IR spectra, dipole moments, and conformations of bis(dichloroarsino)methane

1989 ◽  
Vol 29 (5) ◽  
pp. 701-706
Author(s):  
A. B. Remizov ◽  
F. G. Khalitov ◽  
F. G. Garieva
Keyword(s):  
Ir Spectra ◽  
Dipole Moments

Synthesis, separation, and identification of 4-bromoadamantan-2-one stereoisomers

1980 ◽  
Vol 45 (10) ◽  
pp. 2670-2674 ◽  
Author(s):  
Luděk Vodička ◽  
Jan Tříska ◽  
Milan Hájek
Keyword(s):  
Ir Spectra ◽  
Hydrobromic Acid ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Dipole Moments ◽  
Hydroxylamine Hydrochloride ◽  
Shift Reagent ◽  
One Step ◽  
Elution Chromatography ◽  
The Eu

A one-step synthesis of mixture of stereoisomers of 4-bromoadamantan-2-one based on the reaction of adamantan-2-one with hydroxylamine hydrochloride in hydrobromic acid is described. The pure stereoisomers were isolated by elution chromatography on silica gel, and their NMR spectra with the Eu(FOD)3 shift reagent, mass spectra, IR spectra, and dipole moments were measured.

scholarly journals Molecular structure of calcium, magnesium, strontium and barium m-nitrobenzoates

2010 ◽  
Vol 24 (3-4) ◽  
pp. 433-437 ◽  
Author(s):  
Mariola Samsonowicz
Keyword(s):  
Molecular Structure ◽  
Electronic Structure ◽  
Ir Spectra ◽  
Dipole Moments ◽  
Atomic Charges ◽  
Barium Ions ◽  
Nitrobenzoic Acid ◽  
Calcium Magnesium ◽  
Ft Ir

The effect of calcium, magnesium, strontium and barium ions on the electronic structure of m-nitrobenzoates was studied. The FT-IR spectra of m-nitrobenzoic acid and its salts were registered, assigned and analyzed. Characteristic shifts and changes in intensities of bands along the metal series were observed. The structures of m-nitrobenzoic acid and its calcium, magnesium, strontium and barium salts were optimized at the B3LYP/LANL2DZ level. Geometric aromaticity indices, atomic charges, dipole moments and energies were also calculated.

Gas-phase spectroscopic characterization of neutral and ionic polycyclic aromatic phosphorus heterocycles (PAPHs)

2020 ◽  
Vol 500 (2) ◽  
pp. 2564-2576
Author(s):  
Ricardo R Oliveira ◽  
Germán Molpeceres ◽  
Felipe Fantuzzi ◽  
Heidy M Quitián-Lara ◽  
Heloisa M Boechat-Roberty ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Density Functional ◽  
Dipole Moments ◽  
Closed Shell ◽  
Spectroscopic Characterization ◽  
Infrared Emission ◽  
Proton Affinities ◽  
Anionic Species ◽  
Polycyclic Aromatic ◽  
Phosphorus Heterocycles

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) constitute an essential family of compounds in interstellar (ISM) and circumstellar (CSM) media. Recently, formation routes for the corresponding polycyclic aromatic phosphorus heterocycles (PAPHs) in astrophysical environments have been proposed. In order to contribute to a better understanding of the phosphorus chemistry in the ISM, infrared (IR) spectra and selected properties of PAPHs were computed at the density functional theory level for neutral, cationic, and anionic species. Our results reveal that several protonated PAPHs do not have planar backbones, and all species have permanent dipole moments between 2D and 4D. Closed-shell PAPHs have similar ionization potentials compared to the parent PAHs, below the Lyman threshold limit. In addition, all PAPHs show positive electron affinities higher than those of PAHs. Protonation preferably occurs on the heteroatom but with lower proton affinities than those of the corresponding nitrogen analogues (polycyclic aromatic nitrogen heterocycles). In general, neutral species have similar IR spectra profile with the most intense bands around 800 cm−1 (12.5 μm) related to C−H wagging. Charge and protonation affect the IR spectra mainly by decreasing the intensities of these modes and increasing the ones between 1000 (10.0 μm) and 1800 cm−1 (5.6 μm). The P−H stretching appears in a different spectral region, between 2300 (4.3 μm) and 2700 cm−1 (3.7 μm). Our results are discussed in the context of distinct sources where PAHs and phosphorus are detected. PAPHs, in particular the coronene derivatives, can contribute to the unidentified infrared emission band at 6.2 μm.

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