Schindler, Kevin Crochet, Aurélien Zobi, Fabio 2021 New synthetic routes to aerobically stable and substitutionally labile α-diimine rhenium(I) dicarbonyl complexes are described. The molecules are prepared in high yield from the cis–cis–trans-[Re(CO)2(tBu2bpy)Br2]− anion (2, where tBu2bpy is 4,4′- di-tert-butyl-2,2′-bipyridine), which can be isolated from the one electron reduction of the corresponding 17-electron complex (1). Compound 2 is stable in the solid state, but in solution it is oxidized by molecular oxygen back to 1. Replacement of a single bromide of 2 by σ-donor monodentate ligands (Ls) yields stable neutral 18-electron cis–cis–trans-[Re(CO)2(tBu2bpy)Br(L)] species. In coordinating solvents like methanol the halide is replaced giving the corresponding solvated cations. [Re(CO)2(tBu2bpy)Br(L)] species can be further reacted with Ls to prepare stable cis– cis–trans-[Re(CO)2(tBu2bpy)(L)2]+ complexes in good yield. Ligand substitution of Re(I) complexes proceeds via pentacoordinate intermediates capable of Berry pseudorotation. In addition to the cis–cis–trans-complexes, cis–cis–cis- (all cis) isomers are also formed. In particular, cis–cis–trans-[Re(CO)2(tBu2bpy)(L)2]+ complexes establish an equilibrium with all cis isomers in solution. The solid state crystal structure of nearly all molecules presented could be elucidated. The molecules adopt a slightly distorted octahedral geometry. In comparison to similar fac- [Re(CO)3]+complexes, Re(I) diacarbonyl species are characterized by a bend (ca. 7°) of the axial ligands towards the α-diimine unit. [Re(CO)2(tBu2bpy)Br2]− and [Re(CO)2(tBu2bpy)Br(L)] complexes may be considered as synthons for the preparation of a variety of new stable diamagnetic dicarbonyl rhenium cis-[Re(CO)2]+ complexes, offering a convenient entry in the chemistry of the core. application/pdf https://folia.unifr.ch/global/documents/309288 https://folia.unifr.ch/documents/309288/files/zobi_et_al_2021_aerobically.pdf https://folia.unifr.ch/documents/309288/files/zobi_et_al_2021_aerobically_suppl.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1039/D1RA00514F info:eu-repo/semantics/openAccess License undefined RSC Advances. - 2021, vol. 11, p. 7511-7520 Rhenium Chemistry info:eu-repo/classification/udc/54 Aerobically stable and substitutionally labile α-diimine rhenium dicarbonyl complexes http://purl.org/coar/resource_type/c_6501