Structural determination and population transfer of 4-nitroanisole by broadband microwave spectroscopy and tailored microwave pulses

Abstract

The rotational spectrum of 4-nitroanisole was recorded via chirped-pulse Fourier transform microwave spectroscopy in the frequency range of 2-8 GHz. The spectra of the parent molecule and all of its C-,N-, and O-monosubstituted species in their natural abundance were assigned, and the molecular structure was determined using Kraitchman's equations as well as a least-square fitting approach. 4-nitroanisole has a large dipole moment of 6.15 D along the inertial a-axis and a smaller dipole moment of 0.78 D along the b-axis. The large dipole moment component makes this molecule a potential candidate for deceleration experiments using static electric fields or electromagnetic radiation. Using tailored microwave pulses, we investigate the possibility of transferring population between the rotational states of 4-nitroanisole. Such a technique could be applied to selectively increase the population for specific rotational states of interest, which are then accessible for further, more advanced experiments, such as deceleration.

Dipole moments of conjugated donor–acceptor substituted systems: calculations vs. experiments

“…Indeed, the calculated using B3LYP/aug-cc-pVTZ basis set with anharmonic correction(provided Sz for the C–OMe bond 1.356 and for the C–NO 2 bond of 1.472 Å in agreement with the experimental r m 1.356(2) and 1.475(3) Å. 54 The calculated μ zGS was 6.139 D. The experimental DM value of 5.22 D 55 was determined at 470 K, far above the T c . The calculated μ avg and μ 3S ( Table 4 ) reproduce this value well.…”

“…The structure of 10 was determined from the MW spectra at 1 K, but no experimental DM was provided. 54 The calculated using the three-state approach barriers to rotation Δ G ≠ 298 of 10 are 6.94 (–NO 2 ) and 4.18 (CH 3 O–) kcal mol −1 corresponding roughly to T c between 100 and 120 K and, therefore, at 1 K the geometry of molecule should be close to the equilibrium. Indeed, the calculated using B3LYP/aug-cc-pVTZ basis set with anharmonic correction(provided Sz for the C–OMe bond 1.356 and for the C–NO 2 bond of 1.472 Å in agreement with the experimental r m 1.356(2) and 1.475(3) Å.…”

Investigation of robust population transfer using quadratically chirped laser interacting with a two-level system

“…In the quadratic chirped method, the adiabatic condition is obtained as: (2 ) t    (5) In this regard, by decreasing the chirping parameter and the transition time or by increasing the coupling strength the adiabatic condition can be satisfied. It should be also noted that in this relation, the transition time depends on the chirping parameter so that by increasing the chirping parameter, the transition time is reduced.…”

“…Manipulation and control of quantum states are substantial issues in various fields of atomic physics including quantum information [1][2][3], atomic clocks [4], spectroscopy [5], surface plasmon polariton [6,7], chemical reactions [8], Bose-Einstein condensate [9], collision dynamics [10], laser cooling [11], interferometry [12], and magnetic resonance [13]. Among these applications, much attention is focused on keeping these quantum systems at high fidelity and robustness [14][15][16].…”

Robust population transfer in a two-level system using finite chirping method

“…Many different atomic physic and chemistry experiments are engaged with the population transfer between two-level or multi-level quantum systems including atomic and molecular spectroscopy [1,2], atomic clocks [3,4], interferometry [5], magnetic resonance [6], quantum information processing [7][8][9], chemical reactions [10,11], collision dynamics [12] and laser cooling [13]. Because of that, the population transfer plays a significant role in quantum engineering and working towards developing robust and efficient transferring techniques has been always an attractive research field.…”