Experimental Evidence of Sensitivity of the High Harmonic Generation to Hydrogen Bonding

Abstract

The influence of hydrogen bonding and the associated attosecond hole delocalization on the high-order harmonic generation (HHG) process is investigated with the help of hydrogen-bonded binary mixture of acetonitrile and chloroform solvent vapors. We observe a strong enhancement of the HH yield compared to the results obtained with pure samples. We propose that the observed increase of HHG efficiency is due to the presence of hydrogen-bonded binary mixture. Numerical simulations show evidence of the attosecond hole delocalization in the hydrogen-bonded complex of acetonitrile and chloroform. This attosecond hole delocalization contributes to the enhancement of the harmonic yield in the hydrogen-bonded complex. To the best of our knowledge, this is the first report on the sensitivity of the high harmonic generation process to the hydrogen bonding.

On the Analysis of High Harmonic Generation Spectra of Atoms and Molecules Using Molecular Electrostatic Potential

“…Finally, the harmonic spectrum is obtained by taking the modulus square of the Fourier transform of the dipole acceleration (eq ). These procedures are already discussed in our and Dixit’s earlier works. , …”

“…These procedures are already discussed in our and Dixit's earlier works. 18,19 We choose a laser pulse with a center frequency of 0.056 a.u. (wavelength is 800 nm), intensity of 2.2 × 10 14 W/cm 2 , and 22 cycles in the sin 2 envelope for the simulation of the HHG spectra of the He + ion and neutral He, Ar, and Kr atoms.…”

Charge Migration in Heterocyclic Five-Membered Rings

“…We believe that our results on attosecond charge migration in heterocyclic five-membered rings will motivate further theoretical investigations in other types of molecular systems, where studies of structure-dynamics relationships are still few and far apart. Further, state-of-theart emerging experimental techniques, such as attosecond transient absorption spectroscopy [10,11], high-harmonic generation spectroscopy [9,12,60,61], or time-resolved x-ray diffraction [62,63], to name but a few, will provide potent probes for our findings in heterocyclic five-membered ring molecules in the coming future.…”