The electronic absorption spectra of some N-sulfinylanilines. A molecular orbital treatment

Abstract

The electronic absorption spectra of N-sulfinylaniline and some of its derivatives were investigated using different solvents. The spectral behavior of the molecules indicated their planarity and that the NSO group is a strong electron acceptor. All the observed bands correspond to delocalized π → π* transitions; n → π* transition were not observed as discrete bands. Ab initio molecular orbital calculations were performed using four different basis sets. The results showed that the NSO group is nonlinear, the molecules studied are planar, and the syn conformer is more stable than the anti conformer. Keywords: N-sulfinylanilines, spectra and theoretical treatment.

Stimuli-Responsive Luminescent Solar Concentrators Based on Photoreversible Polymeric Systems

“…UV–vis absorption spectrum (Figure B) of PU-Cou coated on quartz displayed a broad, intense signal around 320 nm, which is characteristic of substituted coumarins and related to overlapping π–π* electron transitions of conjugated benzene and pyrone chromophores . Moreover, the fluorescence emission spectrum, with 320 nm as the excitation wavelength, exhibited a broad band peaking at λ = 394 nm (blue curve), which is typical of coumarin derivatives bearing electron-donating groups at position 7, as the precursor HEOMC …”

From Inert to Explosive, The Hydrolytic Reactivity of R−NSO Compounds Understood: A Computational Study

“…These are the most extensively studied N-sulfinyl species. X-ray diffraction, infrared and Raman, ultraviolet, microwave, and nuclear magnetic resonance spectroscopic techniques, − ,− ,,− as well as various theoretical model chemistries ,,,, have been employed for the determination of their structural characteristics. Geometric parameters and substituent effects on the activation enthalpy for the hydrolysis of N-sulfinylamines with R = H, Me, Ph, and CF 3 have been discussed in detail in our previous paper in comparison to the corresponding substituted isocyanates .…”

“…The order of saddle points was determined through vibrational frequency calculations. Despite the possibility of configurational isomers for N-sulfinyl compounds, only the most energetically favorable syn configuration − ,,,,,,,,− is considered here. The intrinsic reaction coordinate (IRC) procedure , was applied to selected transition states to verify the nature of the potential energy surface for a proposed reaction path.…”

High‐Efficiency Luminescent Solar Concentrators Based on Antifogging and Frost‐Resisting Fluorescent Polymers: Adding Multiple Functions for Sustained Performance

“…As expected, QP‐CMA0 did not absorb in the UV region, while QP‐CMA1 and QP‐CMA5 displayed an intense signal centered at 320 nm, which is characteristic of substituted coumarins and related to overlapping π–π* electron transitions of conjugated benzene and pyrone chromophores. [ 39 ] In particular, the absorption intensity was found to proportionally increase with the CMA feed molar content, further indicating the complete incorporation of coumarin during the synthetic step. Moreover, the fluorescence emission spectrum, recorded with λ exc = 320 nm, exhibited a broad band peaking at λ = 394 nm, which is typical of coumarin derivatives bearing electron‐donating groups at position 7, as in the case of the CMA precursor used for the preparation of this monomer (7‐(hydroxy ethoxy)‐4‐methylcoumarin [HEOMC], see the Experimental Section).…”