Synthesis and characterisation of fifteen-electron dihalo(carbonyl)tungsten(iii) complexes, Tp*WX2(CO) (X = Br, I). Issue 71 (6th August 2020)

• Record Type: Journal Article
• Authors: Thomas, Simon; Gable, Robert W.; Young, Charles G.
• Is Part Of: Chemical communications. Volume 56:Issue 71(2020)
• Page Start: 10349
• Page End: 10352
• Publication Date: 2020-08-06
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/d0cc04607h
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : Open-shell, 15-electron, d 3 dihalo(carbonyl)–W III complexes, Tp*WX2 (CO), are reported. These mononuclear, distorted octahedral complexes exhibit single ν (CO) IR bands and magnetic moments and isotropically shifted NMR spectra consistent with low-spin, double ground states. Abstract : The oxidation of Tp*W II I(NCMe)(CO) [Tp* = hydrotris(3, 5-dimethylpyrazol-1-yl)borate] by iodine in refluxing acetonitrile produces paramagnetic Tp*W III I2 (CO), with μ eff = 1.70 μ B and ν (CO) = 1881 cm −1 . The analogous bromo complex, Tp*W III Br2 (CO) ( μ eff = 1.72 μ B, ν (CO) = 1905 cm −1 ), is produced by the oxidative decarbonylation of Tp*WI(CO)3 with bromoacetonitrile in refluxing tetrahydrofuran. The crystal structures of both complexes reveal mononuclear, six-coordinate, distorted octahedral metal complexes bearing facial Tp* and mutually cis halide and carbonyl ligands. The structures, magnetic moments and spectroscopic data (including isotropically shifted NMR spectra) are consistent with a low-spin, doublet ground state in these, the first reported, 15-electron, d 3 dihalo(carbonyl)–W(iii ) complexes.