ChemInform Abstract: Interactions Between Oxygen Lone-Pair Orbitals and Double-Bond π-Orbitals in β,γ-Unsaturated, Bicyclic Ketones: A PE-Spectroscopic Investigation

ChemInform ◽  
1987 ◽  
Vol 18 (50) ◽  
Author(s):  
P.-A. CARRUPT ◽  
R. GABIOUD ◽  
A. RUBELLO ◽  
P. VOGEL ◽  
E. HONEGGER ◽  
...  
Keyword(s):  
Double Bond ◽  
Spectroscopic Investigation ◽  
Lone Pair ◽  
Bicyclic Ketones ◽  
Oxygen Lone Pair

Interactions between Oxygen Lone-Pair Orbitals and Double-Bond ?-Orbitals in ?,?-Unsaturated, Bicyclic Ketones; a PE-Spectroscopic Investigation

1987 ◽  
Vol 70 (6) ◽  
pp. 1540-1550 ◽  
Author(s):  
Pierre-Alain Carrupt ◽  
Raphy Gabioud ◽  
Albino Rubello ◽  
Pierre Vogel ◽  
Evi Honegger ◽  
...  
Keyword(s):  
Double Bond ◽  
Spectroscopic Investigation ◽  
Lone Pair ◽  
Bicyclic Ketones ◽  
Oxygen Lone Pair

Photoelectron Spectroscopy of Heterocycles. Phenyloxiranes

1984 ◽  
Vol 39 (12) ◽  
pp. 1230-1234 ◽  
Author(s):  
H. Güsten ◽  
L. Klasinc ◽  
I. Novak ◽  
M. Sanjek
Keyword(s):  
Double Bond ◽  
Ethylene Oxide ◽  
Photoelectron Spectroscopy ◽  
Lone Pair ◽  
Photoelectron Spectra ◽  
Ionization Energies ◽  
Perpendicular Orientation ◽  
Trans Stilbene ◽  
Oxygen Lone Pair

The Hel photoelectron spectra of 2-phenyloxirane, 2,2-diphenyloxirane, trans-2.3-diphenyloxirane, 2,2,3-triphenyloxirane, and 2,2,3,3-tetraphenyloxirane are reported. Comparison with the spectra of ethylene oxide (oxirane), benzene, and the following phenylethenes-styrene (1). I,1-diphenylethene (2), cis-stilbene (3), trans-stilbene (4), triphenylethene (5), and tetraphenylethene (6) - allowed to assign the lower ionization energies of the phenyloxiranes. Splitting of the lowest energy benzene π-orbitals is qualitatively the same in both classes of compounds. Because of the perpendicular orientation of the oxygen lone-pair in comparison to the π-electrons of the ethylene double bond this splitting is considerably smaller in phenyloxiranes.

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.

scholarly journals Unsaturated and Benzannulated N-Heterocyclic Carbene Complexes of Titanium and Hafnium: Impact on Catalysts Structure and Performance in Copolymerization of Cyclohexene Oxide with CO2

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4364
Author(s):  
Lakshmi Suresh ◽  
Ralte Lalrempuia ◽  
Jonas B. Ekeli ◽  
Francis Gillis-D’Hamers ◽  
Karl W. Törnroos ◽  
...  
Keyword(s):  
Density Functional ◽  
Lone Pair ◽  
Catalytic Performance ◽  
Nbo Analysis ◽  
Cyclohexene Oxide ◽  
Group 4 ◽  
Low Co2 ◽  
And Performance ◽  
High Yields ◽  
Oxygen Lone Pair

Tridentate, bis-phenolate N-heterocyclic carbenes (NHCs) are among the ligands giving the most selective and active group 4-based catalysts for the copolymerization of cyclohexene oxide (CHO) with CO2. In particular, ligands based on imidazolidin-2-ylidene (saturated NHC) moieties have given catalysts which exclusively form polycarbonate in moderate-to-high yields even under low CO2 pressure and at low copolymerization temperatures. Here, to evaluate the influence of the NHC moiety on the molecular structure of the catalyst and its performance in copolymerization, we extend this chemistry by synthesizing and characterizing titanium complexes bearing tridentate bis-phenolate imidazol-2-ylidene (unsaturated NHC) and benzimidazol-2-ylidene (benzannulated NHC) ligands. The electronic properties of the ligands and the nature of their bonds to titanium are studied using density functional theory (DFT) and natural bond orbital (NBO) analysis. The metal–NHC bond distances and bond strengths are governed by ligand-to-metal σ- and π-donation, whereas back-donation directly from the metal to the NHC ligand seems to be less important. The NHC π-acceptor orbitals are still involved in bonding, as they interact with THF and isopropoxide oxygen lone-pair donor orbitals. The new complexes are, when combined with [PPN]Cl co-catalyst, selective in polycarbonate formation. The highest activity, albeit lower than that of the previously reported Ti catalysts based on saturated NHC, was obtained with the benzannulated NHC-Ti catalyst. Attempts to synthesize unsaturated and benzannulated NHC analogues based on Hf invariably led, as in earlier work with Zr, to a mixture of products that include zwitterionic and homoleptic complexes. However, the benzannulated NHC-Hf complexes were obtained as the major products, allowing for isolation. Although these complexes selectively form polycarbonate, their catalytic performance is inferior to that of analogues based on saturated NHC.

Charge density distribution and theoretical analysis of low and high energy phosphate esters

RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 96623-96638 ◽  
Author(s):  
Adrian Mermer ◽  
Tadeusz Lis ◽  
Przemysław Starynowicz
Keyword(s):  
Density Distribution ◽  
Charge Density ◽  
Lone Pair ◽  
High Energy ◽  
Phosphate Esters ◽  
High Energy Phosphate ◽  
Charge Density Distribution ◽  
Oxygen Lone Pair ◽  
Hydrolysis Of ◽  
Experimental Charge Density

There is a strict relation between the energy of hydrolysis of phosphate esters and the extent of interactions between the p ester oxygen lone pair and the antibonding orbitals of the rest of the molecule. Its impact on experimental charge density distribution is analyzed.

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