, with the exception of one recent report. In an attempt tooxidize the square-pyramidal cluster [Te_2Fe_3(CO)_9] to a cationic species which would be isoeiectronic to the known Group 15 compound [Bi_2Fe_3(CO)_9], we studied its reactivity toward SO_2Cl_2 and SOC1_2, which are known to oxidize main group centers. Rather than oxidation to [Te_2Fe_3(CO)_9]~(2+), we observed a complex halogenation reaction that gave some very interesting new compounds. Here we report the synthesis and structural characterization of the iron carbonyl tellurium chloride cluster 1. and its decomposition to the complex 2, which contains both a novel dibridging Te_4 unit and a linear TeCl_2 moiety.