According to the interlacing rule, if A and Bτ are two molecules which differ by a single isotopic substitution at atomic site τ, vibrational frequencies of a molecule A are interlaced with the vibrational frequencies of molecule Bτ. This rule is valid within the harmonic approximation, and in the case of planar molecules one has two interlacing rules, one for in-plane and another for out-of-pl...

We are presenting the electronic photofragment spectra of the protonated pyrimidine DNA base homodimers. Only the thymine dimer exhibits a well structured vibrational progression, while the protonated monomer shows broad vibrational bands. This shows that proton bonding can block some nonradiative processes present in the monomer.

We predict an anomaly in highly excited bending spectra of acetylene with high vibrational angular momentum. We interpret this in terms of a vibrational shape effect with moment of inertia backbending, induced by a sequence of bifurcations with a transition from "local" to "orthogonal" modes.

The application of femtosecond pump-probe photoelectron spectroscopy to directly observe vibrational wave packets passing through an avoided crossing is investigated using quantum wave packet dynamics calculations. Transfer of the vibrational wave packet between diabatic electronic surfaces, bifurcation of the wave packet, and wave packet construction via nonadiabatic mixing are shown to be obs...

In the present work, we reported a combined experimental and theoretical study on molecular structure and vibrational analysis of N-phenylethanolamine (NPEA). FT-IR and FT-Raman spectra of the title compound in the solid phase are recorded in the region 4000–400 cm and 3500–100 cm, respectively. The structural and spectroscopic data of the molecule in the ground state is calculated using densit...

The first surface vibrational sum frequency generation (SFG) spectroscopic studies of amine-terminated Starburst® PAMAM G0 and G1 and acylated PAMAM G0 dendrimers at the glass–, gold–, and air–dendrimer interface are presented. Amine-terminated PAMAM G0 and G1 dendrimers as compared to the acylated PAMAM G0 dendrimer reveal significantly different surface SFG spectroscopic signatures. Raman spe...

Metformin is one of the important anti-diabetic drugs to treat non-insulin dependent diabetes mellitus (NIDDM). Fourier transform infrared (FTIR) and Fourier transform Raman (FTR) spectra of metformin have been used for the molecular study. A satisfactory band assignment has been made on the fundamental modes of vibration. Employing the molecular mechanics method using MM3 force field, the theo...

A homogeneous graph is a graph together with a group which acts transitively on vertices as symmetries of the graph. We consider Laplacians of homogeneous graphs and generalizations of Laplacians whose eigenvalues can be associated with various equilibria of forces in molecules (such as vibrational modes of buckyballs). Methods are given for calculating such eigenvalues by combining concepts an...

High-resolution anion photoelectron spectra are reported for the group 4 metal dioxide clusters Ti2O4(-) and Zr2O4(-). Slow photoelectron velocity-map imaging (SEVI) spectroscopy of cryogenically cooled, mass-selected anions yields photoelectron spectra with submillielectronvolt resolution, revealing extensive and well-resolved vibrational progressions. By comparison of the spectra with Franck-...

The infrared vibrational absorption (VA) and vibrational circular dichroism (VCD) spectra of methyl lactate in carbon tetrachloride and methanol have been measured in the 1000-1800 cm region. Noticeable changes due to the solute self-aggregation and solvent-solute intermolecular hydrogen-bonding in the reported spectra have been detected. A series of density functional theory (DFT/B3LYP/6-311++...