Molecular Zeeman Effect of Dimethyl Ether and Dimethyl Sulfide; and Comparison of the Magnetic Susceptibility Anisotropies with Ethylene Sulfide and Ethylene Oxide

1970 ◽  
Vol 52 (10) ◽  
pp. 5291-5298 ◽  
Author(s):  
R. C. Benson ◽  
W. H. Flygare
1989 ◽  
Vol 44 (11) ◽  
pp. 1063-1078 ◽  
Author(s):  
H. Krause ◽  
D. H. Sutter

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.


1968 ◽  
Vol 46 (6) ◽  
pp. 987-993 ◽  
Author(s):  
J. P. Guertin ◽  
M. Onyszchuk

Tensimetric titrations at −78° of silicon tetrafluoride with ethylene oxide, trimethylene oxide, tetrahydrofuran, tetrahydropyran, and dimethyl ether prove the formation of only 1:2 complexes, SiF4•2-(ether). All are unstable at 25° and either dissociate completely, as do SiF4•2(CH2)4O, SiF4•2(CH2)5O, and SiF4•2(CH3)2O, or decompose into SiF4 and a polymethylene oxide polymer, as do SiF4•2(CH2)2O and SiF4•2(CH2)3O. Silicon tetrafluoride does not coordinate with 1,4-dioxane in the range −94 to 25° and less than 1 atm pressure. Condensed phase heats of dissociation of SiF4•2(ether) complexes follow the order (CH2)3O > (CH2)4O > (CH2)5O ≥ (CH2)2O > (CH3)2O, which suggests that this is the relative order of basicities towards SiF4.


1982 ◽  
Vol 37 (10) ◽  
pp. 1165-1175 ◽  
Author(s):  
W. H. Stolze ◽  
M. Stolze ◽  
D. Hübner ◽  
D. H. Sutter

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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