Absorption Spectra Of Acetone Research Articles

Spectral Shift of the n → π* Transition for Acetone and Formic Acid with an Explicit Solvent Model

In our recent work, a new form of the electrostatic solvation energy for the nonequilibrium polarization has been derived by introducing the method of constrained equilibrium state in the framework of continuous medium theory. Up until now, the idea of the constrained equilibrium state method has not been introduced into the explicit solvent model by others; therefore this nonequilibrium energy form was further equivalently extended to the explicit solvent model in this work based on the discrete representation of the solvent permanent charges and induced dipoles. Making use of this expression in explicit solvent model, we modified the nonequilibrium module in the averaged solvent electrostatic potential/molecular dynamics program to implement numerical calculations. Subsequently, the new codes were applied to study the solvatochromic shifts of the n → π* absorption spectra for acetone and trans-formic acid in aqueous solution. The calculation results show a good agreement with the experimental observations. When our results of spectral shift are compared with those achieved directly from the continuum model, it can be seen that both the explicit solvent model and continuum model derived based on the constrained equilibrium approach can give reasonable predictions. The hydrogen bond effect was also discussed and deemed to be a dominant contribution to the spectral shift by calculating the n → π* absorption spectra of acetone-water complexes.

On interaction of 193 nm excimer laser with acetone (3s Rydberg state)

The absorption spectrum of acetone in the 3s Rydberg state have been measured and assigned. The vibrational spectrum of the ground electronic X state of acetone gas was detected at different pressures. The absorption vibrational spectrum of acetone and its fragments after 193 nm photolysis were recorded using FTIR spectrometer. The time-resolved Fourier-transformed IR emission spectrometer has been used to measure the emitted spectrum of the CO molecule resulting from the photolysis of acetone by 193 nm excimer laser (4.2 MW cm −2) at a time delay of 10 μs between the laser and TR-FTIR measurement.

Van der Waals broadening of the X̃→B̃ (3s Rydberg) transition of acetone by He, Ar, and CH4: Inversion of the spectra to the interaction pair potentials

The X̃→B̃ absorption spectrum of acetone at 1944 Å, corresponding to the transition to the (n0,3s) Rydberg state, has been measured in the presence of moderate pressures of the perturbers Ar, CH4, and He. The line shape changes, which are ascribed to van der Waals perturbations, are analyzed globally using an iterative Fourier transform technique. This method is successful in inverting the distorted spectra into Lennard-Jones (6-12) potentials for the ground and excited acetone–perturber van der Waals complexes (for Ar and CH4), and into a (6-12) potential for the ground state and a repulsive potential for the excited state of the acetone–He complex. For Ar and CH4, optimized ground state (6-12) parameters are consistent with those obtained with simple combining rules; in these cases, the excited state parameters show that the interaction distance is larger than that for the ground state by ∼0.37 and 0.35 Å, respectively, and that the well depth is smaller by ∼42 and 33 cm−1, respectively. The results with He indicate that a repulsive potential is needed to describe the excited state–perturber interaction.

Solvent Effects on the Intensities of Forbidden Bands of Molecules. Absorption Spectra of Acetone and Cyclopentanone

Abstract The near ultraviolet absorption spectra of acetone and cyclopentanone have been studied in various fluid solutions at room temperature. The intensity enhancements observed are ascribed to perturbation of dispersion forces between solute and solvent molecules. The results are parallel to those of the Ham effect in benzene. No correlation was found between the intensity increments and solvent polarities. This is at variance with the correlation that has been reported in the S1(Lb)–S0 transition spectra of pyrene and coronene.

Spectral band shapes and absorption coefficients for electronic transitions

The spectral band shapes of electronic transitions corresponding to the case in which the Franck-Condon principle holds and the case in which the electronic transitions are symmetry-forbidden but vibronic-allowed have been investigated. Semiempirical equations for calculating the absorption coefficients of these two cases have been derived. In order to test this theory and demonstrate its application, the absorption spectra of acetone and cis-stilbene have been calculated and compared with the corresponding experimental spectra. Agreement is satisfactory.

Absorption of Acyclic Oxygen Compounds in the Vacuum Ultraviolet. III. Acetone and Acetaldehyde

A fluorite prism vacuum spectrograph and hydrogen lamp have been used to determine the 49 000- to 67 000-cm—1 absorption spectra of acetone and acetaldehyde in the vapor phase at 22°C.

The Absorption Spectrum of Acetone Vapor in the Far Ultraviolet

The absorption spectrum of acetone has been photographed down to 850A. Discrete bands were found above 1300A but only continuous absorption between 1300 and 850A. The bands are described and a qualitative interpretation is given of the complete spectrum. One Rydberg series was found, converging to an ionization potential of 10.20 volts.