Many-body analysis and spectroscopic characterization of diazene oligomers: A theoretical study

The present study reports the many-body analysis and spectroscopic characterization of linear and cyclic diazene oligomers in gas and water solvent states. The oligomers of diazene from monomer to pentamer have been considered for the study. The spectroscopic studies such as geometrical parameters, infrared spectra, electronic absorption spectra, and natural transition orbitals (NTOs) were reported. Many-body analysis techniques have been implemented to study the interactions among the diazene oligomers. These calculations have been performed using exchange and correlation functional (B3LYP) and 6-311++G (d,p) basis set. The geometrical parameters and infrared modes of monomer diazene in the gas state are well-matched with the available experimental determinations at this level of theory. A significant change in vibrational modes of linear and cyclic diazene oligomers has been observed in the gas phase-to-water solvent state. The time-dependent density functional theory (TD-DFT) has been used to calculate the electronic absorption spectra of diazene oligomers. The Wavelength of electronic transitions, oscillator strength, and HOMO to LUMO gap has been reported. Manybody analysis shows that two-, three-, four-, and five-body energies have a remarkable contribution to the binding energy in addition to relaxation energies. All these calculations have been performed using Gaussian 16 program package.

Automated summary

The present study investigates the analysis and characterization of linear and cyclic diazene oligomers in gas and water solvent states. Spectroscopic techniques such as geometrical parameters, infrared spectra, electronic absorption spectra, and natural transition orbitals (NTOs) are used to study these oligomers. Many-body analysis techniques are implemented to examine the interactions among the diazene oligomers using B3LYP exchange and correlation functional and 6-311++G (d,p) basis set. Significant changes in vibrational modes are observed when transitioning from gas phase to water solvent phase. The electronic absorption spectra, wavelength of electronic transitions, oscillator strength, and HOMO to LUMO gap are calculated using time-dependent density functional theory (TD-DFT).