Highly Reduced Ruthenium Carbide Carbonyl Clusters: Synthesis, Molecular Structure, Reactivity, Electrochemistry, and Computational Investigation of [Ru₆C(CO)₁₅]⁴.

ABSTRACT: The reaction of [Ru₆C(CO)₁₆]^2- (1) with NaOH in DMSO resulted in the formation of a highly reduced [Ru₆C(CO)₁₅]^4- (2), which was readily protonated by acids, such as HBF₄·Et₂O, to [HRu₆C(CO)₁₅]^3- (3). Oxidation of 2 with [Cp₂Fe][PF₆] or [C₇H₇][BF₄] in CH₃CN resulted in [Ru₆C(CO)₁₅(CH₃CN)]^2- (5), which was quantitatively converted into 1 after exposure to CO atmosphere. The reaction of 2 with a mild methylating agent such as CH_3,I afforded the purported [Ru₆C(CO)₁₄(COCH₃)]^3- (6). By employing a stronger reagent, that is, CF₃SO₃CH₃, a mixture of [HRu₆C(CO)₁₆]^- (4), [H₃Ru₆C(CO)₁₅]^- (7), and [Ru₆C(CO)₁₅(CH₃CNCH₃)]^- (8) was obtained. The molecular structures of 2-5, 7, and 8 were determined by single-crystal X-ray diffraction as their [NEt₄]₄[2]·CH₃CN, [NEt₄]₃[3], [NEt₄][4], [NEt₄]₂[5], [NEt₄][7], and [NEt₄][8]·solv salts. The carbyne-carbide cluster 6 was partially characterized by IR spectroscopy and ESI-MS, and its structure was computationally predicted using DFT methods. The redox behavior of 2 and 3 was investigated by electrochemical and IR spectroelectrochemical methods. Computational studies were performed in order to unravel structural and thermodynamic aspects of these octahedral Ru-carbide carbonyl clusters displaying miscellaneous ligands and charges in comparison with related iron derivatives.

SUBMITTER: Cesari C 

PROVIDER: S-EPMC10498495 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature