The synthesis of Mo(iv) arene complexes by the hydrogenation of Mo(iv) olefin complexesElectronic supplementary information (ESI) available: 1H NMR spectra for complexes 2b–2d and 2h, chemical shift data for 2a–2h. See http://www.rsc.org/suppdata/cc/b0/b007812n/

Abstract

The compounds [Mo(NPh)(η²-olefin)(o-(Me₃SiN)₂ C₆H₄)] (olefin = propene (1a), isobutene (1b), and butenes (1c)) react with molecular hydrogen (ca. 15 psi) in the presence of excess arene affording Mo(IV) η⁶-arene complexes of the type [Mo(NPh)(η⁶-arene)(o-(Me₃SiN)₂ C₆H₄)] (arene = benzene (2a), toluene (2b), o-xylene (2c), m-xylene (2d), p-xylene (2e), diphenylmethane (2f), and bibenzyl (2g)), while treatment of [Mo(NPh)(η²-styrene)(o-(Me₃SiN)₂ C₆H₄)] (1d) with hydrogen in a pentane solution gives [Mo(NPh)(η⁶-ethylbenzene)(o-(Me₃SiN) ₂C₆H₄)] (2h); the crystal structures of 2d and 2e are reported and reveal highly distorted arene ligands approaching η⁴-coordination modes.