NQR in Molecular Compounds and Intramolecular Rearrangement

The determination of the asymmetry parameters and the direction cosines, together with x-ray investigations of the crystal structure, will shed some light on the crystal field effect in solids. NQR powder spectra can only permit very rough and qualitative conclusions on the intermolecular forces. The results on the Mentschukin complexes with AsCl3 show that the metal-chlorine bond is virtually unaffected by the formation of molecular compounds. From singlecrystal NQR spectroscopy, particularly on the As nucleus, some geometrical information about the molecular compounds can be expected. 

Similar decreases of j (79 81Br) are found in molecular compounds of AlBr3-X 133 . In these compounds the ionic character is increased by the breakdown of the bridge structure 

In particular, the fact that in all of the compounds CCl3COOH-X and CCl3CO-R the three Cl atoms are crystallographically inequivalent needs further experimental work. 

Cl CgH .. NHCOCHj. Cij, (lower distribution b) in chloroacetanilides, ClxC6Hs.xNHCOCH3.j,Cly, and in trichloroacetic acid (TCA) derivatives from Ref. 1I2) (overall distribution  

Study of the Crystal Field Effect by Continuous Variation of Crystal Field Parameters 

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