Synthesis, crystal structure and spectroscopic characterization of mono- and tetra-nuclear molybdenum(VI) complexes with 2-mercaptopyridine N-oxide: (n-Bu4N)2[MoO2(PT)2·Mo4O8(μ-O)2(μ3-O)2(PT)2]

(n-Bu4N)4[Mo8O26] reacts with the Na salt of 2-mercaptopyridine N-oxide (NaPT) in MeCN to give the complex (n-Bu4N)2[MoO2(PT)2·Mo4O8(μ-O)2(μ3-O)2(PT)2] (1) which contains two metal centres: one being mononuclear molybdenum chelating to two PT ligands, and the other a tetranuclear oxomolybdenum cluster with two PT ligands at the terminal point. The i.r. spectrum of the title complex exhibits absorption bands at 911.5 and 881.9 cm−1, characteristic of the [cis-MoO2]2+ fragment.