ChemInform Abstract: MOLECULAR G-VALUES, MAGNETIC SUSCEPTIBILITY ANISOTROPIES, SECOND MOMENTS OF THE CHARGE DISTRIBUTION, AND MOLECULAR ELECTRIC QUADRUPOLE MOMENTS IN TRANS- AND CIS-THIOFORMIC ACID

1978 ◽  
Vol 9 (14) ◽  
Author(s):  
G. K. PANDEY ◽  
D. H. SUTTER
Keyword(s):  
Magnetic Susceptibility ◽  
Charge Distribution ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Second Moments ◽  
In Trans

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.

Methyl Nitrate, its Molecular Values, Magnetic Susceptibility Anisotropies, Molecular Electric Quadrupole Moment, Second Moments of the Electronic Charge Distribution, and Electric Field Gradient at the Nitrogen Nucleus

1989 ◽  
Vol 44 (11) ◽  
pp. 1087-1096 ◽  
Author(s):  
J. Spieckermann ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Charge Distribution ◽  
Electric Quadrupole ◽  
Coupling Constants ◽  
Electronic Charge ◽  
Second Moments ◽  
Quadrupole Coupling ◽  
Electronic Charge Distribution ◽  
Methyl Nitrate ◽  
Nuclear Quadrupole

The high field molecular Zeeman effect of low-J rotational transitions has been observed in methyl nitrate. The spectrum is complicated by the presence of the small 14N nuclear quadrupole coupling. Methyl top internal rotating splitting is negligible in the transitions studied here. From line shape analyses the individual satellite frequencies in the Zeeman-hfs-multiplets could be determined with experimental uncertainties typically smaller than ±2 kHz. The molecular Zeeman parameters and the 14N nitrogen coupling constants were fitted simultaneously to the observed splittings. The molecular g-values are gaa = -0.1168(5), gbb= -0.0449(3), and gcc= -0.0235(4). The molecular magnetic susceptibility anisotropies in units of 10-6 erg gauss-2 mol-1 are 2ξaa -ξbb -ξcc = +1.24(54) and 2ξbb - ξcc - ξaa = +13.14(53). The 14N nuclear quadrupole coupling constants are χaa - + 0.308(17) MHz, χbb - χcc -0.262(31) MHz. The molecular electric quadrupole moments calculated from the observed rotational constants and Zeeman parameters in units of 10-26 esu cm2 are Qaa = +3.4(6), Qbb= -4.6(6), and Qcc= +1.2(10). Knowledge of the molecular structure and the molecular g-values also gives the diagonal elements in the paramagnetic susceptibility tensor and the ansiotropies in the second moments of the electronic charge distribution. The results in units of 10-6 era gauss-2 mole-1 are ξpaa = + 118.14(10), ξpbb = +279.73(14), and ξpcc = + 357.40(26), and ⟨a2⟩ - ⟨b2⟩ = + 37.14(14) Å2, ⟨b2⟩ - ⟨c2⟩ = +20.46(22) Å2, and ⟨c2⟩ -⟨a2⟩ = -57.60(21) Å2

Molecular g-Values, Magnetic Susceptibility Anisotropies, Molecular Quadrupole Moments and the Anisotropies in the Electronic Charge Distribution in HNO2-Cis, DNO2-Cis, HNO2-Trans, and DNO2-Trans

1984 ◽  
Vol 39 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Dirk Hübner ◽  
Dieter H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Charge Distribution ◽  
Moment Tensor ◽  
Electronic Charge ◽  
Quadrupole Moments ◽  
Magnetic Susceptibility Anisotropy ◽  
Magnetic Susceptibility Tensor ◽  
Second Moments ◽  
Electronic Charge Distribution ◽  
Out Of Plane

The rotational Zeeman effect of the trans and eis forms of nitrous acid has been studied to yield the diagonal elements of the molecular g-tensor and the anisotropics in the diagonal elements of the magnetic susceptibility tensor. The results are used to calculate the diagonal elements of the molecular electric quadrupole moment tensor and the anisotropics in the second moments of the electronic charge distribution for all four molecular species. These data are compared to the corresponding CNDO/2 values, and the CNDO/2 value for the out of plane second moment of the electronic charge distribution is used together with the experimental anisotropics in the second moments of the electronic charge distribution to derive a semiexperimental value for the molecular bulk susceptibility which is otherwise difficult to obtain. The out-of-plane minus average in-plane magnetic susceptibility anisotropy is discussed with reference to the model of localised atomic susceptibilities and it is shown that the model should be extended to include bond and bond-bond interaction contributions.

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.

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