Inversion angle

The inversion angle of 2,4-disilabicyclo[1.1.0]butane derivative 47 was calculated from the geometrical parameters by the X-ray analysis [43] to be larger (11.9°) (Scheme 17) than 45. This supports the prediction of the dependence of the inversion... 

Scheme 17 The inversion angle and X-ray geometrical parameters used to calculate...

The disila- 52 [48, 49] and digermabridged 53 [50] were synthesized and their X-ray analyses were performed. The inversion angle of 38.8° for 52 and extremely long M-M (M=Si, Ge) bond lengths were observed (Scheme 21). The inverted configuration was consistent with both the NMR data and the simulation. 

Cramer, C. J. 1991. Dependence of Isotropic Hyperfine Coupling in the Fluoromethyl Radical Series on Inversion Angle J. Org. Chem., 56, 5229. 

The model permits to determine spectroscopic constants, as well as to optimize the geometry in the lowest excited singlet state. The theoretical structures, inversion angles and barrier heights obtained for cyclobutanone and... 

In the 1920s, Lyot [36] discovered that the polarization plane of the reflected light from the Moon and different terrestrial materials rotates by 90 at a phase angle called the inversion angle A branch of negative polarization at phase angles smaller than was also observed. Later it was discovered that this phase dependence is typical of all atmosphereless solar... 

It is not surprising that for planets with dense atmospheres, it is impossible to identily common features in the phase and spectral dependences of the degree of linear polarization and in the spectral dependence of the inversion angle. Indeed, these quantities are detemtined by the morphology, chemical composition, size, and vertical distribution of cloud particles, which appear to be vastly different in various planetary atmospheres. 

The Martian atmosphere is characterized by a small value of the optical thickness. Therefore polarization properties of the reflected light are formed both by the underlying surface and the gas-aerosol atmosphere. One fortunate exception occurs at phase angles near the inversion angle orf of the surface, where the resulting polarization P a-) is formed only by the Martian atmosphere. In modehng the first-order scattering, the expression for the observed Q value becomes... 

It is impossible to analyze the observational data without some simplifications, but it is necessary to reduce to a minimum their number, and it is necessary that their uncertainty have httle effect on the precision of the estimated parameters. So, for example, the effect of the assumption that the inversion angle of the underlying surface is wavelength independent can be diminished considerably if one uses observational data in the far ultraviolet region of the spectrum, where the contribution of the atmosphere to Q a, 1) is large. 

Parameters P n and slope AP/Aa at the inversion angle ainv = 2 ° show a tendency to increase slightly in the visible domain for dust-rich comets. This result was obtained by comparison of trigonometric fits for the phase-angle dependence of polarization for dust-rich comets in the blue and red domain [40]. This tendency was recently confirmed by observations of comet C/2000 WMl (LINEAR) [77]. It should be noted that the negative polarization branch of comet... 

Ab initio calculated electronic potential energy E and inversion angle 0 (angle H-C-X, cf. Fig. 9) along the minimal energy reaction path for the 5j 2-reaction H +H C-H H-CH +H. ... 

The NCN angle is 180° + bp, where b is the backbend parameter. The cyanide nitrogen is tilted away from the Itydrogens by 5.2° at an inversion angle of 45°. 

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