Half-Sandwich Arene-Osmium(II) Complexes with Phosphinite Ligands

Abstract

The synthesis of a series of arene-osmium(II) complexes containing phosphinite-type ligands, namely, [OsCl 2 (η 6 -p-cymene){R 2 PO(CH 2 ) n Ph}] (R = Ph, n = 1 (4a), 2 (4b), 3 (4c); R = i Pr, n = 1 (5a), 2 (5b), 3 (5c)) and [OsCl 2 (η 6 -benzene){ i Pr 2 PO(CH 2 ) 2 Ph}] (7), is presented. All these compounds were characterized by elemental analysis and multinuclear NMR spectroscopy ( 31 P{ 1 H}, 1 H and 13 C{ 1 H}), and the structure of [OsCl 2 (η 6 -p-cymene){Ph 2 PO(CH 2 ) 3 Ph}] (4c) unequivocally confirmed through a single-crystal X-ray diffraction study. Attempts to generate the tethered species [OsCl 2 {η 6 :κ 1 (P)-C 6 H 5 (CH 2 ) n OPR 2 }] by intramolecular exchange of the coordinated arene in 4-5a-c or 7, upon thermal or MW heating, failed. Abstract:The synthesis of a series of arene-osmium(II) complexes containing phosphinite-type ligands, namely, [OsCl2(η 6 -p-cymene){R2PO(CH2)nPh}] (R = Ph, n = 1 (4a), 2 (4b), 3 (4c); R = i Pr, n = 1 (5a), 2 (5b), 3 (5c)) and [OsCl2(η 6 -benzene){ i Pr2PO(CH2)2Ph}] (7), is presented. All these compounds were characterized by elemental analysis and multinuclear NMR spectroscopy ( 31 P{ 1 H}, 1 H and 13 C{ 1 H}), and the structure of [OsCl2(η 6 -p-cymene){Ph2PO(CH2)3Ph}] (4c) unequivocally confirmed through a single-crystal X-ray diffraction study. Attempts to generate the tethered species [OsCl2{η 6 :κ 1 (P)-C6H5(CH2)nOPR2}] by intramolecular exchange of the coordinated arene in 4-5a-c or 7, upon thermal or MW heating, failed.