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The reaction of Re(CO)3(H2O)3+ with hen egg lysozyme in aqueous solution results in a single covalent adduct; single crystal X-ray diffraction shows that the rhenium tricarbonyl cation binds to His15 in two significantly populated rotamer conformations.

The reaction of Re(CO)(3)(H(2)O)(3)(+) with hen egg white lysozyme in aqueous solution results in a single covalent adduct. Both NMR spectroscopy and single crystal X-ray diffraction show that the rhenium tricarbonyl cation binds to His15 via replacement of one of the coordinated water molecules. The formation of this adduct does not greatly affect the structure of the protein.

A series of dimeric ReI(CO)3 compounds have been prepared by means of a one‐pot reaction of [Re(CO)5X] (X = Cl, Br), pyridine‐2‐carboxyaldehyde, and o‐, m‐, or p‐phenylenediamine. For the m‐ and p‐substituted phenylenediamine reactions, phenyl‐bridged bis(pyridine‐2‐carbaldimine) compounds of the formula [Re(CO)3X]2(μ‐PPC) [3–7; X = Cl, Br; μ‐PPC = m‐ or p‐phenylene bis(pyridine‐2‐carbaldimine)] were produced, with m‐phenylenediamine forming a mixture of isomers. For reactions with o‐phenylenediamine, multiple products formed (compounds 8–11), which ranged from the desired o‐phenylene bis(pyridine‐2‐carbaldimine) adduct to 2‐pyridylbenzimidazole and bridging dipyridinylquinoxaline complexes. An example of each complex was structurally elucidated by single‐crystal X‐ray methods. The dimeric m‐ and p‐phenylene‐bridged Re(CO)3X compounds, including a sulfonate derivative designed to improve solubility, were investigated for possible photophysical applications through the use of UV/Vis spectroscopy and cyclic voltammetry; the study revealed coupling between the rhenium centers.

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The reactions of ammonia, pyridine (py), N-methyl imidazole (N-MeIm), tetrahydrothiophene (tht), and piperidine (pip) with Re(CO) 3(H 2O) 3 (+), 1 ( + ), were investigated employing aqueous conditions under atmospheric dioxygen. The reaction of [ 1]Br in aqueous ammonia led to [Re(CO) 3(NH 3) 3]Br ([ 2]Br) as the only product isolated. For the aqueous reactions of [ 1]Br with py, N-MeIm, and tht, mixtures of products are formed because of competition between the bromide and added ligand, even when the ligand is present in excess. Substitution of the PF 6 (-) anion for Br (-) leads to the clean formation of [Re(CO) 3L 3][PF 6] ([ 3][PF 6]-[ 5][PF 6]) for py, N-MeIm, and tht, respectively, as the only products observed. Reaction of [ 1][PF 6] with pip produces the dimeric species, (pip)(CO) 3Re(micro-OH) 2Re(CO) 3(pip), 6. Reactions of [ 1]Br were also performed in methanol for comparison purposes. The reaction with pip in this solvent led to the analogous dimer, (pip)(CO) 3Re(micro-OMe) 2Re(CO) 3(pip), 7; however, reactions with py, N-MeIm, and tht gave Re(CO) 3L 2Br, 8- 10, respectively, as the only products. The crystal structures of compounds [ 2]Br- 10 are reported.

The aqueous one-step reaction of Re(CO)(3)(H(2)O)(3)(+) with pyridine-2-carboxyaldehyde and glycine or alanine produces a new class of cyclic dimeric products. The ligands of the chiral C(2)-symmetric products are bound via the diimine at one rhenium centre and via the pendant carboxylate to a second rhenium center.