Monomer–Dimer solution equilibria of 2,4,6-trialkylnitrosobenzenes and 2,4,6-trialkylnitrosobenzene/nitrosobenzene mixtures. A study using one- and two-dimensional NMR techniques

Orrell, Keith G.; Stephenson, David S.; Verlaque, J. H.

doi:10.1039/p29900001297

Cited by 17 publications

(7 citation statements)

References 22 publications

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“…When geometric isomerism is taken into account, it follows that six unique azodioxides can result from the combination of two different nitrosoarenes (eq ). Obviously, detailed studies of crossed dimerization are challenging, especially when the processes do not show high selectivity. , …”

Section: Crossed Dimerization Of Nitrosoarenesmentioning

confidence: 99%

“…Obviously, detailed studies of crossed dimerization are challenging, especially when the processes do not show high selectivity. 201,203 However, as described above, crossed dimerization can produce heterodimers selectively when steric hindrance inhibits formation of the homodimers of one of the two partners. This phenomenon is not limited to the combination of nitrosoarenes and nitrosoalkanes, as in the case illustrated earlier.…”

Section: Crossed Dimerization Of Nitrosoarenesmentioning

confidence: 99%

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Dimerization of Aromatic C-Nitroso Compounds

2016

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Aromatic C-nitroso compounds (Ar-N═O) and related species have a rich chemical history, and they continue to interest researchers in many fields. Among the most distinctive and puzzling properties of these compounds is their ability to dimerize reversibly to form azodioxy compounds. The present review subjects this intriguing phenomenon to comprehensive analysis. All aspects of the subject are examined in detail, including the structures of monomeric and dimeric forms, the mechanism of dimerization, features that favor or disfavor dimerization, thermodynamic and kinetic factors, dimerization under specific conditions (including in solution, in the solid state, and on surfaces), and the special associative behavior of dinitroso and polynitroso compounds. By summarizing the current state of knowledge, the review promises to spur further advances in the evergreen field of C-nitroso chemistry, including the discovery of new ways to exploit the reversible dimerization of nitrosoarenes.

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Section: Crossed Dimerization Of Nitrosoarenesmentioning

confidence: 99%

Section: Crossed Dimerization Of Nitrosoarenesmentioning

confidence: 99%

Dimerization of Aromatic C-Nitroso Compounds

2016

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“…24 NMR techniques have been successfully used previously to study the equilibria of several systems including mixed dimer systems. [25][26][27] This earlier work has now been extended to the present nitrosobenzene derivatives. From the relative populations of all three solution species at several temperatures in the range 303 to 213 K, equilibrium constants, K ---, for the dissociations of both types of dimers have been calculated.…”

Section: Monomer-dimer Equilibria-thermodynamic Studiesmentioning

confidence: 94%

Structural investigations of C-nitrosobenzenes. Part 2.1 NMR studies of monomer–dimer equilibria including restricted nitroso group rotation in monomers

Fletcher¹,

Gowenlock²,

Orrell³

1998

J. Chem. Soc., Perkin Trans. 2

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Energy barriers associated with rotation of nitroso groups in monomeric nitrosobenzene and eleven monomeric substituted nitrosobenzenes in solution have been measured by total 1 H NMR bandshape analysis. G ‡ (298.15 K) values for the rotations are in the range 31-41 kJ mol Ϫ1 . The values for 4substituted compounds correlate well with the Hammett p ؉ parameter for the substituent. The experimental energy barrier for nitrosobenzene is compared with theoretical calculations. Monomerdimer equilibria of these compounds in solution have been investigated, with H ---, S --and G --data calculated for the dissociation of both Z-and E-azodioxy dimers to monomers. Kinetic data, based on time-dependent and two-dimensional exchange spectroscopy (2D-EXSY) NMR measurements, have been obtained for the dissociation of 3-methylnitrosobenzene and 3,5-dimethylnitrosobenzene dimers. Energy profiles for the ground and transition states of both dimers and monomers (including exchange between both their rotameric forms) are discussed. Paper 7/08653I

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“…Although this kind of molecules commonly lack stability, 76 the synthesis of photostable derivatives is feasible 77 . Other molecules that fulfill the energy requirements, such as 78301‐05‐0, are not recommendable for singlet fission due the low melting point of this kind of materials 78,79 …”

Section: F5: Quinodimethanesmentioning

confidence: 99%

A new protocol for the identification of singlet fission sensitizers through computational screening

López‐Carballeira

Polcar

2021

J Comput Chem

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Although singlet fission presents deep advantages or the generation of solar energy, the list of efficient singlet fission sensitizers is still very short, encouraging the theoreticians to focus their efforts on selecting and designing new candidates. Here, it is presented a computational protocol for the efficient screening of databases to select those species matching the energy requirements for singlet fission. Hence, out of the initial 29,123 species, 254 molecules (0.87%) were found to match singlet fission energy conditions. The consideration of practical concerns such as availability or stability reduced the number to just 24 (0.08%), among which the aminoanthraquinone derivatives are found particularly promising. The proposed protocol correct the deficiencies of the preceding ones, reaching DFT accuracy and minimizing the risk of getting false negatives especially at the early stages of the screening. In addition, this protocol can be used in future high‐throughput investigations using datasets composed of millions of species.

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Monomer–Dimer solution equilibria of 2,4,6-trialkylnitrosobenzenes and 2,4,6-trialkylnitrosobenzene/nitrosobenzene mixtures. A study using one- and two-dimensional NMR techniques

Cited by 17 publications

References 22 publications

Dimerization of Aromatic C-Nitroso Compounds

Dimerization of Aromatic C-Nitroso Compounds

Structural investigations of C-nitrosobenzenes. Part 2.1 NMR studies of monomer–dimer equilibria including restricted nitroso group rotation in monomers

A new protocol for the identification of singlet fission sensitizers through computational screening

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