The 14N Nuclear Quadrupole Coupling Tensors, the Tensors of the Molecular Magnetic Susceptibility and the Molecular Electric Quadrupole Moment in Pyrazole: A High Resolution Rotational Zeeman Effect Study

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1248-1258 ◽  
Author(s):  
O. Böttcher ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
High Resolution ◽  
Quadrupole Moment ◽  
Moment Tensor ◽  
Electric Quadrupole ◽  
Coupling Constants ◽  
Zero Field ◽  
Electric Quadrupole Moment ◽  
Magnetic Susceptibility Anisotropy ◽  
Quadrupole Coupling

AbstractHigh resolution zero field and Zeeman rotational spectra of 1 D-pyrazole have been studied by microwave Fourier-transform spectroscopy. The zero field hfs patterns allowed to improve the quadrupole coupling constants for both 14N nuclei. From the high field Zeeman multiplets the diagonal elements of the g-tensor were obtained as gaa= -0.1178(2),.gbb=-0.0762(2) and gcc = 0.0608 (2). The two independent components of the molecular magnetic susceptibility anisotropy in units of 10-6 erg G-2 mole- 1 are 2 ξaa - ξbb - ξcc= 52.69(32) and 2 ξbb - ξcc - ξaa = 39.32(29) were, a, b, c denote the molecular principal inertia axes. From these values the components of the molecular electric quadrupole moment tensor in units of 10-26 esu cm2 follow as Qaa = 5.84(22), Qbb= -0.58 (21) and Qcc= -5.27(38). Comparison with corresponding values for the undeuterated species leads to the complete tensors including their orientation with respect to the nuclear frame.

High Resolution Study of the Rotational Spectrum of Formaldoxime, Combined with Quantum Chemical Calculations, Its 14N Spin-Rotation Coupling, 14N Nuclear Quadrupole hfs, and Its Rotational Zeeman-Effect

1990 ◽  
Vol 45 (6) ◽  
pp. 817-826 ◽  
Author(s):  
A. Klesing ◽  
D. H. Sutter
Keyword(s):  
High Resolution ◽  
Quadrupole Moment ◽  
Moment Tensor ◽  
Electric Quadrupole ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Zero Field ◽  
Rotational Spectrum ◽  
Electric Quadrupole Moment ◽  
Resolution Study

AbstractA high resolution study of the rotational spectrum of formaldoxime was carried out with the aim to resolve a discrepancy between early microwave results and recent ab initio calculations. Accurate 14N quadrupole coupling constants and spin-rotation coupling constants could be derived from zero field hfs multiplets. From the Zeeman-splittings in external magnetic fields up to 18kGauss the diagonal elements of the molecular g-tensor and the anisotropics in the diagonal elements of the molecular magnetic susceptibility tensor were obtained and were used to derive the diagonal elements of the molecular electric quadrupole moment tensor. For comparison, Hartree Fock SCF calculations were carried out with a basis of TZVP quality. As it turned out such calculations are able to reproduce the molecular electric quadrupole moment tensor but fail to reproduce the 14N nuclear qudrupole coupling constants to better than 0.3 MHz. A revised formula to predict spinrotation coupling constants of first row elements such as nitrogen is also proposed.

The Rotational Zeeman Effect of Imines II. Cis- and Trans-Ethanimine and Trans-Syn- and Trans-Anti-Propenimine, their g-Tensors, Magnetic Susceptibility Anisotropics, Molecular Electric Quadrupole Moments, 14N Nuclear Quadrupole Coupling Constants, and 14N Spin-Rotation Coupling Constants; a Microwave Spectroscopic Study Combined with Quantum Chemical Calculations

1991 ◽  
Vol 46 (9) ◽  
pp. 785-798 ◽  
Author(s):  
H. Krause ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
High Field ◽  
Moment Tensor ◽  
Electric Quadrupole ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Zero Field ◽  
Quadrupole Moments ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Abstract The zero field 14N-hfs-multiplets and the high-field Zeeman-hfs-multiplets of low-J rotational transitions of the title compounds were observed in a flash pyrolysis setup under high-resolution conditions. From the zero-field hfs patterns the 14N spin-rotation coupling constants and the 14N nuclear quadrupole coupling constants were obtained. From the high-field Zeeman-hfs-multiplets, the diagonal elements of the molecular g-tensor and the anisotropies in the diagonal elements of the molecular magnetic susceptibility tensor were determined and were used to derive the diagonal elements of the molecular electric quadrupole moment tensor. INDO calculations and restricted Hartree-Fock self consistent field calculations with a basis of TZVP quality were carried out at the experimental structures and critically compared to the experimental results

The Rotational Zeeman Effect in Acetone, its g-Tensor, its Magnetic Susceptibility Anisotropics and its Molecular Electric Quadrupole Moment Tensor; A High Resolution Microwave Fourier Transform Study

1992 ◽  
Vol 47 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Frank Oldag ◽  
Dieter H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Fourier Transform ◽  
Quadrupole Moment ◽  
Moment Tensor ◽  
Zeeman Effect ◽  
Electric Quadrupole ◽  
Effect Study ◽  
Rigid Rotor ◽  
Electric Quadrupole Moment ◽  
Asymmetric Top

Abstract Acetone is a molecule with an intermediate barrier for methyl- top internal rotation, and only molecules in the A1A1 - state of the tunneling motion exhibit a rigid rotor spectrum. For this state we report the results of a rotational Zeeman effect study of acetone in exterior fields up to 20 kGauss (2 Tesla). From an analysis of the observed Zeeman splittings within the asymmetric top approximation the nonzero elements of the g-tensor and the magnetic susceptibility anisotropies were obtained as follows: gaa= -0.04379 (8), gbb = - 0.06611 (5), gcc=-O.O1481 (7), 2ξaa -ξbb - ξcc = - 9.53 (21) 10-6 erg G -2 mole-1 and 2 ξbb - ξcc - ξaa = 25.57 (18) 10-6 erg G -2 mole-1 . The nonzero elements of the molecular electric quadrupole moment tensor were derived as Qaa- 2-77 (13) DÅ, Qbb= -4.59 (10) DÅ and Qcc= 1.82 (15) DÅ. Zeeman spectra were also recorded for seveal low-J transitions of molecules in the EE-state of methyl top tunneling (one top tunneling), and so far the same splittings have been found as for the A1 A1-species

Molecular g-Values, Magnetic Susceptibility, Anisotropics, Second Moments of the Electronic Charge Distribution. Molecular Electric Quadrupole Moment, and 14N Nuclear Quadrupole Coupling of Nitroethylene, CH2 = CH - N02

1991 ◽  
Vol 46 (8) ◽  
pp. 715-728
Author(s):  
J. Spiekermann ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
High Field ◽  
Electric Quadrupole ◽  
Coupling Constants ◽  
Electronic Charge ◽  
Electric Quadrupole Moment ◽  
Second Moments ◽  
Quadrupole Coupling ◽  
Electronic Charge Distribution ◽  
Nuclear Quadrupole

AbstractThe high-field linear and quadratic Zeeman effect has been observed in nitroethylene. The spectrum is complicated by the presence of 14N nuclear quadrupole coupling which was reanalyzed from low-J zero-field transitions observed under high resolution. Our 14N quadrupole coupling constants are Xaa = -0.8887(18) MHz, Xbb = +0.0429(29) MHz, Xcc = +0.8458(29) MHz (c-axis perpendicular to the molecular plane). Our g-values and magnetic susceptibility anisotropics, fitted to the observed high-field Zeeman multiplets, are gaa = -0.15 985(39), -0.07197(31), gcc= -0.01080(32), 2ξaa-ξbb-ξcc= + 19.07(43) * 10-6 erg * G-2 * mole-1 and 2ξbb- ξcc- ξaa = + 29.67(53) -10-6 erg * G-2 * mole-1 . From them, the anisotropics in the second moments of the electronic charge distribution and the components of the molecular electric quadrupole moment with respect to the principal inertia axes system follow as <a2> -<b2> = +36.55(7)Å2 , <b2> - <c2>= +23.58(9) Å2, <c2>-<a2> = -60.14(8) Å2, Qaa= -0.59(29) D * Å, Qbb = +0.07(36) D * Å, and Qcc = +0.52(46) D * Å. The 14N quadrupole coupling constants, the anisotropics in the second electronic moments and the quadrupole moments are compared to the corresponding Hartree-Fock SCF values calculated with the Gaussian 88 program. The discrepancy between the experimental values and the ab initio values is considerably larger than found earlier in a similar investigation of a group of imines

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.

scholarly journals NMR Detection of Oxygen Isotopes in TiO2 Single Crystal

1998 ◽  
Vol 53 (6-7) ◽  
pp. 305-308
Author(s):  
M. Tanigaki ◽  
S. Takeda ◽  
K. Matsuta ◽  
Y. Matsumoto ◽  
T. Minamisono ◽  
...  
Keyword(s):  
Single Crystal ◽  
Quadrupole Moment ◽  
Oxygen Isotopes ◽  
Electric Quadrupole ◽  
Coupling Constants ◽  
Quadrupole Moments ◽  
Quadrupole Interactions ◽  
Quadrupole Coupling ◽  
Nmr Signals

Abstract We studied the electric quadrupole interactions of Oxygen isotopes in a TiO2 single crystal. For 13O and 19O nuclei, quadrupole coupling constants were measured by the β-NMR technique, and for the 17O nucleus the FT-NMR technique was utilized. We synthesized a TiO2 single crystal which was enriched in 17O up to 5 atom % to observe NMR signals without any perturbations from impurities. Using the known quadrupole moment of 17O, EFGs at an O site in TiO2 and the quadrupole moments of 13O and 19O were determined.

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