Photoreactions of the CH-SO Complex in a Low-Temperature Matrix Investigated by Infrared Spectroscopy and Density Functional Theory Calculations.

Ethylene and sulfur dioxide molecules were co-deposited on a CsI window at cryogenic temperature, and the photoproducts upon UV irradiation were observed using Fourier transform infrared (FTIR) spectroscopy. The products were found to be UV wavelength-dependent; at shorter wavelengths (λ = 266 nm) one strong peak was observed while more than three peaks were identified at longer UV wavelengths (λ = 300 nm). Spectral features changed seamlessly along with UV wavelength.

Proton Chelating Ligands Drive Improved Chemical Separations for Rhodium.

Current methods for the extraction of rhodium carry the highest carbon footprint and worst pollution metrics of all of the elements used in modern technological applications. Improving upon existing methods is made difficult by the limited understanding of the molecular-level chemistry occurring in extraction processes, particularly in the hydrometallurgical separation step. While many of the precious metals can be separated by solvent extraction, there currently exist no commercial extractants for Rh.

Matrix-isolation infrared studies of 1:1 molecular complexes containing chloroform (CHCl3) and Lewis bases: seamless transition from blue-shifted to red-shifted hydrogen bonds.

The infrared spectra of molecular complexes containing chloroform (CHCl(3)) and Lewis bases (N(2), CO, H(2)O, and CH(3)CN) have been observed in an Ar matrix, and vibrational peaks for the 1:1 complexes have been assigned. The C-H stretching band of chloroform in the complexes showed a seamless transition from a blue shift (for N(2) and CO) to a red shift (H(2)O and CH(3)CN), in accord with the proton affinity of the base molecules. Density functional calculations predicted that the C-H··(σ-type lone pair) isomer is the most stable, which is consistent with the observed vibrational peak shift upon complex formation.

Modeling and spectral simulation of matrix-isolated molecules by density functional calculations: a case study on formic acid dimer.

The supermolecule approach has been used to model molecules embedded in solid argon matrix, wherein interaction between the guest and the host atoms in the first solvation shell is evaluated with the use of density functional calculations. Structural stability and simulated spectra have been obtained for formic acid dimer (FAD)-Ar(n) (n = 21-26) clusters. The calculations at the B971∕6-31++G(3df,3pd) level have shown that the tetrasubstitutional site on Ar(111) plane is likely to incorporate FAD most stably, in view of consistency with the matrix shifts available experimentally.

Torsion-rotation coupling and the determination of the torsional potential energy function of HSOH.

Hindered torsional motion in a molecule such as HSOH leads to tunnelling splittings. Lying between the simpler limiting cases of strongly hindered torsion (the "we can simply neglect the tunnelling" limit) and that of free internal rotation (the "tunnelling pair of levels are just different vibrational states" limit) HSOH is particularly challenging due to strong and inherent torsion-rotation coupling. The low symmetry due to the different terminal moieties, SH and OH, further enriches the energy level pattern by allowing a systematic mixing within each quadruplet of torsion- and asymmetry-doubled levels.

Infrared spectra of (HCOOH)(2) and (DCOOH)(2) in rare gas matrices: a comparative study with gas phase spectra.

Infrared absorption spectra of (HCOOH)(2) and (DCOOH)(2) in solid argon, krypton, and xenon matrices have been measured and each fundamental band has been assigned. Spectra in Ar and Kr matrices showed notable splitting in contrast to those in Xe, which suggests a difference in structure of the trapping sites. A comparison with the reported jet-cooled spectra has shown that vibrational structures of the spectra of (HCOOH)(2) and (DCOOH)(2) in the O-H stretching region are preserved in the matrices.

Infrared spectra of the (H2O)n-SO2 complexes in argon matrices.

The infrared spectra of the (H(2)O)n-SO(2) complexes trapped in argon matrices have been investigated using Fourier transform infrared spectroscopy. In addition to the 1:1 and 2:1 complexes, the first spectroscopic evidence for the 3:1 complex has been obtained from the spectra of the SO stretching and the OH stretching modes. The observed frequency shifts in the bonded OH stretching region indicate that the hydrogen bonds of the 2:1 and 3:1 complexes are strengthened compared to that of the 1:1 complex, which suggests the cyclic structure of the complexes.

Infrared spectra of the CF3I dimer: a concurrent application of matrix-isolation spectroscopy and cavity ring-down spectroscopy.

We have observed infrared spectra of the CF(3)I dimer produced in a supersonic jet by matrix-isolation Fourier transform infrared spectroscopy and infrared cavity ring-down (IR-CRD) spectroscopy. In the matrix-isolation experiments, the dimer was isolated in an Ar matrix by the pulse-deposition method. The recorded spectral range covers the symmetric (nu(1)) and doubly degenerate (nu(4)) C-F stretching regions.

Methyl iodide clusters observed in gas phase by infrared cavity ring-down spectroscopy: the CH3 bending mode at 8 microm.

Infrared spectra of methyl iodide clusters produced in a supersonic jet have been observed in the CH3 bending region at 8 mum by cavity ring-down spectroscopy. The dependence of the spectral features on the mixing ratio of CH3I to He and on the stagnation pressure has allowed us to assign the absorption peaks, with the help of the previous results obtained by matrix-isolation technique [Ito et al., Chem.

Coherent phase control of the product branching ratio in the photodissociation of dimethylsulfide.

Coherent phase control of the photodissociation reaction of the dimethylsulfide has been achieved by means of quantum-mechanical interference between one- and three-photon transitions. Dimethylsulfide was irradiated by fundamental and frequency-tripled outputs of a visible laser (600.5-602.