Circular dichroism 2> axial single

Fig. 2. The axial single crystal circular dichroism spectrum (Ae/10) of 2 A-t+XCofenlslCls NaCl 6 H2O (solid curve) and the absorption and CD spectrum of A-(+)-[Co(en)3l(a04)3 in water (upper and lower broken curves, respectively). The axial crystal CD spectrum characterises electronic transitions of the complex ion to upper states of symmetry, polarized perpendicular to the threefold rotation axis of the complex...

The polarised single-crystal spectra of anions where an axial component of the ligand field is expected (XM6024H6(6 b), XM09O32) have not been studied (except in the case of MnMogOjjI in the 14—16,000 cm-1 region (115)). There have been very few measurements of emission spectra (115, 194) or of circular dichroism (115, 129), and no magnetic CD studies. Measurements of these kinds may require the revision of conclusions based on solution absorption spectra. Some work on... 

Circular dichroism studies of the 7a-methyl bicyclic ketol suggested, and a single-crystal X-ray diffraction study of the racemic compound confirmed, the cIS conformation with an axial 7a-methyl and an equatorial 3a-hydroxy group In the six-membered ring of the bicyclic system. On the other hand, similar measurements of the 7a-ethyl bicyclic keto established the alternate possible cis conformation to avoid the 1,3-diaxial interactions between the angular ethyl group and the C-4 and C-6 axial hydrogens. 

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