Spectres photoélectroniques de cyclohexène-2 ones-1 diversement substituées en position 3. Correlations avec la réactivité

1982 ◽  
Vol 60 (10) ◽  
pp. 1163-1172 ◽  
Author(s):  
Geneviève Pfister-Guillouzo ◽  
Serge Geribaldi ◽  
Jean-François Gal
Keyword(s):  
Linear Relationship ◽  
Ionization Potential ◽  
Methylene Chloride ◽  
Substituent Effects ◽  
Lone Pair ◽  
Carbonyl Oxygen ◽  
Ionization Potentials ◽  
Aromatic Ketones ◽  
Different Types ◽  
Oxygen Lone Pair

We have recorded the photoelectronic spectra of 32 differently 3-substituted 2-cyclohexen-1-ones as well as those of 10 para-substituted acetophenones. Assignment of most of the cyclohexenone bands is made and the substituent effects on the π-electron ionization potentials and of the oxygen lone pair are discussed. The linear relationship between the ionization potential of the carbonyl oxygen lone pair and σp-type constants as well as those between the ionization potentials and the enthalpies of complexation (ΔH0) of the ketones with BF3 in methylene chloride allows us to propose that the direct conjugative interaction between the substituents and the carbonyl group is weak in the free ketone but becomes very strong in the complexed or protonated state. The existence of two distinct relationships (ΔH0 = f(PI n0) for 3-substituted cyclohexenones and the aromatic ketones indicates that this type of expression cannot be used for the comparison of the Lewis basicities of different types of ketones; on the contrary, these expressions do allow for the comparison of the relative basicities of the same type. [Journal Translation]

Photoelectron Spectra and Molecular Properties, XLVIII Carbonates and Thiocarbonates

1975 ◽  
Vol 30 (11-12) ◽  
pp. 862-874 ◽  
Author(s):  
K. Wittel ◽  
E. E. Astrup ◽  
H. Bock ◽  
G. Graeffe ◽  
H. Juslén
Keyword(s):  
Ionization Potential ◽  
Substituent Effects ◽  
Lone Pair ◽  
Emission Spectra ◽  
Low Energy ◽  
Photoelectron Spectra ◽  
Energy Bands ◽  
Open Chain ◽  
First Ionization Potential ◽  
Cndo Calculations

Photoelectron (PE) spectra of ethylene and vinylene carbonates and thiocarbonates as well as of methylene trithiocarbonate and some open-chain derivatives are reported.The low energy bands, well separated in the unsaturated compounds, are assigned to lone pair and π type ionizations. The assignment is based on comparison of PE spectra, modified CNDO calculations, and sulfur Κβ emission spectra. The pronounced substituent effects due to which the first ionization potential varies from 8.4 eV to 11.1 eV are discussed.

Electronic Levels of Methyl Amines by Photoelectron Spectroscopy and an i.n.d.o. Calculation

1971 ◽  
Vol 49 (7) ◽  
pp. 1135-1136 ◽  
Author(s):  
A. B. Cornford ◽  
D. C. Frost ◽  
F. G. Herring ◽  
C. A. McDowell
Keyword(s):  
Binding Energy ◽  
Ionization Potential ◽  
Photoelectron Spectroscopy ◽  
Lone Pair ◽  
Ionization Potentials ◽  
The One ◽  
First Ionization Potential

The ionization potentials of the methyl amines down to 20 eV binding energy, have been determined by photoelectron spectroscopy, and are compared with those predicted by i.n.d.o.-l.c.a.o.-s.c.f. theory. The first ionization potential for each compound refers to the removal of an electron from the lone pair, and is shown to be the one most affected by the inclusion of one center repulsion integrals in the i.n.d.o. calculations.

Solid-state structure of a layered hydrogen-bonded salt: guanidinium 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonate methanol solvate

1996 ◽  
Vol 52 (1) ◽  
pp. 209-214 ◽  
Author(s):  
V. A. Russell ◽  
M. D. Ward
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Lone Pair ◽  
Carbonyl Oxygen ◽  
Two Dimensional ◽  
State Structure ◽  
Hydroxyl Proton ◽  
Intramolecular Hydrogen ◽  
Oxygen Lone Pair ◽  
Hydrogen Bonded

Guanidinium 5-benzoyl-4-hydroxy-2-methoxybenzene-sulfonate methanol solvate [C(NH2)3 +.(C14H11O3)SO3 −.CH3OH] crystallizes into a layered structure containing a two-dimensional hydrogen-bonded network typical of guanidinium alkane- and arenesulfonates. All six guanidinium protons and six sulfonate oxygen lone-pair acceptors participate in hydrogen bonding to form nearly planar pseudohexagonal hydrogen-bonded sheets, which can be viewed as parallel connected hydrogen-bonded ribbons. The 5-benzoyl-4-hydroxy-2-methoxybenzene groups are oriented to the same side of each ribbon, but the orientation of these groups on adjacent ribbons alternates with respect to the hydrogen-bonded sheet. The planar sheets stack with interdigitation of the arene groups, resulting in a structure in which layers of 5-benzoyl-4-hydroxy-2-methoxybenzene groups are separated by ionic hydrogen-bonded sheets. Each methanol molecule forms a hydrogen bond to one of the sulfonate O atoms, resulting in this oxygen forming a total of three hydrogen bonds, and fills void volume between the interdigitated 5-benzoyl-4-hydroxy-2-methoxybenzene groups of neighboring sheets. The benzophenone hydroxyl proton forms an intramolecular hydrogen bond to the carbonyl oxygen.

Photoelectron spectra of substituted oxiranes and thiiranes. Substituent effects on ionization potentials involving σ orbitals

1977 ◽  
Vol 55 (2) ◽  
pp. 318-332 ◽  
Author(s):  
E. J. McAlduff ◽  
K. N. Houk
Keyword(s):  
Ionization Potential ◽  
Substituent Effects ◽  
Great Sensitivity ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Ethyl Vinyl ◽  
Alkyl Groups ◽  
Koopmans Theorem ◽  
Opposite Order ◽  
The Subject

The state assignments corresponding to the second and third ionization potentials of oxirane have been the subject of some uncertainty due to the great sensitivity of Koopmans' theorem predictions to the type of calculation performed for this molecule. In this study, the assignments made by Basch et al. for oxirane are confirmed through measurement of the photoelectron spectra of methyl-, 1,1-dimethyl-, 1,2-dimethyl, ethyl-, vinyl-, phenyl-, chloromethyl-, and fluoromethyloxirane. The second and third ionizations of thiirane are confirmed to be of the opposite order from those in oxirane by correlations of these values with those reported here for methyl-, vinyl, and methoxymethylthiirane.In these compounds, mono-substitution by alkyl groups causes a decrease in ionization potential not obviously related in a simple way to the type of orbital involved. Thus, assignments cannot be made straightforwardly by observing ionization potential changes caused by hyper-conjugating or inductive substituents. Alkyl group substitution in both oxirane and thiirane lowers IP's in the same order: a2 > b2 > a1 > b1. The effects of alkyl and heteroalkyl groups on the four lowest IP's of oxirane are linearly related to the electronegativities of the groups, and to the influence of alkyl and heteroalkyl substituents on the π IP of ethylene.Comparisons of the IP's of ethylheteranes and dimethylheteranes are quite useful in determining the site of localization of orbital density in the various orbitals.Conjugating substituents, which for symmetry reasons, selectively interact with only a few orbitals make definite assignments possible. Comparisons of experimental ionization potential changes and those predicted by Koopmans' theorem using ab initio STO-3G calculations are in good agreement.

Bond-length distributions for ions bonded to oxygen: Metalloids and post-transition metals

2017 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Metal Ions ◽  
Bond Length ◽  
Lone Pair ◽  
Transition Metal Ions ◽  
Oxygen Lone Pair

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.

Bond-length distributions for ions bonded to oxygen: Metalloids and post-transition metals

2017 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Metal Ions ◽  
Bond Length ◽  
Lone Pair ◽  
Transition Metal Ions ◽  
Oxygen Lone Pair

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.

Bond-length distributions for ions bonded to oxygen: Results for the non-metals and discussion of lone-pair stereoactivity and the polymerization of PO4

2017 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Metal Ions ◽  
Bond Length ◽  
Lone Pair ◽  
Group 14 ◽  
Oxygen Lone Pair

Bond-length distributions are examined for three configurations of the H+ ion, sixteen configurations of the group 14-16 non-metal ions and seven configurations of the group 17 ions bonded to oxygen. Lone-pair stereoactivity for ions bonded to O<sup>2-</sup> is discussed, as well as the polymerization of the PO<sub>4</sub> group.

scholarly journals Long-term stability in γ-CsPbI3 perovskite via an ultraviolet-curable polymer network

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Nam-Kwang Cho ◽  
Hyun-Jae Na ◽  
Jeeyoung Yoo ◽  
Youn Sang Kim
Keyword(s):  
Polymer Network ◽  
Lone Pair ◽  
Ambient Conditions ◽  
Absorption Properties ◽  
Term Stability ◽  
Long Term Stability ◽  
Ultraviolet Curable ◽  
Oxygen Lone Pair ◽  
Lone Pair Electrons

AbstractBlack-colored (α, γ-phase) CsPbI3 perovskites have a small bandgap and excellent absorption properties in the visible light regime, making them attractive for solar cells. However, their long-term stability in ambient conditions is limited. Here, we demonstrate a strategy to improve structural and electrical long-term stability in γ-CsPbI3 by the use of an ultraviolet-curable polyethylene glycol dimethacrylate (PEGDMA) polymer network. Oxygen lone pair electrons from the PEGDMA are found to capture Cs+ and Pb2+ cations, improving crystal growth of γ-CsPbI3 around PEGDMA. In addition, the PEGDMA polymer network strongly contributes to maintaining the black phase of γ-CsPbI3 for more than 35 days in air, and an optimized perovskite film retained ~90% of its initial electrical properties under red, green, and blue light irradiation.

ChemInform Abstract: A THEORETICAL EVALUATION OF SUBSTITUENT EFFECTS ON THE IONIZATION POTENTIAL OF BICYCLO(1.1.0)BUTANE

1985 ◽  
Vol 16 (25) ◽  
Author(s):  
S. C. RICHTSMEIER ◽  
P. G. GASSMAN ◽  
D. A. DIXON
Keyword(s):  
Ionization Potential ◽  
Substituent Effects ◽  
Theoretical Evaluation
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