Synthesis of [Mo₃S₄] Clusters from Half-Sandwich Molybdenum(V) Chlorides and Their Application as Platforms for [Mo₃S₄Fe] Cubes

Abstract

Triangular [Mo3S4] clusters are known to serve as platforms to accommodate a metal atom M, furnishing cubic [Mo3S4M] clusters. In this study, three [Mo3S4] clusters supported by η5-cyclopentadienyl (CpR) ligands, [CpR 3Mo3S4]+ (CpR = C5Me4SiMe3, C5Me4SiEt3, and C5Me4H), were synthesized via half-sandwich molybdenum chlorides CpRMoCl4. In the cyclic voltammogram of the [Mo3S4] cluster having C5Me4H ligands, a weak feature appeared in addition to the [CpR 3Mo3S4]0/– redox process, indicating the interaction between [CpR 3Mo3S4]− and the [NnBu4] cation of the electrolyte, while such a feature was less significant for the C5Me4SiR3 variants. The [Mo3S4] clusters with bulky C5Me4SiR3 ligands were successfully applied as platforms to accommodate an Fe atom to furnish cubic [Mo3S4Fe] clusters. On the other hand, the corresponding reactions of the less bulky C5Me4H analogue gave complex mixtures.

Hydrolysis of Element (White) Phosphorus under the Action of Heterometallic Cubane-Type Cluster {Mo3PdS4}

“…These signals correspond to the formation of [Mo 3 {PdP(OH) 3 }S 4 Cl 3 (dbbpy) 3 ] + (Figure 1), in which the Pd atoms bears the tautomeric form of phosphorous acid H 3 PO 3 (P(OH) 3 ) formed by the hydrolysis of white phosphorus. These results nicely fit with the previously published data [28,29], where the signals around 115 ppm in 31 with PCl 3 or H 3 PO 3 in 4M HCl. The total conversion of white phosphorus (by 31 P NMR spectroscopy) in these reactions was 96.7% for complex 1 and 68.0% for complex 2.…”

“…These results nicely fit with the previously published data [28,29], where the signals around 115 ppm in 31 P NMR spectra were attributed to the complexes [Mo3{PdP(OH)3}S4(H2O)9-xClx] (4-x)+ obtained by the reaction of [Mo3{PdCl}S4(H2O)9] 3+ with PCl3 or H3PO3 in 4M HCl. The total conversion of white phosphorus (by 31 P NMR spectroscopy) in these reactions was 96.7% for complex 1 and 68.0% for complex 2. In order to boost the activity of clusters 1 and 2, we attempted modification of their ligand surrounding by the substitution of the chloride-ions from the first and the second coordination spheres with weakly coordinated ions, and in this way to increase the electrophilic properties of Pd.…”

“…The reactivity of heterometallic cluster complexes [ was investigated both in the absence and in the presence of water. According to 31 P NMR spectra, addition of the equimolar amount of P 4 to the solutions of these complexes in DMF, THF and CH 2 Cl 2 does not lead to transformation of P 4 molecule, and no new signals from phosphorus-containing species were detected.…”

“…The trinuclear cluster complexes with the {M 3 S 4 } (M = Mo, W) core are able to incorporate a range of transition metals in low oxidation state (from 0 to +2), affording heterometallic cubane-type derivatives {M 3 M S 4 }, where M = Cu, Ni, Pd, Pt, etc. [11,[30][31][32][33][34][35].…”

“…Indeed, addition of TlNO 3 as a halide scavenger increased the reactivity of the cluster towards P 4 . As a result, increased intensity of the signals related to H 3 PO 3 and H 3 PO 4 , and the decreased intensity of the P 4 signal were observed in 31 The solvent influence on the reactivity of P 4 and its hydrolysis was also investigated, using the complex 1 as the benchmark. Addition of an excess of H 2 O to the reaction mixture containing 1 and P 4 in CH 2 Cl 2 allowed for detection of the signals associated with [Mo 3 {PdP(OH) 3 }S 4 Cl 3 (dbbpy) 3 ] + (δ 110 ppm), H 3 PO 3 (δ 4.7 ppm) and H 3 PO 4 (δ 1.1 ppm).…”