Reactivity of 1‐Nitroso‐2‐naphthol Towards the Carbonyl Complexes XRe(CO)₅ (X = Cl, Br, I): Molecular Structures of cis‐[η²‐{N,O‐C₁₀H₆ON(O)}Re(CO)₄] and fac‐[η²‐{N,O‐C₁₀H₆ON(H)}Re(CO)₃X]

Abstract

The halogeno complexes (CO)5ReX (1a–c) (X = Cl, Br, I) react with 1‐nitroso‐2‐naphthol C10H6N(O)OH (2) in refluxing CH2Cl2 to give the substitution product cis‐(CO)4Re{C10H6ON(O)} (3) via HX and CO elimination in good yield. Compound 3 is coordinated to the Re centre by the bidentate chelate ligand via the N‐atom of the nitroso and O‐atom of the naphtholato groups. The same reaction in refluxing toluene, however, gave no HX elimination but instead, the fac‐(CO)3XRe{C10H6ON(H)} (4–6) complexes are formed, which contain the rare, N,O‐chelating ligand 1,2‐naphthaquinone‐2‐imine. The nitroso function of 2 has been reduced to the imine function by an intermolecular redox process, which was confirmed by the detection of CO2 generated during the reaction. The new compounds 3–6 have been characterised by their IR, 1H and 13C NMR, UV/Vis and mass spectra, as well as by X‐ray structure analyses. The ReI centres show a distorted octahedral coordination of the CO and X (in 4–6) ligands and the almost planar aromatic (3) or quinoid (4–6) N,O chelating ligands. (© Wiley‐VCH Verlag GmbH & Co. KgaA, 69451 Weinheim, Germany, 2005)

Tautomerization of 2-nitroso-N-arylanilines by coordination as N,N′-chelate ligands to rhenium(i) complexes and the anticancer activity of newly synthesized oximine rhenium(i) complexes against human melanoma and leukemia cells in vitro☆

“…In this context the convenient availability of 2-nitroso-N-arylanilines [22] has drawn our attention from N,O-bridging [23][24][25] andchelating [26] to N,N′-chelating ligands. Before 2007 this class of compounds was mostly reported as a by-product [27][28][29].…”

Absence of Dichroism in Dinuclear Rhenium Complexes with Sterically Hindered μ2‐(η2‐N,O)‐Nitrosobenzene Ligands

“…A considerably different reaction pathway has been found for the reaction of [Re(CO) 5 X] (X = Cl, Br, I) with more sterically demanding C ‐nitroso ligands (e.g. 1‐nitroso‐2‐naphthol), whereby HX or CO 2 elimination has been observed, and quite different mononuclear products have been obtained 9…”