Complexes of Ambidentate N,O-Donor Ligands with Rhenium(I) and -(V)

Abstract

The reaction of the potentially bidentate ambidentate N,O-donor ligands 3-hydroxy-2-pyridinecarboxylic acid (Hhpc) and 3-hydroxy-2-(hydroxymethyl)pyridine (Hhhp) with trans-[ReOCl3(PPh3)2] led to the isolation of the products [ReOCl(hpc)2] (1) (from acetonitrile) and [ReOCl2(hhp)(PPh3)] (2) (from ethanol) respectively. In both complexes hpc and hhp are coordinated as bidentate N,O-donor chelates, rather than as O,O-donor ligands. From the reaction of [Re(CO)5Cl] and Hhhp·HCl in ethanol the neutral complex fac-[Re(CO)3Cl(Hhhp)] (3) was obtained, with N,O-coordination of Hhhp. Complex 1 crystallizes in the monoclinic space group P21/n with a = 6.8782(3), b = 20.0647(8), c = 10.8692(4) Å, β = 107.545(1)°, and Z = 4. Complex 2 crystallizes in the triclinic space group P-1 with a = 7.3523(4), b = 8.1047(5), c = 19.591(1) Å, α = 91.133(2)°, β = 93.656(2)°, γ = 93.074(2)° and Z = 2. Complex 3 has monoclinic P21/c symmetry with the cell parameters a = 10.6452(5), b = 11.1372(5), c = 9.7229(5) Å, β = 106.107(2)°, and Z = 4. Graphical Abstract: The reaction of the potentially bidentate ambidentate N,O-donor ligands 3-hydroxy-2-pyridinecarboxylic acid (Hhpc) and 3-hydroxy-2-(hydroxymethyl)pyridine (Hhhp) with trans-[ReOCl3(PPh3)2] led to the isolation of the products [ReOCl(hpc)2] (from acetonitrile) and [ReOCl2(hhp)(PPh3)] (from ethanol) respectively. In both complexes hpc and hhp are coordinated as bidentate N,O-donor chelates, rather than as O,O-donor ligands. From the reaction of [Re(CO)5Cl] and Hhhp·HCl in ethanol the neutral complex fac-[Re(CO)3Cl(Hhhp)] was obtained, with N,O-coordination of Hhhp. Spectroscopic data and the X-ray crystal structures of the complexes are reported. [Figure not available: see fulltext.].