Renner−Teller and Fermi Resonance Interactions for the v3= 1 and v7= 2 Vibronic Levels in the A2Πuand X2ΠgElectronic States of HC4H+

2011 ◽  
Vol 115 (34) ◽  
pp. 9365-9369 ◽  
Author(s):  
Ranjini Raghunandan ◽  
Fabio J. Mazzotti ◽  
Aaseef M. Esmail ◽  
John P. Maier
Keyword(s):  
Fermi Resonance ◽  
Resonance Interactions

Triethylammonium halides, Et3NHX (X = Cl, Br, I): simple structure, complex spectrum

1985 ◽  
Vol 63 (7) ◽  
pp. 1750-1758 ◽  
Author(s):  
Margaret Ann James ◽  
T. Stanley Cameron ◽  
Osvald Knop ◽  
Murray Neuman ◽  
Michael Falk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Ir Spectra ◽  
Structure Determination ◽  
Room Temperature ◽  
Simple Structure ◽  
Fermi Resonance ◽  
Crystal Structure Determination ◽  
Complex Spectrum ◽  
Resonance Interactions

A crystal structure determination has shown that the ethyl groups in the three isostructural (P63mc, Z = 2) triethylammonium halides, Et3NHX (X = Cl, Br, I), at room temperature are orientationally disordered and the [Formula: see text] groups are linear by symmetry. The unusual extent and complexity of the NH and ND stretching absorptions in the ir spectra of all three compounds between 10 and 293 K are discussed in terms of Fermi resonance interactions. The centroid ν(NH) and ν(ND) frequencies extracted from the spectra correlate with the [Formula: see text] distances. It is shown that if Fermi resonance is the sole cause of the complexity of the stretching absorptions, then these centroids represent the ν(NH) and ν(ND) frequencies unperturbed by Fermi resonance. The centroid frequencies in the three halides are unusually low, pointing to strong [Formula: see text] hydrogen bonding.

The and band systems of the CS2+ ion

1976 ◽  
Vol 54 (19) ◽  
pp. 1969-1978 ◽  
Author(s):  
Walter J. Balfour
Keyword(s):  
Bond Length ◽  
Electronic States ◽  
Electron Excitation ◽  
Fermi Resonance ◽  
A Value ◽  
Medium Resolution ◽  
Resonance Interactions

The [Formula: see text] and [Formula: see text] emission systems of the CS2+ ion have been photographed at medium resolution following controlled electron excitation of CS2 gas. Vibrational analyses have been performed for both systems. The (0010)–(0010) transitions of the [Formula: see text] and [Formula: see text] subsystems lie at 21 107 and 20 843 cm−1, respectively. Evidence is presented for Fermi resonance interactions between (100) and (020) levels in the [Formula: see text] and [Formula: see text] electronic states. The rotational structures of six partially resolved subbands of the [Formula: see text] system have been studied and a value of 1.615 Å obtained for the C—S bond length of CS2+ in the [Formula: see text] state.

Sign in / Sign up

Export Citation Format

Share Document