Mechanistic behaviour of alkylcobaloximes and imino-oxime complexes related to vitamin B12

Alzoubi B, Vidali F, Puchta R, Dücker-Benfer C, Felluga A, Randaccio L, Tauzher G, van Eldik R (2009)

Publication Type: Journal article

Publication year: 2009

Journal

Pages Range: 2392-2399

Journal Issue: 13

DOI: 10.1039/b816511d

Abstract

The ligand substitution reactions of complexes of the type trans-[(R)Co(Chel)S]^+/0 with L, where chel = (DO)(DOH)pn = 2,2′-(1,3-diaminopropanebis(2-methyl-3-butanone)oxime), R = CH 3, L = imidazole, pyrazole, 1,2,4-triazole and 1-methylimidazole, and S = water and MeOH, and chel = (Hdmg)2 = bis(dimethylglyoximate), R = CH2Cl, CH2Br, and CH2I, L = thiourea and pyridine, and S = water, were studied in detail as a function of temperature and pressure. The reported activation parameters (ΔH^‡, ΔS^‡ and ΔV^‡) support the operation of a dissociative interchange (Id) mechanism. Complexes of the type trans-[RCo(Hdmg)2L] (R = CH2Cl, CH2Br, and CH2I; L = H2O and Py) were fully optimized at the B3LYP/LANL2DZp level, and the structural data support the mechanistic assignment based on the reported activation parameters. For the reaction of trans-[(CH3)2Co((DO)(DOH)pn)] with acid, the activation parameters (ΔH^‡, ΔS^‡ and ΔV^‡) were found to be 37 ± 1 kJ mol^-1, -86 ± 3 J mol^-1 K^-1 and -18.9 ± 0.7 cm ³ mol^-1, respectively, and support a protonation mechanism. © The Royal Society of Chemistry 2009.

Authors with CRIS profile

Involved external institutions

Università degli Studi di Trieste Italy (IT)

How to cite

APA:

Alzoubi, B., Vidali, F., Puchta, R., Dücker-Benfer, C., Felluga, A., Randaccio, L.,... van Eldik, R. (2009). Mechanistic behaviour of alkylcobaloximes and imino-oxime complexes related to vitamin B12. Dalton Transactions, 13, 2392-2399. https://doi.org/10.1039/b816511d

MLA:

Alzoubi, Basam, et al. "Mechanistic behaviour of alkylcobaloximes and imino-oxime complexes related to vitamin B12." Dalton Transactions 13 (2009): 2392-2399.

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