Spectra microwave

Spectroscopy is the most important experimental source of infomiation on intemiolecular interactions. A wide range of spectroscopic teclmiques is being brought to bear on the problem of weakly bound or van der Waals complexes [94, 95]. Molecular beam microwave spectroscopy, pioneered by Klemperer and refined by Flygare, has been used to detemiine the microwave spectra of a large number of weakly bound complexes and obtain stmctiiral infomiation... 

Microwave spectra (giving pure rotational spectra) are especially usefiil for the detection of interstellar molecular ions (in some cases the microwave spectrum has first been observed in interstellar spectra ). 

It is also possible to measure microwave spectra of some more strongly bound Van der Waals complexes in a gas cell ratlier tlian a molecular beam. Indeed, tire first microwave studies on molecular clusters were of this type, on carboxylic acid dimers [jd]. The resolution tliat can be achieved is not as high as in a molecular beam, but bulk gas studies have tire advantage tliat vibrational satellites, due to pure rotational transitions in complexes witli intennolecular bending and stretching modes excited, can often be identified. The frequencies of tire vibrational satellites contain infonnation on how the vibrationally averaged stmcture changes in tire excited states, while their intensities allow tire vibrational frequencies to be estimated. 

ROTATIONAL INFRARED, MILLIMETRE WAVE AND MICROWAVE SPECTRA... 

Rotational infrared, millimetre wave and microwave spectra... 

Table 2 Structure Parameters in Five-membered Rings from Microwave Spectra...

H NMR, chemical shifts, 4, 557 in nematic phase microwave spectra, 4, 537 nitration, 4, 45-46, 49, 603 nitro... 

Methanol, l-isoquinolyl(phenyl)-confonnation, 2, 110 Methanol, pyrimidinyl-synthesis, 3, 113 Methanol, tetrahydropyran-2-yl-microwave spectra, 3, 625 Methantheline as neurotransmitter, 1, 175 therapeutic properties, 3, 882 Methaphenilene biological activity, 4, 911 Methapyrilene biological activity, 4, 911 toxicity, 4, 912 Methaqualone, 3, 150 as anticonvulsant, 1, 166 pyrido[2,3-d]pyrimidine analogues metabolism, 3, 205 as sedative, 1, 166 Metharbitone as anticonvulsant, 1, 166 Methazolamide... 

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