Energy transfer from an alkene triplet state during pulse radiolysis

Barwise, A.J.G.; Gorman, A. A.; Rodgers, Michael A. J.

doi:10.1016/0009-2614(76)85162-7

Cited by 25 publications

(29 citation statements)

References 8 publications

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“…The less symmetric NBN electronic structure in fact accounts for its unique molecular properties. Unlike NBD, the two single bonds, C (1) -C (2) and C (1) -C (6) of the NBN molecule are not equivalent anymore since the C (2) atom links to the CaC double bond and the C (6) atom relates to a C-C single bond in NBN. There are four types of non-equivalent C-C single bonds in NBN, namely, C (1) -C (2) , C (1) -C (6) , C (5) -C (6) , and C (1) -C (7) , which all stem from different bonding mechanisms (and cannot be produced by symmetry).…”

Section: Methano Ring In the Carbon Skeleton Of Nbnmentioning

confidence: 94%

“…The species are orientated in a way such that the methano carbon C (7) atom and its attached two hydrogen atoms lie in the xz-plane of the Cartesian coordinate system. The y-axis coincides with the line connecting atoms C (1) and C (4) , and in parallel with the C (2) -C (3) and C (5) -C (6) bonds; whereas the x-axis is perpendicular to those C-C bonds. In the case of NBN, the double bond is the C (2) -C (3) bond.…”

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 98%

“…In the carbon skeleton, angle :C (1) C (7) C (4) is called the bridge angle, which links to the single bonded carbon C (7) (methano carbon), whereas :HC (7) H, together with angles :HC (5) H and :HC (6) H in NBN and all :HC (2) H, :HC (3) H, :HC (5) H and :HC (6) H in NBA are called flap angles [4]. All those flap :HCH angles, except for the :HC (7) H angle, are positioned on the ethano ring.…”

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 99%

“…Hydrogen atoms of the flap angles in the bridge side are called exo-Hs (or H exo ) and those towards the other side of the bridge are called endo-Hs (or H endo ) [1]. In NBN the H atom, which forms the :HC (7) H angle and points to the C (5) -C (6) single bond, is called H a (asymmetric), while the other H atom is therefore symmetric to the CaC bond and is called H s [29]. It is noted that strained structures [25] contain atoms with bond angles departing from the standard bond angles of 109.47 and 120.008, with respect to sp 3 and sp 2 hybrid carbon orbitals.…”

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 99%

“…The experimental exo-reactivity related to the double bond of the NBN molecule has puzzled chemists for many years [5]. Norbornene is considered as one of the prototype strained olefins, due to its extreme chemical reactivity, undergoing elimination, dimerisation, addition and isomerisation [6], as well as exo-selectivity [7]. Norbornadiene (NBD), on the other hand, is an unconjugated, strained and non-planar diene.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Structural impact on the methano bridge in norbornadiene, norbornene and norbornane

Wang

Brunger

Winkler

2004

Journal of Physics and Chemistry of Solids

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Section: Methano Ring In the Carbon Skeleton Of Nbnmentioning

confidence: 94%

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 98%

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 99%

Section: Molecule Orientation In Space and Computational Detailsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Structural impact on the methano bridge in norbornadiene, norbornene and norbornane

Wang

Brunger

Winkler

2004

Journal of Physics and Chemistry of Solids

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Mechanistic Studies on Uranyl Ion Initiated Photopolymerization of Acrylamide

Faria

Formosinho

Miguel

et al. 1992

Ber Bunsenges Phys Chem

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The mechanism of the uranyl ion photoinitiated polymerization of acrylamide has been studied in aqueous solutions and in acetone. Steady‐state and dynamic luminescence quenching studies show that initiation proceeds through a thermally activated bimolecular interaction between *UO22+ and monomer involving electron or charge transfer. Results from various studies show that the mechanism previously suggested for this process, involving energy transfer, is incorrect. ESR studies suggest that initiation involves formation of a uranium(V)‐radical pair. Polymerization then proceeds through a radical mechanism in both solvents. With the exception of the chloride, the yields do not depend upon the counter‐ion. Polymer is frequently produced with adsorbed uranyl ions, which can be separated by dialysis. In agreement with previous studies, photopolymerization proceeds without significant overall reduction in the uranyl concentration. It is shown that this is probably due to any intermediate uranium(V) being reoxidized by monomer, with concurrent thermal initiation of polymerization.

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Mechanistic Insights into the Substrate‐Controlled Stereochemistry of Glycals in One‐Pot Rhodium‐Catalyzed Aziridination and Aziridine Ring Opening

Lorpitthaya

Xie

Sophy

et al. 2009

Chemistry A European J

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We carried out a principle study on the reaction mechanism of rhodium-catalyzed intramolecular aziridination and aziridine ring opening at a sugar template. A sulfamate ester group was introduced at different positions of glycal to act as a nitrene source and, moreover, to allow the study of the relative reactivity of the nitrene transfer from different sites of the glycal molecule. The structural optimization of each intermediate along the reaction pathway was extensively done by using BPW91 functional. The crucial step in the reaction is the Rh-catalyzed nitrene transfer to the double bond of the glycal. We found that the reaction could proceed in a stepwise manner, whereby the N atom initially induced a single-bond formation with C1 on the triplet surface or in a single step through intersystem crossing (ISC) of the triplet excited state of the rhodium-nitrene transition state to the singlet ground state of the aziridine complexes. The relative reactivity for the conversion of the nitrene species to the aziridine obtained from the computed potential energy surface (PES) agrees well with the reaction time gained from experimental observation. The aziridine ring opening is a spontaneous process because the energy barrier for the formation of the transition state is very small and disappears in the solution calculations. The regio- and stereoselectivity of the reaction product is controlled by the electronic property of the anomeric carbon as well as the facial preference for the nitrene insertion, and the nucleophilic addition.

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Energy transfer from an alkene triplet state during pulse radiolysis

Cited by 25 publications

References 8 publications

Structural impact on the methano bridge in norbornadiene, norbornene and norbornane

Structural impact on the methano bridge in norbornadiene, norbornene and norbornane

Mechanistic Studies on Uranyl Ion Initiated Photopolymerization of Acrylamide

Mechanistic Insights into the Substrate‐Controlled Stereochemistry of Glycals in One‐Pot Rhodium‐Catalyzed Aziridination and Aziridine Ring Opening

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