Browsing by Author "Kevin, Lam"

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    Corrigendum to “Synthesis and anodic electrochemistry of cymanquine and related complexes” [J. Organomet. Chem. 817 (15 August 2016) 15–20]
    (Journal of Organometallic Chemistry, 2017-05-15) Lam, Kevin; Geiger, William E.; Kevin, Lam
    The authors regret that the oxidation potentials given for compound 5 in the paper are incorrect. The correct values, referenced to ferrocene, are 0.88 V for the first oxidation and 1.14 V for the second oxidation.
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    One-electron oxidation of chloroquine, cymanquine, and related aminoquinolines in nonaqueous media
    (Journal of Electroanalytical Chemistry, 2017-08-15) Lam, Kevin; Van Wyck, Stephen J.; Geiger, William E.; Kevin, Lam
    Abstract The anodic oxidation of a series of secondary-amine-substituted chloroquinoline derivatives, 1–5, has been studied in dichloromethane/0.05M [NBu4][B(C6F5)4]. Compounds 4 and 5 contain organometallic moieties of the cymantrene family as part of the amine group. All five compounds undergo an electrochemically irreversible one-electron oxidation. For compounds 2–4, this occurs at the secondary amine group (0.86 to 0.98V vs ferrocene). The oxidations of others occur at tertiary amines located either in the side chain of the quinoline secondary amine (1, 0.68V) or in the cyclopentadienyl ring of the cymantrene moiety (5, 0.82V). The anodic reaction products have been isolated and shown to be ring-nitrogen protonated aminochloroquinolinium ions. Abstraction of a hydrogen atom from the solvent by the putative aminochloroquinoline radical cation is thought to be responsible for formation of the protonated oxidation product. Cathodic reduction of the latter regenerates the neutral starting material in an overall chemically reversible process that mimics a simple acid/base reaction at the quinoline ring nitrogen.
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    Synthesis and anodic electrochemistry of cymanquine and related complexes
    (Journal of Organometallic Chemistry, 2016-08-15) Lam, Kevin; Geiger, William E.; Kevin, Lam
    Abstract Three compounds have been prepared in which a 4-aminochloroquinoline moiety is covalently linked to a cyclopentadienyl manganese tricarbonyl moiety. One of these (“cymanquine”, 4) is the analogue of the potent antimalarial drug ferroquine in which an FeCp group has been replaced by a Mn(CO)3 group. The anodic electrochemistry of the new compounds was investigated in dichloromethane, using [NBu4][B(C6F5)4] as the supporting electrolyte. Compared to ferroquine, oxidations of the new compounds occur at considerably more positive potentials and are highly irreversible, being located at their amine groups rather than at the organometallic center.