Propene complexes of molybdenum and tungsten stabilized by intramolecular coordination of the 1-(quinol-8-yl)indenyl ligand

• Published in: Dalton transactions : an international journal of inorganic chemistry 2019-08, Vol.48 (32), p.1221-12218
• Main Authors: Mrózek, Ond ej, Dostál, Libor, Císa ová, Ivana, Honzí ek, Jan, Vinklárek, Jaromír
• Format: Article
• Language: English
• Subjects: Acetonitrile; Coordination compounds; Crystallography; Dimethyl sulfide; Donors (electronic); Ligands; Molybdenum; Protonation; Tungsten compounds
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c9dt02229e

We report herein a new class of mixed propene-indenyl complexes of molybdenum and tungsten stabilized by a strong N→M intramolecular coordination. The complexes [{η 5 :κ N -1-(C 9 H 6 N)C 9 H 6 }(η 2 -C 3 H 6 )M(CO) 2 ][BF 4 ] (M = Mo, W) were obtained in nearly quantitative yields by the protonation of the η 3 -allyl ligand in compounds [(η 3 -C 3 H 5 ){η 5 -1-(C 9 H 6 N)C 9 H 6 }M(CO) 2 ] (M = Mo, W). In contrast to known η 2 -alkene molybdenum and tungsten compounds, the species presented here are easily isolated in the solid state. The tungsten compound [{η 5 :κ N -1-(C 9 H 6 N)C 9 H 6 }(η 2 -C 3 H 6 )W(CO) 2 ][BF 4 ] is stable at room temperature, and its structure was unambiguously confirmed by X-ray diffraction. The reactivity of both propene complexes toward several monodentate donors was examined. In the case of dimethyl sulfide, ligand exchange takes place to afford [{η 5 :κ N -1-(C 9 H 6 N)C 9 H 6 }M(CO) 2 (SMe 2 )][BF 4 ] (M = Mo, W) while acetonitrile induces η 5 → η 3 haptotropic rearrangement to give [{η 3 :κ N -1-(C 9 H 6 N)C 9 H 6 }M(CO) 2 (NCMe) 2 ][BF 4 ] (M = Mo, W). Synthesis, reactivity and properties of unusually stable propene complexes of molybdenum and tungsten are reported.