Stark effects and electric dipole coupling ofnπ* and ππ* states

1972 ◽  
Vol 24 (3) ◽  
pp. 597-607 ◽  
Author(s):  
Robin M. Hochstrasser
Keyword(s):  
Electric Dipole ◽  
Dipole Coupling ◽  
Stark Effects

High Field Stark Effects in CH and NH

1974 ◽  
Vol 52 (15) ◽  
pp. 1429-1437 ◽  
Author(s):  
E. A. Scarl ◽  
F. W. Dalby
Keyword(s):  
Dipole Moment ◽  
Electric Fields ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
High Field ◽  
Dipole Moments ◽  
Optical Spectra ◽  
Vibrational States ◽  
Stark Effects

A LoSurdo discharge was used to apply electric fields of up to 290 kV/cm to a mixture of cyanogen and hydrogen, and to ammonia, permitting the observation of Stark effects in the optical spectra of the CH and NH molecules, respectively. These experiments yielded the following values of the molecular electric dipole moment in the ground vibrational states: μ(CH, A2Δ) = 0.887 ± 0.045 D, and μ(NH, X3Σ) = 1.389 ± 0.075 D. A table of experimental and theoretical dipole moments of first-row hydrides is included.

The Microwave Spectrum of Imidazole; Complete Structure and the Electron Distribution from Nuclear Quadrupole Coupling Tensors and Dipole Moment Orientation

1981 ◽  
Vol 36 (12) ◽  
pp. 1378-1385 ◽  
Author(s):  
Dines Christen ◽  
John H. Griffiths ◽  
John Sheridan
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Electron Distribution ◽  
Ring Structure ◽  
Microwave Spectrum ◽  
Complete Structure ◽  
Quadrupole Coupling ◽  
Stark Effects ◽  
Nuclear Quadrupole

Spectra have been measured for eleven isotopic forms of imidazole, including single substitutions at each nucleus in turn. A complete rs-structure is obtained. The ring structure is: N(1)-C(2) = 1.364 Å, C(2)-N(3) = 1.314 Å, N(3)-C(4) = 1.382 Å, C(4)-C(5) = 1.364 Å, C(5)-N(1) = 1.377 Å, ≮N(1)C(2)N(3) = 112.0°, ≮C(2)N(3)C(4) = 104.9°, ≮N(3)C(4)C(5) = 110.7°, ≮C(4)C(5)N(1) = 105.5° and ≮C(5)N(1)C(2) = 106.9°. The N(1)-H(1) distance is 0.998 Å, while the C-H distances are all very close to 1.078 Å. The bonds N(1)-H(1) and C(2)-H(2) lie close to the external bisectors of the respective ring angles, but C(4)-H(4) and C(5)-H(5) are each displaced by several degrees from these bisectors towards N(3) and N(1) respectively. The electric dipole moment is established as 3.67 (5) D from Stark effects, directed almost parallel with the line joining the nitrogen nuclei. The properties and orientations of the two 14N-nuclear quadrupole tensors have been investigated, in particular through the spectra of the two mono-14N-imidazoles.

The Microwave Spectrum of 2,6-Difluoropyridine

1976 ◽  
Vol 31 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Otto L. Stiefvater ◽  
Stephen Lui ◽  
John A. Ladd
Keyword(s):  
Dipole Moment ◽  
Electric Dipole ◽  
Electron Distribution ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Quadrupole Coupling ◽  
Stark Effects ◽  
Structural Differences ◽  
Hyperfine Splittings ◽  
Rotation Spectrum

Hyperfine splittings of rotational transitions of 2,6-difluoropyridine have been analysed to yield the 14N quadrupole coupling constants. Their values are:Χaa = 1.82 ± 0.05 MHz, Χbb = - 4.16 ± 0.02 MHz, Χcc = 2.34 ± 0.05 MHz. The electric dipole moment has been determined from Stark effects as fi = 3.82 ± 0.06 D, and satellites in the rotation spectrum have been correlated with the five lowest fundamental vibrations of this molecule.The dipole moment, the quadrupole data and the structural differences between 2,6-difluoropyridine and pyridine itself can all be accounted for by the change in the electron distribution due to the fluorine substituents.

Sign in / Sign up

Export Citation Format

Share Document