Spectroscopy and dynamics of the dipole-bound state of acetaldehyde enolate

Abstract

Molecular rotation and the observation of dipolebound states of anions J. Chem. Phys. 99, 7586 (1993); 10.1063/1.465688 Spectroscopy and dynamics of the dipolesupported state of acetyl fluoride enolate anion J. Chem. Phys. 88, 6785 (1988); 10.1063/1.454424Threshold resonances in the electron photodetachment spectrum of acetaldehyde enolate anion. Evidence for a lowlying, dipolesupported state Ultrahigh-resolution photodetachment spectroscopy of acetaldehyde enolate negative ion has revealed -50 narrow resonances near threshold, corresponding to excitation to a diffuse state in which the electron is weakly bound by the field of the molecular dipole. A complete analysis of rotational transitions between the ground valence state and the excited dipole-bound state has been carried out, yielding spectroscopic constants and geometries for both states. In analogy to Rydberg states, the structure of the "neutral core" of the dipole-bound state is like that of the neutral radical. The dependence of autodetachment lifetimes upon the rotational quantum numbers of the dipole-bound state has been measured. Bound levels of the dipole-bound anion state are readily electric-field detached. The selection rules and dynamics of autodetachment from the dipole-bound state are discussed.

Anomaly in conformal quantum mechanics: From molecular physics to black holes

“…In particular, when binding occurs, extended states known as dipole-bound anions are formed. These conclusions have also been confirmed by detailed ab initio calculations [18,19] and by studies that incorporate the effects of rotational degrees of freedom [20], which also modify slightly the value of p ( * ) .…”

“…When this outline is implemented, according to the procedure of Ref. [17] or its generalization of Appendix A, the existence of a critical dipole moment p ( * ) for binding is predicted; the order of magnitude of its "conformal value," λ ( * ) ≈ 1.279, or p ( * ) ≈ 1.625 D, has been verified in numerous exper-iments [18,19]. In particular, when binding occurs, extended states known as dipole-bound anions are formed.…”

Vibrational Feshbach resonances in near-threshold HOCO−photodetachment: A theoretical study

“…In the threshold region, they agree with the distributions measured by Lu and Continetti [8]. Experimental verification of the dipole bound state mechanism might be found in an experiment performed with a tunable source, such as those that have observed such resonances in enolates [16,44].…”

“…The resonances have been ascribed to a temporary binding of an electron to the dipole field of the molecule [12,13]. Dipole-bound states are also observed in the photodetachment spectrum of various anions [14][15][16][17][18]. Zimmerman et al were one of the first groups to observe sharp resonances in the photoelectron spectrum of the acetophenone enolate anion [14].…”

Effective field theory program for conformal quantum anomalies

“….. However, the experimentally observed bound states [14,15] appear to be limited to the highest root γ 0,0 because of the characteristic order of magnitude of the molecular dipole moments realized in nature.…”