OPTICAL OBSERVATIONS OF THE STARK EFFECT ON OH

1965 ◽  
Vol 43 (1) ◽  
pp. 144-154 ◽  
Author(s):  
D. H. Phelps ◽  
F. W. Dalby
Keyword(s):  
Dipole Moment ◽  
Electric Fields ◽  
Ground State ◽  
Vibrational State ◽  
Stark Effect ◽  
Ultraviolet Spectrum ◽  
Optical Observations ◽  
Excited Vibrational State ◽  
Vibrational Ground State ◽  
Forbidden Transitions

The ultraviolet spectrum of the OH molecule has been obtained in electric fields up to 64 000 volts per cm. Stark line splittings, broadenings, and field-induced parity-forbidden transitions have been observed. The electric dipole moment of OH in its electronic and vibrational ground state (X2Π) has been determined to be (1.727 ± 0.02) Debyes. The dipole moment in the first excited vibrational state has been found to be about 4% lower.

Microwave Spectrum and Dipole Moment of Methylenecyclobutenone

1974 ◽  
Vol 29 (10) ◽  
pp. 1498-1500 ◽  
Author(s):  
W. Czieslik ◽  
L. Carpentier ◽  
D. H. Sutter
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Ground State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Least Square ◽  
Rotational Constants ◽  
Vibrational Ground State ◽  
Least Square Fit

Abstract The microwave spectrum of Methylenecyclobutenone has been investigated in the vibrational ground state in the range of 8 to 26.5 GHz. From a least square fit of 12 lines with J ≦ 4 the rotational constants have been calculated as A =5.775664±0.000009 GHz, B = 4.312314 ± 0.000007 GHz, C = 2.467814±0.000008 GHz. The inertia defect Δ = - 0.09 amuÅ2 indicates that the molecule is planar. From Stark-effect measurements the components of the molecular electric dipole moment were obtaied as |μa| = 2.04 ± 0.02 D, |μb| = 2.70±0.03 D, |μtotal| = 3.39 ± 0.05 D.

Dipole Moment of CS2 in its ã3A2 State

1975 ◽  
Vol 53 (16) ◽  
pp. 1579-1586 ◽  
Author(s):  
M. Larzillière ◽  
D. A. Ramsay
Keyword(s):  
Dipole Moment ◽  
Matrix Element ◽  
Vibrational State ◽  
Stark Effect ◽  
Ultraviolet Spectrum ◽  
Lower State ◽  
Diagonal Matrix Element ◽  
Near Ultraviolet ◽  
Systematic Discrepancy ◽  
Infrared Data

The Stark effect on the [Formula: see text] system of 12C32S2 has been investigated. The most pronounced effects involve the 270,27 and 261,26 rotational levels of the 140 vibrational state and the 290,29 and 281,28 rotational levels of the 050 vibrational state. These pairs of levels are nearly degenerate and are coupled by an off-diagonal matrix element in the presence of an electric field. An analysis of the Stark shifts and the shapes of the Stark broadened lines yields[Formula: see text]Comparison of these energy separations with values calculated from measurements in the near ultraviolet spectrum and lower state term values based primarily on infrared data reveals a systematic discrepancy of 0.022 cm−1.

Elektrisches Dipolmoment von TlBr und TlJ

1971 ◽  
Vol 26 (11) ◽  
pp. 1809-1812 ◽  
Author(s):  
E. Tiemann
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Vibrational State ◽  
Stark Effect ◽  
Dipole Moments ◽  
Electric Dipole Moments ◽  
Ground Vibrational State ◽  
Rotational Transitions

Stark-effect measurements on pure rotational transitions of TlBr and Til are described. The derived electric dipole moments of the most abundant isotopic molecules on the ground vibrational state are:205TL79Br : | μ0| = (4.493 ± 0.050) D , 205Tl127 I | μ 0| =(4.607 ± 0.070) D .The electric dipole moment of 205Tl19F | μ 0|=4.2282 (8) D was used as standard.

Electric dipole moment of H2O in the ν2 excited vibrational state

1981 ◽  
Vol 75 (10) ◽  
pp. 4869-4872 ◽  
Author(s):  
Hiroaki Kuze ◽  
Takayoshi Amano ◽  
Tadao Shimizu
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Vibrational State ◽  
Excited Vibrational State

High-Field Stark Effects on the Near Ultraviolet Spectrum of the Hydroxyl Radical

1971 ◽  
Vol 49 (22) ◽  
pp. 2825-2832 ◽  
Author(s):  
Ethan A. Scarl ◽  
F. W. Dalby
Keyword(s):  
Dipole Moment ◽  
Hydroxyl Radical ◽  
Electric Fields ◽  
High Field ◽  
Transition Probability ◽  
Ultraviolet Spectrum ◽  
Vibrational Transition ◽  
Near Ultraviolet ◽  
Stark Effects ◽  
Π State

Spectra due to the A2Σ+–X2Π transition of the hydroxyl radical in electric fields of over 300 000 V per cm have been obtained. The dipole moment of the A2Σ+ ν = 0 state of OH has been determined to be (1.98 ± 0.08) D. From the variation of the dipole moment with vibrational quantum number in the 2Π state, the transition probability for the pure vibrational transition ν = 1 →ν = 0 has been estimated to be A10 = 80s−1.

scholarly journals A Preorganized Electric Field Leads to Minimal Geometrical Reorientation in the Catalytic Reaction of Ketosteroid Isomerase

2020 ◽  
Author(s):  
Yufan Wu ◽  
Stephen Fried ◽  
Steven Boxer
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Ground State ◽  
Active Site ◽  
Electrostatic Interactions ◽  
Stark Effect ◽  
Structural Changes ◽  
Enzymatic Catalysis ◽  
Ketosteroid Isomerase ◽  
Computational Enzyme Design

<div><p>Electrostatic interactions play a pivotal role in enzymatic catalysis and are increasingly modeled explicitly in computational enzyme design; nevertheless, they are challenging to measure experimentally. Using vibrational Stark effect (VSE) spectroscopy, we have measured electric fields inside the active site of the enzyme ketosteroid isomerase (KSI). These studies have shown that these fields can be unusually large, but it has been unclear to what extent they specifically stabilize the transition state (TS) relative to a ground state (GS). In the following, we use crystallography and computational modeling to show that KSI’s intrinsic electric field is nearly perfectly oriented to stabilize the geometry of its reaction’s TS. Moreover, we find that this electric field adjusts the orientation of its substrate in the ground state so that the substrate needs to only undergo minimal structural changes upon activation to its TS. This work provides evidence that the active site electric field in KSI is preorganized to facilitate catalysis and provides a template for how electrostatic preorganization can be measured in enzymatic systems. <br></p></div>

Microwave spectrum of allyl cyanide (CH2=CHCH2CN)

1968 ◽  
Vol 46 (8) ◽  
pp. 959-962 ◽  
Author(s):  
K. V. L. N. Sastry ◽  
V. M. Rao ◽  
S. C. Dass
Keyword(s):  
Dipole Moment ◽  
Vibrational State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Effect Measurement ◽  
Rotational Constants ◽  
Molecular Dipole ◽  
Ground Vibrational State ◽  
Molecular Dipole Moment ◽  
Rotational Isomers

The microwave spectrum of allyl cyanide (3-butenonitrile) was studied in the region from 8 to 26 GHz. It was confirmed that this molecule exists in the two rotational isomers "cis" and "gauche". In the cis form, both a- and b-type transitions were assigned and the rotational constants in the ground vibrational state were calculated to be A = 11 323.01 + 0.08 MHz, B = 3739.20 ± 0.01 MHz, C = 2858.52 ± 0.01 MHz. The molecular dipole-moment components are μa = 3.26 ± 0.01 D, μb = 2.16 ± 0.05 D, and μt = 3.91 ± 0.03 D. For the gauche form, the a-type transitions were assigned and the rotational constants in the ground vibrational state are A = 17 295 MHz, B = 2619.91 ± 0.1 MHz, C = 2497.52 ± 0.1 MHz. The Stark effect measurement in this case gave the components of the dipole moment as μa = 3.69 ± 0.02 D, ub = 1.11 ± 0.06 D, μc = 0.98 ± 0.07 D, and μt = 3.98 ± 0.03 D.

Microwave Spectrum of γ-Thiobutyrolactone

1982 ◽  
Vol 37 (2) ◽  
pp. 129-133 ◽  
Author(s):  
José L. Alonso ◽  
J. C. Lopez ◽  
F. Mata
Keyword(s):  
Dipole Moment ◽  
Excited States ◽  
Ground State ◽  
Stark Effect ◽  
Potential Energy Function ◽  
Microwave Spectrum ◽  
Average Intensity ◽  
Vibrational States ◽  
Bending Vibration ◽  
Out Of Plane

Abstract The microwave spectrum of γ-thiobutyrolactone has been observed and measured in the vibra-tional ground state and in several excited states of the ring-bending and ring-twisting modes. From the value of the μc component of the dipole moment and inertial-defect considerations the ring skeleton was shown to be non-planar. The average intensity ratio for the rotational transitions between the ground and excited vibrational states indicates that the first excited state of the ring-bending and ring-twisting modes are ~ 120 cm-1 and ~ 250 cm-1 above the ground state respectively. These two out-of-plane ring vibrations are essentially independent and the ring-bending vibration is governed by a nearly harmonic potential energy function. The components of the dipole moment were determined by the Stark effect to be μa = 3.770 ± 0.001 D, μb = 1.818 ± 0.044 D and μc = 0.832 ± 0.018 D, leading to μtotal = 4.268 ± 0.023 D. The rigidity of the γ-thiobutyrolactone ring is discussed in relation to those of related molecules.

Sign in / Sign up

Export Citation Format

Share Document