Studies of the formation and stability of pentadienyl and 3-substituted pentadienyl radicals

Clark, K. B.; Culshaw, Peter N.; Griller, D.; Lossing, F. P.; Simões, José A. Martinho; Walton, John C.

doi:10.1021/jo00019a012

Cited by 54 publications

(51 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is indicated by the C-H BDE of 1,4-pentadiene, which was measured experimentally to be 76.6G1.0 kcal/mol. 31 1,4-pentadiene is C5.2 kcal/mol, which is in agreement with our result.…”

Section: Extra Substitution Effects On Bdessupporting

confidence: 93%

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

2004

View full text Add to dashboard Cite

“…This is indicated by the C-H BDE of 1,4-pentadiene, which was measured experimentally to be 76.6G1.0 kcal/mol. 31 1,4-pentadiene is C5.2 kcal/mol, which is in agreement with our result.…”

Section: Extra Substitution Effects On Bdessupporting

confidence: 93%

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

2004

View full text Add to dashboard Cite

“…Lipoxygenases (LO) 29–31 use M(III)−OH (M = Fe, Mn) to regio- and stereospecifically abstract a H atom from the allylic C−H bond of a fatty acid (BDE ≈ 77 kcal/mol). 32 The LO resting state has been shown to contain a reduced monomeric Fe(II)−H 2 O in an N 4 O coordination sphere (Figure 1). 30, 33–35 The catalytically active form of LO contains a monomeric Fe(III)−OH (or Mn(III)−OH).…”

Section: Introductionmentioning

confidence: 99%

Water-Soluble Fe(II)–H₂O Complex with a Weak O–H Bond Transfers a Hydrogen Atom via an Observable Monomeric Fe(III)–OH

et al. 2015

View full text Add to dashboard Cite

Understanding the metal ion properties that favor O−H bond formation versus cleavage should facilitate the development of catalysts tailored to promote a specific reaction, e.g., C−H activation or H2O oxidation. The first step in H2O oxidation involves the endothermic cleavage of a strong O−H bond (BDFE = 122.7 kcal/mol), promoted by binding the H2O to a metal ion, and by coupling electron transfer to proton transfer (PCET). This study focuses on details regarding how a metal ion’s electronic structure and ligand environment can tune the energetics of M(HO−H) bond cleavage. The synthesis and characterization of an Fe(II)−H2O complex, 1, that undergoes PCET in H2O to afford a rare example of a monomeric Fe(III)−OH, 7, is described. High-spin 7 is also reproducibly generated via the addition of H2O to {[FeIII(OMe2N4(tren))]2-(µ-O)}2+ (8). The O−H bond BDFE of Fe(II)−H2O (1) (68.6 kcal/mol) is calculated using linear fits to its Pourbaix diagram and shown to be 54.1 kcal/mol less than that of H2O and 10.9 kcal/mol less than that of [Fe(II)(H2O)6]2+. The O−H bond of 1 is noticeably weaker than the majority of reported Mn+(HxO−H) (M = Mn, Fe; n+ = 2+, 3+; x = 0, 1) complexes. Consistent with their relative BDFEs, Fe(II)−H2O (1) is found to donate a H atom to TEMPO•, whereas the majority of previously reported Mn+−O(H) complexes, including [MnIII(SMe2N4(tren))(OH)]+ (2), have been shown to abstract H atoms from TEMPOH. Factors responsible for the weaker O−H bond of 1, such as differences in the electron-donating properties of the ligand, metal ion Lewis acidity, and electronic structure, are discussed.

show abstract

“…24 This situation is reminiscent of the formation of pentadienyl radicals. 25 Nevertheless, in contrast to 1,5-hydrogen transfer, 26 1,4-hydrogen atom transfer is less frequently observed 27,28 and such a competition with cyclization was neglected here. …”

Section: Resultsmentioning

confidence: 96%

Clear-cut difference in the rearrangement of 1-bromo-2-(2-phenyl-3-butenyl)benzene under anionic or radical conditions

Reynaud¹,

Hazimeh²,

Mattalia³

et al. 2011

Arkivoc

View full text Add to dashboard Cite

The o-(3-butenyl)phenyl system bearing a phenyl group on the 2-position of the side chain was studied as a potential mechanistic probe for distinguishing between radical and carbanion intermediates. The Bu3SnH reduction of 1-bromo-2-(2-phenyl-3-butenyl)benzene, 4, yields mainly the 1,5-cyclization product, 6, with a preference for the trans-isomer. Treatment of 4 with Mg or t-BuLi leads to double-bond isomerization and yields (E)-1,2-diphenyl-2-butene, 8, along with 3,4-diphenyl-1-butene, 5.

show abstract

Studies of the formation and stability of pentadienyl and 3-substituted pentadienyl radicals

Cited by 54 publications

References 3 publications

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

Water-Soluble Fe(II)–H₂O Complex with a Weak O–H Bond Transfers a Hydrogen Atom via an Observable Monomeric Fe(III)–OH

Clear-cut difference in the rearrangement of 1-bromo-2-(2-phenyl-3-butenyl)benzene under anionic or radical conditions

Contact Info

Product

Resources

About

Studies of the formation and stability of pentadienyl and 3-substituted pentadienyl radicals

Cited by 54 publications

References 3 publications

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

Effects of geminal disubstitution on C–H and N–H bond dissociation energies

Water-Soluble Fe(II)–H2O Complex with a Weak O–H Bond Transfers a Hydrogen Atom via an Observable Monomeric Fe(III)–OH

Clear-cut difference in the rearrangement of 1-bromo-2-(2-phenyl-3-butenyl)benzene under anionic or radical conditions

Contact Info

Product

Resources

About

Water-Soluble Fe(II)–H₂O Complex with a Weak O–H Bond Transfers a Hydrogen Atom via an Observable Monomeric Fe(III)–OH