Molecular Zeeman effect of 3-oxetanone and 3-methylene oxetane, and the comparison of the magnetic-susceptibility anisotropies, molecular quadrupole moments, and other magnetic parameters with other four-membered rings

1973 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
C.L. Norris ◽  
H.L. Tigelaar ◽  
W.H. Flygare
Keyword(s):  
Magnetic Susceptibility ◽  
Zeeman Effect ◽  
Quadrupole Moments ◽  
Magnetic Parameters

scholarly journals The Molecular Zeeman Effect of Imines. I. Methanimine, its Molecular g-Tensor, its Magnetic Susceptibility Anisotropies, its Molecular Electric Quadrupole Moment, its Electric Field Gradient at the Nitrogen Nucleus, and its Nitrogen Spin-Rotation Coupling

1989 ◽  
Vol 44 (11) ◽  
pp. 1063-1078 ◽  
Author(s):  
H. Krause ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Zero Field ◽  
Quadrupole Moments ◽  
Magnetic Susceptibility Tensor ◽  
State Expectation ◽  
The Individual

Abstract The rotational Zeeman effect has been observed in methanimine which was produced from ethylenediamine by flash pyrolysis. The observed vibronic ground state expectation values of the molecular g-values, the magnetic susceptibility anisotropies and the molecular electric quadrupole moments are: gaa = -1.27099(22), gbb= -0.18975(7), gcc= -0.03440(8), 2ξaa-ξbb-ξcc = 12.49(19) · 10-6 ergG-2mol-1, 2ξbb-ξcc-ξaa = 5.22(11) · 10-6 ergG-2 mol-1 Qaa = 0.43(17) · 10-26esu cm2, Qbb= 1.08(10) · 10-26 esu cm2, and Qcc= -1.51 (26) . 10-26 esu cm2. With the TZVP ab initio value for the out-off plane electronic second moment as additional input, reliable values can be given also for the individual components of the magnetic susceptibility tensor and for the bulk susceptibility:ξ = (ξaa + ξbb + ξcc)/3=-13.13(88) · 10-6 erg G -2 mol-1. From low-J a-and b-type zero field transitions the spin-rotation coupling constants and the 14N nuclear quadrupole coupling constants could be redetermined with improved accuracy. These data are compared with our new theoretical results.

scholarly journals The Rotational Zeeman Effect in Fluorobenzene and the Molecular Quadrupole Moment in Benzene

1982 ◽  
Vol 37 (10) ◽  
pp. 1165-1175 ◽  
Author(s):  
W. H. Stolze ◽  
M. Stolze ◽  
D. Hübner ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Carbon Tetrachloride ◽  
Quadrupole Moment ◽  
Ring Current ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Electric Quadrupole Moment ◽  
Microwave Spectrometer ◽  
Out Of Plane

The rotational Zeeman effect in fluorobenzene is reinvestigated with a resolution improved by a factor of almost five to give more accurate g-tensor elements, magnetic susceptibility anisotropics and molecular electric quadrupole moments. The results fit into the pictures of a linear dependence of the out of plane molecular electric quadrupole moment, Qcc, on the number of fluorine substituents and of a linear correlation between the nonlocal (ring current) susceptibility, Χccnonlocal, and the CNDO/2-π-electron density alternation. They lead to a gasphase molecular electric quadrupole moment in benzene, Qcc,benzene = - (28.4 ± 4.7) · 10-40 Cm2 which is slightly less negative than the value deduced from electric field-gradient birefringence experiments on dilute benzene solutions with carbon tetrachloride as solvent. A detailed description of the high resolution microwave spectrometer is given in the appendix.

Molecular g-Values, Magnetic Susceptibility Anisotropics, Second Moments of the Charge Distribution, and Molecular Electric Quadrupole Moments in trans- and cis-Thioformic Acid

1978 ◽  
Vol 33 (1) ◽  
pp. 29-37 ◽  
Author(s):  
G. K. Pandey ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Charge Distribution ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Covalent Bonding ◽  
Microwave Spectrum ◽  
Quadrupole Moments ◽  
Second Moments ◽  
In Trans ◽  
Single Standard

The rotational Zeeman effect in the microwave spectrum of trans- and cis-Thioformic Acid has been investigated at field strengths upto 25.6 kG. Measurements were done for both ⊿M = 0 and ⊿M = ± 1 selection rules for the trans species and for ⊿M = ±1 for the cis species. From the observed splittings the following parameters were obtained for the diagonal elements of the molecular g tensor and the susceptibility anisotropics.(all experimental uncertinties are single standard deviations).The molecular electric quadrupole moments derived from the Zeeman data indicate that there is no significant covalent bonding in the O…H region of the trans species.

Molecular Values, Magnetic Susceptibility Anisotropies and Molecular Electric Quadrupole Moments of Difluoroacetonitrile. A Rotational Zeeman Effect Study

1987 ◽  
Vol 42 (2) ◽  
pp. 167-173 ◽  
Author(s):  
J. Spieckermann ◽  
M. Andolfatto ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Effect Study ◽  
Nitrile Group ◽  
Group Comparison ◽  
Quadrupole Moments ◽  
Susceptibility Tensor ◽  
Magnetic Susceptibility Tensor ◽  
Electron Withdrawal

The rotational Zeeman effect of several low J rotational transitions of difluoroacetonitrile has been studied under high resolution conditions with a microwave superheterodyne bridge spectrometer. The observed anisotropies in the molecular magnetic susceptibility tensor are discussed within the model of local susceptibilities to derive the magnetic susceptibility tensor of the nitrile group. Comparison with results obtained earlier for acrylonitrile shows significant changes, probably due to electron withdrawal from the CN-group by the neighbouring fluorine atoms.

Molecular g-Values, Magnetic Susceptibility Anisotropics and Molecular Electric Quadrupole Moment of Methylenecyclobutenone

1974 ◽  
Vol 29 (12) ◽  
pp. 1820-1826 ◽  
Author(s):  
W. Czieslik ◽  
D. H. Sutter
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Quadrupole Moment ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Electric Quadrupole Moment ◽  
Ring Molecules ◽  
Indo Calculations ◽  
Additivity Rules

The rotational Zeeman-effect of methylenecyclobutenone has been investigated giving the molecular (g-values: gaa = -0.0925 ± 0.0003, gbb = -0.0729 ±0.0003, gcc = -0.0086 ± 0.0003 and the magnetic susceptibility anisotropies: 2χaa-χbb-χcc= (23.0 ± 0.5) · 10-6 erg/G2 mole and 2χbb-χcc-χaa= (25.5 ± 0.5) · 10-6 erg/G2 mole. These values correspond to the following molecular electric quadrupole moments given in units of 10-28 esu cm2: Qaa = 1.0±0.6, Qbb= 2.8±0.6 and Qcc = 3.8± 1.0. The experimental data of methylenecyclobutenone and similar strained ring molecules are compared with the results of INDO-calculations and values obtained from additivity rules for bond contributions.

The Molecular 0-Tensor, the Magnetic Susceptibility Anisotropy, and the Molecular Electric Quadrupole Moment Tensor of Monofluoroacetonitrile, a Rotational Zeeman Effect Study

1991 ◽  
Vol 46 (12) ◽  
pp. 1049-1054
Author(s):  
H. Krause ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Moment Tensor ◽  
Zeeman Effect ◽  
Heavy Atom ◽  
Electric Quadrupole ◽  
Effect Study ◽  
Field Calculation ◽  
Quadrupole Moments ◽  
Magnetic Susceptibility Anisotropy ◽  
Magnetic Susceptibility Tensor

Abstract The rotational Zeeman effect of H2F12C12C14N was observed at fields up to 20 kG (2 Tesla). The observed vibronic ground state expectation values for the molecular ^-values, the magnetic susceptibility anisotropies and the molecular electric quadrupole moments, all referred to the molecular principal inertia axes system, are: gaa= -0.03572 (11), gbb= -0.03438 (7), gcc= -0.03988 (6). 2ξaa- ξbb - ξcc = - 14.58 (10) • 10-6 erg/(G2 mole), 2ξaa- ξbb - ξcc= 1.60 (11) • 10-6 erg/(G2 mole), Qaa= -9.13 (6) DÅ, Qbb = 4M (7) DÅ, and Qcc = 4.96 (9) DÅ, respectively. The latter are in close agreement with the results of a restricted Hartree Fock self consistent field calculation with a basis of TZVP quality, which was carried out at the partial restructure determined earlier. Therefore the RHF/TZVP-value for the second electronic moment perpendicular to the heavy atom plane, <0|Σ c2c|0)RHF, was used as additional input to predict the molecular bulk susceptibility and the individual components of the magnetic susceptibility tensor

Nonlocal Susceptibilities and Molecular Electric Quadrupole Moments of 3-Fluoropyridine and 2,6-Difluoropyridine, a Rotational Zeeman Effect Study

1981 ◽  
Vol 36 (4) ◽  
pp. 332-346 ◽  
Author(s):  
D. Hübner ◽  
M. Stolze ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Effect Study ◽  
Quadrupole Moments ◽  
Molecular Plane ◽  
Magnetic Susceptibilities ◽  
Straight Line ◽  
Out Of Plane ◽  
Experimental Values

The rotational Zeeman effect spectra of 3-Fluoropyridine and 2,6-Difluoropyridine have been measured. The molecular g-values are gaa = - 0.0917(5), gbb = - 0.0476(5), gcc = +0.0194(5) for 3-Fluoropyridine and gaa= -0.0573(6), gbb =0.0311(6), gcc =0.0102(6) for 2,6-Difluoro- pyridine. The values for the magnetic susceptibility anisotropics in units of 10-6 erg/(G2 mol) are 2Xaa+Xbb + Xcc = 53.3(8), 2Xbb-Xcc-Xaa = 60.5(7) for 3-Fluoropyridine and 2Xaa-Xbb -Xcc = 48.4(11), 2Xbb-Xcc-Xaa=51.7(11) for 2,6-Difluoropyridine. Subtraction of the local atom contributions to the magnetic susceptibilities indicates that Fluorine quenching of the nonlocal out of plane contribution depends on the position of the substituent. Further, the data suggest a linear correlation between X⟂nonlocal and the “CNDO/2-π-density alternation”, which is used to predict susceptibility anisotropics of Fluorobenzenes and Fluoropyridines not yet measured.The molecular quadrupole moments are calculated from the Zeeman data and compared with the experimental values obtained for various fluorosubstituted Pyridines and Benzenes. If the quadrupole moments perpendicular to the molecular plane are referred to the centers of the six membered rings and are plotted against the number of Fluoroine substituents, nF, the plots closely follow a straight line with identical slopes for the Pyridine- and Benzenefamilies, but with different intercepts at nF = 0. From the “nF = 0 intercept” for the Fluorobenzenes we conclude that the Benzene quadrupole moment proposed earlier by Shoemaker and Flygare should probably be revised

Sign in / Sign up

Export Citation Format

Share Document