Microwave rotational spectroscopy

R. Varma and L. W. Hmbesh, Chemical Analysis by Microwave Rotational Spectroscopy,]ohxi Wiley Sons, Inc., New York, 1979. 

Vol. 51 Trace Element Analysis of Geological Materials. By Roger D. Reeves and Robert R. Brooks Vol. 52 Chemical Analysis by Microwave Rotational Spectroscopy. By Ravi Varma and Lawrence... 

Whilst the most important examples of Zeeman and Stark effects in 1A states are found in molecular beam studies, they can also be important in conventional absorption microwave rotational spectroscopy, as we describe in chapter 10. The use of the Stark effect to determine molecular dipole moments is a very important example. 

In order to assign the Zeeman patterns for the three lowest rotational levels quantitatively, one must determine the spacings between the rotational levels, and the values of g/and gr-In the simplest model which neglects centrifugal distortion, the rotation spacings are simply B0. /(./ + 1) this approximation was used by Brown and Uehara [10], who used the rotational constant B0 = 21295 MHz obtained by Saito [12] from pure microwave rotational spectroscopy (see later in the next chapter). The values of the g-factors were found to be g L = 0.999 82, gr = —(1.35) x 10-4. Note that because of the off-diagonal matrix elements (9.6), the Zeeman matrices (one for each value of Mj) are actually infinite in size and must be truncated at some point to achieve the desired level of accuracy. In subsequent work Miller [14] observed the spectrum of A33 SO in natural abundance 33 S has a nuclear spin of 3/2 and from the hyperfine structure Miller was able to determine the magnetic hyperfine constant a (see below for the definition of this constant). 

ACCURATE MOLECULAR STRUCTURE FROM MICROWAVE ROTATIONAL SPECTROSCOPY"... 

From its inception, microwave rotational spectroscopy has contributed greatly to our knowledge about classical inorganic compounds. It all began with a low resolution recording of the ammonia inversion spectrum in 1934. The first high resolution microwave spectra were recorded... 

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