Quantum mechanical studies of the protonation and NBr bond dissociation of the biologically important N-bromosuccinimide

Elroby, Shaaban A.; Noamaan, Mahmoud A.; Shibl, Mohamed F.

doi:10.1016/j.theochem.2009.08.024

Cited by 3 publications

(1 citation statement)

References 31 publications

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“…Beginning with the BDE of the ubiquitous brominating agent N ‐bromosuccinimide ( 19 ), we compute a value of 281.6 kJ mol −1 , which is in reasonable agreement with the experimentally reported value of 276.1 ± 8.4 kJ mol −1 . We wish to mention that the previously reported BDE of 265.2 kJ mol −1 (obtained at the B3LYP/6‐311++G(d,p) level) appears to be too low, and this is consistent with our findings that B3LYP significantly underestimates NBr BDEs (Table ). Increasing the ring size from five to six, as in N ‐bromoglutarimide ( 20 ) results in a significant decrease in the strength of the NBr bond (by 18.4 kJ mol −1 ).…”

Section: Resultssupporting

confidence: 89%

A dataset of highly accurate homolytic NBr bond dissociation energies obtained by Means of W2 theory

O'Reilly

Karton

2015

Int J of Quantum Chemistry

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Homolytic NBr bond dissociation constitutes the initial step of numerous reactions involving N‐brominated species. However, little is known about the strength of NBr bonds toward homolytic cleavage. We herein report accurate bond dissociation energies (BDEs) for a set of 18 molecules using the high‐level W2 thermochemical protocol. The BDEs (at 298 K) of the species in this set range from 162.2 kJ mol−1 (N‐bromopyrrole) to 260.6 kJ mol−1 ((CHO)2NBr). In order to compute BDEs of larger systems, for which W2 theory is not applicable, we have benchmarked a wide range of more economical theoretical procedures. Of these, G3‐B3 offers the best performance (root‐mean‐square deviations = 2.9 kJ mol−1), and using this method, we have computed NBr BDEs for four widely used N‐brominated compounds. These include (BDEs are given in parentheses): N‐bromosuccinimide (281.6), N‐bromoglutarimide (263.2), N‐bromophthalimide (274.7), and 1,3‐dibromo‐5,5‐dimethylhydantoin (218.2 and 264.8 kJ mol−1). © 2015 Wiley Periodicals, Inc.

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Section: Resultssupporting

confidence: 89%

A dataset of highly accurate homolytic NBr bond dissociation energies obtained by Means of W2 theory

O'Reilly

Karton

2015

Int J of Quantum Chemistry

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Two-step one-electron transfer reaction of chromium(III) complex containing levodopa and uridine with N-bromosuccinimide

Abdelkhalek

Adawi²,

Abdel-Hafeez³

2012

Journal of Coordination Chemistry

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Cr III (LD)(Urd)(H 2 O) 4 ](NO 3 ) 2 Á 3H 2 O (LD ¼ Levodopa; Urd ¼ uridine) was prepared and characterized. The product of the oxidation reaction was examined using HPLC. Kinetics of the oxidation of [Cr III (LD)(Urd)(H 2 O) 4 ] 2þ with N-bromosuccinimide (NBS) in an aqueous solution was studied spectrophotometrically, with 1.0-5.0 Â 10 À4 mol dm À3 complex, 0.5-5.0 Â 10 À2 mol dm À3 NBS, 0.2-0.3 mol dm À3 ionic strength (I), and 30-50 C. The reaction is first order with respect to [Cr III ] and [NBS], decreases as pH increases in the range 5.46-6.54 and increases with the addition of sodium dodecyl sulfate (SDS, 0.0-1.0 Â 10 À3 mol dm À3 ). Activation parameters including enthalpy, DH*, and entropy, DS*, were calculated. The experimental rate law is consistent with a mechanism in which the protonated species is more reactive than its conjugate base. It is assumed that the two-step one-electron transfer takes place via an inner-sphere mechanism. A mechanism for this reaction is proposed and supported by an excellent isokinetic relationship between DH* and DS* for some Cr III complexes. Formation of [Cr III (LD)(Urd)(H 2 O) 4 ] 2þ in vivo probably occurs with patients who administer the anti-Parkinson drug (Levodopa), since Cr III is a natural food element. This work provides an opportunity to identify the nature of such interactions in vivo similar to that in vitro.

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Selective Recovery of AU from Waste Printed Circuit Board by Water-Soluble Organic Leaching: The Key Role of in Situ Bromine Mediation and Identification of Pathway

Xiong,

Huang,

et al. 2024

Preprint

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Quantum mechanical studies of the protonation and NBr bond dissociation of the biologically important N-bromosuccinimide

Cited by 3 publications

References 31 publications

A dataset of highly accurate homolytic NBr bond dissociation energies obtained by Means of W2 theory

A dataset of highly accurate homolytic NBr bond dissociation energies obtained by Means of W2 theory

Two-step one-electron transfer reaction of chromium(III) complex containing levodopa and uridine with N-bromosuccinimide

Selective Recovery of AU from Waste Printed Circuit Board by Water-Soluble Organic Leaching: The Key Role of in Situ Bromine Mediation and Identification of Pathway

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