Alkyne complexes of tungsten(II) containing carboxylate and sulfonate substituted pyridine ligands. Water-soluble alkyne complexes of tungsten(II)

Abstract

Reaction of [WI 2(CO)(NCMe)(η 2-RC 2R) 2] (R=Me, Ph) with one equivalent of L{L=3-(CO 2Na)-py, 4-(CO 2Na)-py, 3,4-(CO 2Na) 2-py, 3,5-(CO 2Na) 2-py, 3-(SO 3Na)-py} in a mixture of CH 2Cl 2–CH 3OH (1:1 ratio) at room temperature gave the acetonitrile replaced products, [WI 2(CO)L(η 2-RC 2R) 2] ( 1– 10) in good yield. The 2-butyne complexes are slightly water-soluble, whereas the diphenylacetylene complexes are insoluble in water. Treatment of [WI 2(CO) 3(NCMe) 2] with two equivalents of propiolic acid (HC 2CO 2H) in CH 2Cl 2 at 0°C yields the bis(propiolic acid) complex [WI 2(CO)(NCMe)(η 2-HC 2CO 2H) 2] ( 11). Reaction of 11 with two equivalents of NaOH in MeOH–CH 2Cl 2 (1:1) affords the completely water-soluble complex, [WI 2(CO)(NCMe)(η 2-HC 2CO 2Na) 2] ( 12) in 58% yield. All the new complexes 1– 12 were characterised by elemental analysis (C, H, and N), IR and 1H NMR spectroscopy.